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connection handling modularization (#857)

Browse Source 
The main purpose of this PR is to modularize the communication library,
and streamline the code paths for TCP and UDP into a single flow. This
will help us add additional flows such as TLS, and also make sure these
communication functions return a known set of error codes so that
additional error codes can be added for new flows in the future.

It also adds a new optional callback of
`ares_set_notify_pending_write_callback()` that will assist in
aggregating data from multiple queries into a single write operation.
This doesn't apply to UDP, but on TCP and especially TLS in the future
this can be a significant win. This is automatically applied for the
Event Thread.

It also fixes a long standing issue if UDP connection became saturated
and started returning `EWOULDBLOCK` or `EAGAIN` it was treated as a
failure. Since this is more inline with the TCP code now, it will wait
on a write event to retry.

Finally there are additional cleanups due to not needing to be able to
retrieve socket errnos all over the place.

Authored-By: Brad House (@bradh352)
pull/863/head
Brad House 3 months ago committed by GitHub
parent 1b5473fbb9
commit d4ecf95be5
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GPG Key ID: B5690EEEBB952194
23 changed files with 1016 additions and 644 deletions
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  1. 3
      docs/Makefile.inc
  2. 7
      docs/ares_inet_pton.3
  3. 3
      docs/ares_process_fd.3
  4. 3
      docs/ares_process_pending_write.3
  5. 62
      docs/ares_set_notify_pending_write_callback.3
  6. 8
      include/ares.h
  7. 9
      src/lib/ares__close_sockets.c
  8. 545
      src/lib/ares__socket.c
  9. 10
      src/lib/ares__sortaddrinfo.c
  10. 2
      src/lib/ares_destroy.c
  11. 4
      src/lib/ares_inet_net_pton.h
  12. 32
      src/lib/ares_init.c
  13. 87
      src/lib/ares_private.h
  14. 500
      src/lib/ares_process.c
  15. 134
      src/lib/ares_setup.h
  16. 12
      src/lib/ares_update_servers.c
  17. 2
      src/lib/event/ares_event.h
  18. 25
      src/lib/event/ares_event_thread.c
  19. 37
      src/lib/inet_net_pton.c
  20. 29
      src/lib/inet_ntop.c
  21. 5
      src/lib/legacy/ares_fds.c
  22. 3
      src/lib/legacy/ares_getsock.c
  23. 2
      src/lib/str/ares__buf.c

3
docs/Makefile.inc
Unescape View File

@ -114,6 +114,8 @@ MANPAGES = ares_cancel.3 \
ares_parse_txt_reply.3 \
ares_parse_uri_reply.3 \
ares_process.3 \
ares_process_fd.3 \
ares_process_pending_write.3 \
ares_query.3 \
ares_query_dnsrec.3 \
ares_queue.3 \
@ -128,6 +130,7 @@ MANPAGES = ares_cancel.3 \
ares_set_local_dev.3 \
ares_set_local_ip4.3 \
ares_set_local_ip6.3 \
ares_set_notify_pending_write_callback.3 \
ares_set_server_state_callback.3 \
ares_set_servers.3 \
ares_set_servers_csv.3 \

7
docs/ares_inet_pton.3
Unescape View File

@ -9,7 +9,7 @@ ares_inet_pton \- convert an IPv4 or IPv6 address from text to binary form
.nf
#include <ares.h>
const char *ares_inet_pton(int \fIaf\fP, const char *\fIsrc\fP, void *\fIdst\fP);
int ares_inet_pton(int \fIaf\fP, const char *\fIsrc\fP, void *\fIdst\fP);
.fi
.SH DESCRIPTION
This is a portable version with the identical functionality of the commonly
@ -22,6 +22,11 @@ shall be supported. The \fBsrc\fP argument points to the string being passed
in. The \fBdst\fP argument points to a buffer into which the function stores
the numeric address; this shall be large enough to hold the numeric address
(32 bits for AF_INET, 128 bits for AF_INET6).
It returns 1 if the address was valid for the specified address family, or 0
if the address was not parseable in the specified address family, or -1 if
some system error occurred (in which case errno will have been set).
.SH SEE ALSO
.BR ares_init (3),
.BR ares_inet_ntop (3)

3
docs/ares_process_fd.3
Unescape View File

@ -0,0 +1,3 @@
.\" Copyright (C) 2023 The c-ares project and its contributors.
.\" SPDX-License-Identifier: MIT
.so man3/ares_process.3

3
docs/ares_process_pending_write.3
Unescape View File

@ -0,0 +1,3 @@
.\" Copyright (C) 2023 The c-ares project and its contributors.
.\" SPDX-License-Identifier: MIT
.so man3/ares_set_notify_pending_write_callback.3

62
docs/ares_set_notify_pending_write_callback.3
Unescape View File

@ -0,0 +1,62 @@
.\"
.\" Copyright 2024 by the c-ares project and its contributors
.\" SPDX-License-Identifier: MIT
.\"
.TH ARES_SET_NOTIFY_PENDING_WRITE_CALLBACK 3 "13 Aug 2024"
.SH NAME
ares_set_notify_pending_write_callback, ares_process_pending_write \- Function
for setting a callback which is triggered when there is potential pending data
which needs to be written.
.SH SYNOPSIS
.nf
#include <ares.h>
typedef void (*ares_notify_pending_write_callback)(void *\fIdata\fP);
void ares_set_notify_pending_write_callback(
ares_channel_t *\fIchannel\fP,
ares_notify_pending_write_callback \fIcallback\fP,
void *\fIuser_data\fP);
void ares_process_pending_write(ares_channel_t *\fIchannel\fP);
.fi
.SH DESCRIPTION
The \fBares_set_notify_pending_write_callback(3)\fP function sets a callback
function \fIcallback\fP in the given ares channel handle \fIchannel\fP that
is invoked whenever there is new pending TCP data to be written. Since TCP
is stream based, if there are multiple queries being enqueued back to back they
can be sent as one large buffer. Normally a \fBsend(2)\fP syscall operation
would be triggered for each query.
When setting this callback, an event will be triggered when data is buffered,
but not written. This event is used to wake the caller's event loop which
should call \fBares_process_pending_write(3)\fP using the channel associated
with the callback. Each time the callback is triggered must result in a call
to \fBares_process_pending_write(3)\fP from the caller's event loop otherwise
stalls and timeouts may occur. The callback \fBmust not\fP call
\fBares_process_pending_write(3)\fP directly as otherwise it would invalidate
any advantage of this use-case.
This is considered an optimization, especially when using TLS-based connections
which add additional overhead to the data stream. Due to the asyncronous nature
of c-ares, there is no way to identify when a caller may be finished enqueuing
queries via any of the possible public API calls such as
\fBares_getaddrinfo(3)\fP or \fBares_search_dnsrec(3)\fP, so this is an
enhancement to try to group query send operations together and will rely on the
singaling latency involved in waking the user's event loop.
If no callback is set, data will be written immediately to the socket, thus
bypassing this optimization.
This option cannot be used with \fIARES_OPT_EVENT_THREAD\fP passed to
\fBares_init_options(3)\fP since the user has no event loop. This optimization
is automatically enabled when using the Event Thread as it sets the callback
for its own internal signaling.
.SH AVAILABILITY
This function was first introduced in c-ares version 1.34.0.
.SH SEE ALSO
.BR ares_init_options (3)

8
include/ares.h
Unescape View File

@ -460,6 +460,8 @@ typedef void (*ares_server_state_callback)(const char *server_string,
ares_bool_t success, int flags,
void *data);
typedef void (*ares_notify_pending_write_callback)(void *data);
CARES_EXTERN int ares_library_init(int flags);
CARES_EXTERN int ares_library_init_mem(int flags, void *(*amalloc)(size_t size),
@ -526,6 +528,12 @@ CARES_EXTERN void
ares_server_state_callback callback,
void *user_data);
CARES_EXTERN void ares_set_notify_pending_write_callback(
ares_channel_t *channel, ares_notify_pending_write_callback callback,
void *user_data);
CARES_EXTERN void ares_process_pending_write(ares_channel_t *channel);
CARES_EXTERN int ares_set_sortlist(ares_channel_t *channel,
const char *sortstr);

9
src/lib/ares__close_sockets.c
Unescape View File

@ -52,18 +52,19 @@ void ares__close_connection(ares_conn_t *conn, ares_status_t requeue_status)
ares__htable_asvp_remove(channel->connnode_by_socket, conn->fd);
if (conn->flags & ARES_CONN_FLAG_TCP) {
/* Reset any existing input and output buffer. */
ares__buf_consume(server->tcp_parser, ares__buf_len(server->tcp_parser));
ares__buf_consume(server->tcp_send, ares__buf_len(server->tcp_send));
server->tcp_conn = NULL;
}
ares__buf_destroy(conn->in_buf);
ares__buf_destroy(conn->out_buf);
/* Requeue queries to other connections */
ares__requeue_queries(conn, requeue_status);
ares__llist_destroy(conn->queries_to_conn);
SOCK_STATE_CALLBACK(channel, conn->fd, 0, 0);
ares__conn_sock_state_cb_update(conn, ARES_CONN_STATE_NONE);
ares__close_socket(channel, conn->fd);
ares_free(conn);

545
src/lib/ares__socket.c
Unescape View File

@ -79,6 +79,94 @@
#endif
/* Macro SOCKERRNO / SET_SOCKERRNO() returns / sets the *socket-related* errno
* (or equivalent) on this platform to hide platform details to code using it.
*/
#ifdef USE_WINSOCK
# define SOCKERRNO ((int)WSAGetLastError())
# define SET_SOCKERRNO(x) (WSASetLastError((int)(x)))
#else
# define SOCKERRNO (errno)
# define SET_SOCKERRNO(x) (errno = (x))
#endif
/* Portable error number symbolic names defined to Winsock error codes. */
#ifdef USE_WINSOCK
# undef EBADF /* override definition in errno.h */
# define EBADF WSAEBADF
# undef EINTR /* override definition in errno.h */
# define EINTR WSAEINTR
# undef EINVAL /* override definition in errno.h */
# define EINVAL WSAEINVAL
# undef EWOULDBLOCK /* override definition in errno.h */
# define EWOULDBLOCK WSAEWOULDBLOCK
# undef EINPROGRESS /* override definition in errno.h */
# define EINPROGRESS WSAEINPROGRESS
# undef EALREADY /* override definition in errno.h */
# define EALREADY WSAEALREADY
# undef ENOTSOCK /* override definition in errno.h */
# define ENOTSOCK WSAENOTSOCK
# undef EDESTADDRREQ /* override definition in errno.h */
# define EDESTADDRREQ WSAEDESTADDRREQ
# undef EMSGSIZE /* override definition in errno.h */
# define EMSGSIZE WSAEMSGSIZE
# undef EPROTOTYPE /* override definition in errno.h */
# define EPROTOTYPE WSAEPROTOTYPE
# undef ENOPROTOOPT /* override definition in errno.h */
# define ENOPROTOOPT WSAENOPROTOOPT
# undef EPROTONOSUPPORT /* override definition in errno.h */
# define EPROTONOSUPPORT WSAEPROTONOSUPPORT
# define ESOCKTNOSUPPORT WSAESOCKTNOSUPPORT
# undef EOPNOTSUPP /* override definition in errno.h */
# define EOPNOTSUPP WSAEOPNOTSUPP
# define EPFNOSUPPORT WSAEPFNOSUPPORT
# undef EAFNOSUPPORT /* override definition in errno.h */
# define EAFNOSUPPORT WSAEAFNOSUPPORT
# undef EADDRINUSE /* override definition in errno.h */
# define EADDRINUSE WSAEADDRINUSE
# undef EADDRNOTAVAIL /* override definition in errno.h */
# define EADDRNOTAVAIL WSAEADDRNOTAVAIL
# undef ENETDOWN /* override definition in errno.h */
# define ENETDOWN WSAENETDOWN
# undef ENETUNREACH /* override definition in errno.h */
# define ENETUNREACH WSAENETUNREACH
# undef ENETRESET /* override definition in errno.h */
# define ENETRESET WSAENETRESET
# undef ECONNABORTED /* override definition in errno.h */
# define ECONNABORTED WSAECONNABORTED
# undef ECONNRESET /* override definition in errno.h */
# define ECONNRESET WSAECONNRESET
# undef ENOBUFS /* override definition in errno.h */
# define ENOBUFS WSAENOBUFS
# undef EISCONN /* override definition in errno.h */
# define EISCONN WSAEISCONN
# undef ENOTCONN /* override definition in errno.h */
# define ENOTCONN WSAENOTCONN
# define ESHUTDOWN WSAESHUTDOWN
# define ETOOMANYREFS WSAETOOMANYREFS
# undef ETIMEDOUT /* override definition in errno.h */
# define ETIMEDOUT WSAETIMEDOUT
# undef ECONNREFUSED /* override definition in errno.h */
# define ECONNREFUSED WSAECONNREFUSED
# undef ELOOP /* override definition in errno.h */
# define ELOOP WSAELOOP
# ifndef ENAMETOOLONG /* possible previous definition in errno.h */
# define ENAMETOOLONG WSAENAMETOOLONG
# endif
# define EHOSTDOWN WSAEHOSTDOWN
# undef EHOSTUNREACH /* override definition in errno.h */
# define EHOSTUNREACH WSAEHOSTUNREACH
# ifndef ENOTEMPTY /* possible previous definition in errno.h */
# define ENOTEMPTY WSAENOTEMPTY
# endif
# define EPROCLIM WSAEPROCLIM
# define EUSERS WSAEUSERS
# define EDQUOT WSAEDQUOT
# define ESTALE WSAESTALE
# define EREMOTE WSAEREMOTE
#endif
#ifndef HAVE_WRITEV
/* Structure for scatter/gather I/O. */
struct iovec {
@ -87,63 +175,200 @@ struct iovec {
};
#endif
/* Return 1 if the specified error number describes a readiness error, or 0
* otherwise. This is mostly for HP-UX, which could return EAGAIN or
* EWOULDBLOCK. See this man page
*
* http://devrsrc1.external.hp.com/STKS/cgi-bin/man2html?
* manpage=/usr/share/man/man2.Z/send.2
*/
ares_bool_t ares__socket_try_again(int errnum)
static ares_conn_err_t ares__socket_deref_error(int err)
{
#if !defined EWOULDBLOCK && !defined EAGAIN
# error "Neither EWOULDBLOCK nor EAGAIN defined"
switch (err) {
#if defined(EWOULDBLOCK)
case EWOULDBLOCK:
return ARES_CONN_ERR_WOULDBLOCK;
#endif
#if defined(EAGAIN) && (!defined(EWOULDBLOCK) || EAGAIN != EWOULDBLOCK)
case EAGAIN:
return ARES_CONN_ERR_WOULDBLOCK;
#endif
case EINPROGRESS:
return ARES_CONN_ERR_WOULDBLOCK;
case ENETDOWN:
return ARES_CONN_ERR_NETDOWN;
case ENETUNREACH:
return ARES_CONN_ERR_NETUNREACH;
case ECONNABORTED:
return ARES_CONN_ERR_CONNABORTED;
case ECONNRESET:
return ARES_CONN_ERR_CONNRESET;
case ECONNREFUSED:
return ARES_CONN_ERR_CONNREFUSED;
case ETIMEDOUT:
return ARES_CONN_ERR_CONNTIMEDOUT;
case EHOSTDOWN:
return ARES_CONN_ERR_HOSTDOWN;
case EHOSTUNREACH:
return ARES_CONN_ERR_HOSTUNREACH;
case EINTR:
return ARES_CONN_ERR_INTERRUPT;
case EAFNOSUPPORT:
return ARES_CONN_ERR_AFNOSUPPORT;
case EADDRNOTAVAIL:
return ARES_CONN_ERR_BADADDR;
default:
break;
}
#ifdef EWOULDBLOCK
if (errnum == EWOULDBLOCK) {
return ARES_TRUE;
return ARES_CONN_ERR_FAILURE;
}
static ares_bool_t same_address(const struct sockaddr *sa,
const struct ares_addr *aa)
{
const void *addr1;
const void *addr2;
if (sa->sa_family == aa->family) {
switch (aa->family) {
case AF_INET:
addr1 = &aa->addr.addr4;
addr2 = &(CARES_INADDR_CAST(const struct sockaddr_in *, sa))->sin_addr;
if (memcmp(addr1, addr2, sizeof(aa->addr.addr4)) == 0) {
return ARES_TRUE; /* match */
}
#endif
break;
case AF_INET6:
addr1 = &aa->addr.addr6;
addr2 =
&(CARES_INADDR_CAST(const struct sockaddr_in6 *, sa))->sin6_addr;
if (memcmp(addr1, addr2, sizeof(aa->addr.addr6)) == 0) {
return ARES_TRUE; /* match */
}
break;
default:
break; /* LCOV_EXCL_LINE */
}
}
return ARES_FALSE; /* different */
}
#if defined EAGAIN && EAGAIN != EWOULDBLOCK
if (errnum == EAGAIN) {
return ARES_TRUE;
void ares__conn_sock_state_cb_update(ares_conn_t *conn,
ares_conn_state_flags_t flags)
{
ares_channel_t *channel = conn->server->channel;
if ((conn->state_flags & ARES_CONN_STATE_CBFLAGS) != flags &&
channel->sock_state_cb) {
channel->sock_state_cb(channel->sock_state_cb_data, conn->fd,
flags & ARES_CONN_STATE_READ ? 1 : 0,
flags & ARES_CONN_STATE_WRITE ? 1 : 0);
}
#endif
return ARES_FALSE;
conn->state_flags &= ~((unsigned int)ARES_CONN_STATE_CBFLAGS);
conn->state_flags |= flags;
}
ares_ssize_t ares__socket_recv(ares_channel_t *channel, ares_socket_t s,
void *data, size_t data_len)
ares_conn_err_t ares__socket_recv(ares_channel_t *channel, ares_socket_t s,
ares_bool_t is_tcp, void *data,
size_t data_len, size_t *read_bytes)
{
ares_ssize_t rv;
*read_bytes = 0;
if (channel->sock_funcs && channel->sock_funcs->arecvfrom) {
return channel->sock_funcs->arecvfrom(s, data, data_len, 0, 0, 0,
rv = channel->sock_funcs->arecvfrom(s, data, data_len, 0, 0, 0,
channel->sock_func_cb_data);
} else {
rv = (ares_ssize_t)recv((RECV_TYPE_ARG1)s, (RECV_TYPE_ARG2)data,
(RECV_TYPE_ARG3)data_len, (RECV_TYPE_ARG4)(0));
}
return (ares_ssize_t)recv((RECV_TYPE_ARG1)s, (RECV_TYPE_ARG2)data,
(RECV_TYPE_ARG3)data_len, (RECV_TYPE_ARG4)(0));
if (rv > 0) {
*read_bytes = (size_t)rv;
return ARES_CONN_ERR_SUCCESS;
}
if (rv == 0) {
/* UDP allows 0-byte packets and is connectionless, so this is success */
if (!is_tcp) {
return ARES_CONN_ERR_SUCCESS;
} else {
return ARES_CONN_ERR_CONNCLOSED;
}
}
/* If we're here, rv<0 */
return ares__socket_deref_error(SOCKERRNO);
}
ares_ssize_t ares__socket_recvfrom(ares_channel_t *channel, ares_socket_t s,
void *data, size_t data_len, int flags,
ares_conn_err_t ares__socket_recvfrom(ares_channel_t *channel, ares_socket_t s,
ares_bool_t is_tcp, void *data,
size_t data_len, int flags,
struct sockaddr *from,
ares_socklen_t *from_len)
ares_socklen_t *from_len,
size_t *read_bytes)
{
ares_ssize_t rv;
if (channel->sock_funcs && channel->sock_funcs->arecvfrom) {
return channel->sock_funcs->arecvfrom(s, data, data_len, flags, from,
rv = channel->sock_funcs->arecvfrom(s, data, data_len, flags, from,
from_len, channel->sock_func_cb_data);
}
} else {
#ifdef HAVE_RECVFROM
return (ares_ssize_t)recvfrom(s, data, (RECVFROM_TYPE_ARG3)data_len, flags,
rv = (ares_ssize_t)recvfrom(s, data, (RECVFROM_TYPE_ARG3)data_len, flags,
from, from_len);
#else
return ares__socket_recv(channel, s, data, data_len);
return ares__socket_recv(channel, s, is_udp, data, data_len);
#endif
}
if (rv > 0) {
*read_bytes = (size_t)rv;
return ARES_CONN_ERR_SUCCESS;
}
if (rv == 0) {
/* UDP allows 0-byte packets and is connectionless, so this is success */
if (!is_tcp) {
return ARES_CONN_ERR_SUCCESS;
} else {
return ARES_CONN_ERR_CONNCLOSED;
}
}
/* If we're here, rv<0 */
return ares__socket_deref_error(SOCKERRNO);
}
ares_conn_err_t ares__conn_read(ares_conn_t *conn, void *data, size_t len,
size_t *read_bytes)
{
ares_channel_t *channel = conn->server->channel;
ares_conn_err_t err;
if (!(conn->flags & ARES_CONN_FLAG_TCP)) {
struct sockaddr_storage sa_storage;
ares_socklen_t salen = sizeof(sa_storage);
memset(&sa_storage, 0, sizeof(sa_storage));
err =
ares__socket_recvfrom(channel, conn->fd, ARES_FALSE, data, len, 0,
(struct sockaddr *)&sa_storage, &salen, read_bytes);
#ifdef HAVE_RECVFROM
if (err == ARES_CONN_ERR_SUCCESS &&
!same_address((struct sockaddr *)&sa_storage, &conn->server->addr)) {
err = ARES_CONN_ERR_WOULDBLOCK;
}
#endif
} else {
err =
ares__socket_recv(channel, conn->fd, ARES_TRUE, data, len, read_bytes);
}
/* Toggle connected state if needed */
if (err == ARES_CONN_ERR_SUCCESS) {
conn->state_flags |= ARES_CONN_STATE_CONNECTED;
}
return err;
}
/* Use like:
@ -230,10 +455,23 @@ static ares_status_t ares_conn_set_self_ip(ares_conn_t *conn, ares_bool_t early)
return ARES_SUCCESS;
}
ares_ssize_t ares__conn_write(ares_conn_t *conn, const void *data, size_t len)
ares_conn_err_t ares__conn_write(ares_conn_t *conn, const void *data,
size_t len, size_t *written)
{
ares_channel_t *channel = conn->server->channel;
int flags = 0;
ares_ssize_t rv;
ares_bool_t is_tfo = ARES_FALSE;
ares_conn_err_t err = ARES_CONN_ERR_SUCCESS;
*written = 0;
/* Don't try to write if not doing initial TFO and not connected */
if (conn->flags & ARES_CONN_FLAG_TCP &&
!(conn->state_flags & ARES_CONN_STATE_CONNECTED) &&
!(conn->flags & ARES_CONN_FLAG_TFO_INITIAL)) {
return ARES_CONN_ERR_WOULDBLOCK;
}
#ifdef HAVE_MSG_NOSIGNAL
flags |= MSG_NOSIGNAL;
@ -243,41 +481,162 @@ ares_ssize_t ares__conn_write(ares_conn_t *conn, const void *data, size_t len)
struct iovec vec;
vec.iov_base = (void *)((size_t)data); /* Cast off const */
vec.iov_len = len;
return channel->sock_funcs->asendv(conn->fd, &vec, 1,
rv = channel->sock_funcs->asendv(conn->fd, &vec, 1,
channel->sock_func_cb_data);
if (rv <= 0) {
err = ares__socket_deref_error(SOCKERRNO);
} else {
*written = (size_t)rv;
}
goto done;
}
if (conn->flags & ARES_CONN_FLAG_TFO_INITIAL) {
conn->flags &= ~((unsigned int)ARES_CONN_FLAG_TFO_INITIAL);
is_tfo = ARES_TRUE;
#if defined(TFO_USE_SENDTO) && TFO_USE_SENDTO
{
struct sockaddr_storage sa_storage;
ares_socklen_t salen = sizeof(sa_storage);
struct sockaddr *sa = (struct sockaddr *)&sa_storage;
ares_status_t status;
ares_ssize_t rv;
status = ares__conn_set_sockaddr(conn, sa, &salen);
if (status != ARES_SUCCESS) {
return status;
if (ares__conn_set_sockaddr(conn, sa, &salen) != ARES_SUCCESS) {
return ARES_CONN_ERR_FAILURE;
}
rv = (ares_ssize_t)sendto((SEND_TYPE_ARG1)conn->fd, (SEND_TYPE_ARG2)data,
(SEND_TYPE_ARG3)len, (SEND_TYPE_ARG4)flags, sa,
salen);
if (rv <= 0) {
err = ares__socket_deref_error(SOCKERRNO);
} else {
*written = (size_t)rv;
}
/* If using TFO, we might not have been able to get an IP earlier, since
* we hadn't informed the OS of the destination. When using sendto()
* now we have so we should be able to fetch it */
ares_conn_set_self_ip(conn, ARES_TRUE);
return rv;
ares_conn_set_self_ip(conn, ARES_FALSE);
goto done;
}
#endif
}
return (ares_ssize_t)send((SEND_TYPE_ARG1)conn->fd, (SEND_TYPE_ARG2)data,
rv = (ares_ssize_t)send((SEND_TYPE_ARG1)conn->fd, (SEND_TYPE_ARG2)data,
(SEND_TYPE_ARG3)len, (SEND_TYPE_ARG4)flags);
if (rv <= 0) {
err = ares__socket_deref_error(SOCKERRNO);
} else {
*written = (size_t)rv;
}
goto done;
done:
if (err == ARES_CONN_ERR_SUCCESS && len == *written) {
/* Wrote all data, make sure we're not listening for write events unless
* using TFO, in which case we'll need a write event to know when
* we're connected. */
ares__conn_sock_state_cb_update(
conn, ARES_CONN_STATE_READ |
(is_tfo ? ARES_CONN_STATE_WRITE : ARES_CONN_STATE_NONE));
} else if (err == ARES_CONN_ERR_WOULDBLOCK) {
/* Need to wait on more buffer space to write */
ares__conn_sock_state_cb_update(conn, ARES_CONN_STATE_READ |
ARES_CONN_STATE_WRITE);
}
return err;
}
ares_status_t ares__conn_flush(ares_conn_t *conn)
{
const unsigned char *data;
size_t data_len;
size_t count;
ares_conn_err_t err;
ares_status_t status;
ares_bool_t tfo = ARES_FALSE;
if (conn == NULL) {
return ARES_EFORMERR;
}
if (conn->flags & ARES_CONN_FLAG_TFO_INITIAL) {
tfo = ARES_TRUE;
}
do {
if (ares__buf_len(conn->out_buf) == 0) {
status = ARES_SUCCESS;
goto done;
}
if (conn->flags & ARES_CONN_FLAG_TCP) {
data = ares__buf_peek(conn->out_buf, &data_len);
} else {
unsigned short msg_len;
/* Read length, then provide buffer without length */
ares__buf_tag(conn->out_buf);
status = ares__buf_fetch_be16(conn->out_buf, &msg_len);
if (status != ARES_SUCCESS) {
return status;
}
ares__buf_tag_rollback(conn->out_buf);
data = ares__buf_peek(conn->out_buf, &data_len);
if (data_len < msg_len + 2) {
status = ARES_EFORMERR;
goto done;
}
data += 2;
data_len = msg_len;
}
err = ares__conn_write(conn, data, data_len, &count);
if (err != ARES_CONN_ERR_SUCCESS) {
if (err != ARES_CONN_ERR_WOULDBLOCK) {
status = ARES_ECONNREFUSED;
goto done;
}
status = ARES_SUCCESS;
goto done;
}
/* UDP didn't send the length prefix so augment that here */
if (!(conn->flags & ARES_CONN_FLAG_TCP)) {
count += 2;
}
/* Strip data written from the buffer */
ares__buf_consume(conn->out_buf, (size_t)count);
status = ARES_SUCCESS;
/* Loop only for UDP since we have to send per-packet. We already
* sent everything we could if using tcp */
} while (!(conn->flags & ARES_CONN_FLAG_TCP));
done:
if (status == ARES_SUCCESS) {
ares_conn_state_flags_t flags = ARES_CONN_STATE_READ;
/* When using TFO, the we need to enabling waiting on a write event to
* be notified of when a connection is actually established */
if (tfo) {
flags |= ARES_CONN_STATE_WRITE;
}
/* If using TCP and not all data was written (partial write), that means
* we need to also wait on a write event */
if (conn->flags & ARES_CONN_FLAG_TCP && ares__buf_len(conn->out_buf)) {
flags |= ARES_CONN_STATE_WRITE;
}
ares__conn_sock_state_cb_update(conn, flags);
}
return status;
}
/*
@ -516,10 +875,11 @@ static ares_status_t ares__conn_connect(ares_conn_t *conn, struct sockaddr *sa,
#elif defined(TFO_USE_CONNECTX) && TFO_USE_CONNECTX
{
int rv;
int err;
ares_conn_err_t err;
do {
sa_endpoints_t endpoints;
memset(&endpoints, 0, sizeof(endpoints));
endpoints.sae_dstaddr = sa;
endpoints.sae_dstaddrlen = salen;
@ -528,12 +888,16 @@ static ares_status_t ares__conn_connect(ares_conn_t *conn, struct sockaddr *sa,
CONNECT_DATA_IDEMPOTENT | CONNECT_RESUME_ON_READ_WRITE,
NULL, 0, NULL, NULL);
err = SOCKERRNO;
if (rv == -1 && err != EINPROGRESS && err != EWOULDBLOCK) {
return ARES_ECONNREFUSED;
if (rv < 0) {
err = ares__socket_deref_error(SOCKERRNO);
} else {
break;
}
} while (rv == -1 && err == EINTR);
if (err != ARES_CONN_ERR_WOULDBLOCK && err != ARES_CONN_ERR_INTERRUPT) {
return ARES_ECONNREFUSED;
}
} while (err == ARES_CONN_ERR_INTERRUPT);
}
return ARES_SUCCESS;
#elif defined(TFO_SUPPORTED) && TFO_SUPPORTED
@ -555,6 +919,7 @@ ares_status_t ares__open_connection(ares_conn_t **conn_out,
ares_conn_t *conn;
ares__llist_node_t *node = NULL;
int stype = is_tcp ? SOCK_STREAM : SOCK_DGRAM;
ares_conn_state_flags_t state_flags;
*conn_out = NULL;
@ -568,6 +933,16 @@ ares_status_t ares__open_connection(ares_conn_t **conn_out,
conn->server = server;
conn->queries_to_conn = ares__llist_create(NULL);
conn->flags = is_tcp ? ARES_CONN_FLAG_TCP : ARES_CONN_FLAG_NONE;
conn->out_buf = ares__buf_create();
conn->in_buf = ares__buf_create();
if (conn->queries_to_conn == NULL || conn->out_buf == NULL ||
conn->in_buf == NULL) {
/* LCOV_EXCL_START: OutOfMemory */
status = ARES_ENOMEM;
goto done;
/* LCOV_EXCL_STOP */
}
/* Enable TFO if the OS supports it and we were passed in data to send during
* the connect. It might be disabled later if an error is encountered. Make
@ -577,13 +952,6 @@ ares_status_t ares__open_connection(ares_conn_t **conn_out,
conn->flags |= ARES_CONN_FLAG_TFO;
}
if (conn->queries_to_conn == NULL) {
/* LCOV_EXCL_START: OutOfMemory */
status = ARES_ENOMEM;
goto done;
/* LCOV_EXCL_STOP */
}
/* Convert into the struct sockaddr structure needed by the OS */
status = ares__conn_set_sockaddr(conn, sa, &salen);
if (status != ARES_SUCCESS) {
@ -591,8 +959,8 @@ ares_status_t ares__open_connection(ares_conn_t **conn_out,
}
/* Acquire a socket. */
conn->fd = ares__open_socket(channel, server->addr.family, stype, 0);
if (conn->fd == ARES_SOCKET_BAD) {
if (ares__open_socket(&conn->fd, channel, server->addr.family, stype, 0) !=
ARES_CONN_ERR_SUCCESS) {
status = ARES_ECONNREFUSED;
goto done;
}
@ -633,7 +1001,7 @@ ares_status_t ares__open_connection(ares_conn_t **conn_out,
}
/* Need to store our own ip for DNS cookie support */
status = ares_conn_set_self_ip(conn, ARES_FALSE);
status = ares_conn_set_self_ip(conn, ARES_TRUE);
if (status != ARES_SUCCESS) {
goto done; /* LCOV_EXCL_LINE: UntestablePath */
}
@ -662,7 +1030,20 @@ ares_status_t ares__open_connection(ares_conn_t **conn_out,
/* LCOV_EXCL_STOP */
}
SOCK_STATE_CALLBACK(channel, conn->fd, 1, is_tcp ? 1 : 0);
state_flags = ARES_CONN_STATE_READ;
/* Get notified on connect if using TCP */
if (conn->flags & ARES_CONN_FLAG_TCP) {
state_flags |= ARES_CONN_STATE_WRITE;
}
/* Dot no attempt to update sock state callbacks on TFO until *after* the
* initial write is performed. Due to the notification event, its possible
* an erroneous read can come in before the attempt to write the data which
* might be used to set the ip address */
if (!(conn->flags & ARES_CONN_FLAG_TFO_INITIAL)) {
ares__conn_sock_state_cb_update(conn, state_flags);
}
if (is_tcp) {
server->tcp_conn = conn;
@ -673,6 +1054,8 @@ done:
ares__llist_node_claim(node);
ares__llist_destroy(conn->queries_to_conn);
ares__close_socket(channel, conn->fd);
ares__buf_destroy(conn->out_buf);
ares__buf_destroy(conn->in_buf);
ares_free(conn);
} else {
*conn_out = conn;
@ -680,15 +1063,27 @@ done:
return status;
}
ares_socket_t ares__open_socket(ares_channel_t *channel, int af, int type,
int protocol)
ares_conn_err_t ares__open_socket(ares_socket_t *sock, ares_channel_t *channel,
int af, int type, int protocol)
{
ares_socket_t s;
*sock = ARES_SOCKET_BAD;
if (channel->sock_funcs && channel->sock_funcs->asocket) {
return channel->sock_funcs->asocket(af, type, protocol,
s = channel->sock_funcs->asocket(af, type, protocol,
channel->sock_func_cb_data);
} else {
s = socket(af, type, protocol);
}
if (s == ARES_SOCKET_BAD) {
return ares__socket_deref_error(SOCKERRNO);
}
return socket(af, type, protocol);
*sock = s;
return ARES_CONN_ERR_SUCCESS;
}
ares_status_t ares__connect_socket(ares_channel_t *channel,
@ -697,7 +1092,7 @@ ares_status_t ares__connect_socket(ares_channel_t *channel,
ares_socklen_t addrlen)
{
int rv;
int err;
ares_conn_err_t err;
do {
if (channel->sock_funcs && channel->sock_funcs->aconnect) {
@ -707,13 +1102,16 @@ ares_status_t ares__connect_socket(ares_channel_t *channel,
rv = connect(sockfd, addr, addrlen);
}
err = SOCKERRNO;
if (rv < 0) {
err = ares__socket_deref_error(SOCKERRNO);
} else {
break;
}
if (rv == -1 && err != EINPROGRESS && err != EWOULDBLOCK) {
if (err != ARES_CONN_ERR_WOULDBLOCK && err != ARES_CONN_ERR_INTERRUPT) {
return ARES_ECONNREFUSED;
}
} while (rv == -1 && err == EINTR);
} while (err == ARES_CONN_ERR_INTERRUPT);
return ARES_SUCCESS;
}
@ -762,3 +1160,14 @@ void ares_set_socket_functions(ares_channel_t *channel,
channel->sock_funcs = funcs;
channel->sock_func_cb_data = data;
}
void ares_set_notify_pending_write_callback(
ares_channel_t *channel, ares_notify_pending_write_callback callback,
void *user_data)
{
if (channel == NULL || channel->optmask & ARES_OPT_EVENT_THREAD) {
return;
}
channel->notify_pending_write_cb = callback;
channel->notify_pending_write_cb_data = user_data;
}

10
src/lib/ares__sortaddrinfo.c
Unescape View File

@ -347,6 +347,7 @@ static int find_src_addr(ares_channel_t *channel, const struct sockaddr *addr,
{
ares_socket_t sock;
ares_socklen_t len;
ares_conn_err_t err;
switch (addr->sa_family) {
case AF_INET:
@ -360,14 +361,13 @@ static int find_src_addr(ares_channel_t *channel, const struct sockaddr *addr,
return 0;
}
sock = ares__open_socket(channel, addr->sa_family, SOCK_DGRAM, IPPROTO_UDP);
if (sock == ARES_SOCKET_BAD) {
if (SOCKERRNO == EAFNOSUPPORT) {
err =
ares__open_socket(&sock, channel, addr->sa_family, SOCK_DGRAM, IPPROTO_UDP);
if (err == ARES_CONN_ERR_AFNOSUPPORT) {
return 0;
} else {
} else if (err != ARES_CONN_ERR_SUCCESS) {
return -1;
}
}
if (ares__connect_socket(channel, sock, addr, len) != ARES_SUCCESS) {
ares__close_socket(channel, sock);

2
src/lib/ares_destroy.c
Unescape View File

@ -142,8 +142,6 @@ void ares__destroy_server(ares_server_t *server)
ares__close_sockets(server);
ares__llist_destroy(server->connections);
ares__buf_destroy(server->tcp_parser);
ares__buf_destroy(server->tcp_send);
ares_free(server);
}

4
src/lib/ares_inet_net_pton.h
Unescape View File

@ -26,10 +26,6 @@
#ifndef HEADER_CARES_INET_NET_PTON_H
#define HEADER_CARES_INET_NET_PTON_H
#ifdef HAVE_INET_NET_PTON
# define ares_inet_net_pton(w, x, y, z) inet_net_pton(w, x, y, z)
#else
int ares_inet_net_pton(int af, const char *src, void *dst, size_t size);
#endif
#endif /* HEADER_CARES_INET_NET_PTON_H */

32
src/lib/ares_init.c
Unescape View File

@ -171,15 +171,6 @@ static ares_status_t init_by_defaults(ares_channel_t *channel)
}
}
#if defined(USE_WINSOCK)
# define toolong(x) (x == -1) && (SOCKERRNO == WSAEFAULT)
#elif defined(ENAMETOOLONG)
# define toolong(x) \
(x == -1) && ((SOCKERRNO == ENAMETOOLONG) || (SOCKERRNO == EINVAL))
#else
# define toolong(x) (x == -1) && (SOCKERRNO == EINVAL)
#endif
if (channel->ndomains == 0) {
/* Derive a default domain search list from the kernel hostname,
* or set it to empty if the hostname isn't helpful.
@ -187,9 +178,7 @@ static ares_status_t init_by_defaults(ares_channel_t *channel)
#ifndef HAVE_GETHOSTNAME
channel->ndomains = 0; /* default to none */
#else
GETHOSTNAME_TYPE_ARG2 lenv = 64;
size_t len = 64;
int res;
size_t len = 256;
channel->ndomains = 0; /* default to none */
hostname = ares_malloc(len);
@ -198,29 +187,12 @@ static ares_status_t init_by_defaults(ares_channel_t *channel)
goto error; /* LCOV_EXCL_LINE: OutOfMemory */
}
do {
res = gethostname(hostname, lenv);
if (toolong(res)) {
char *p;
len *= 2;
lenv *= 2;
p = ares_realloc(hostname, len);
if (!p) {
rc = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */
goto error; /* LCOV_EXCL_LINE: OutOfMemory */
}
hostname = p;
continue;
} else if (res) {
if (gethostname(hostname, (GETHOSTNAME_TYPE_ARG2)len) != 0) {
/* Lets not treat a gethostname failure as critical, since we
* are ok if gethostname doesn't even exist */
*hostname = '\0';
break;
}
} while (res != 0);
dot = strchr(hostname, '.');
if (dot) {
/* a dot was found */

87
src/lib/ares_private.h
Unescape View File

@ -172,13 +172,36 @@ typedef enum {
ARES_CONN_FLAG_TFO_INITIAL = 1 << 2
} ares_conn_flags_t;
typedef enum {
ARES_CONN_STATE_NONE = 0,
ARES_CONN_STATE_READ = 1 << 0,
ARES_CONN_STATE_WRITE = 1 << 1,
ARES_CONN_STATE_CONNECTED = 1 << 2, /* This doesn't get a callback */
ARES_CONN_STATE_CBFLAGS = ARES_CONN_STATE_READ | ARES_CONN_STATE_WRITE
} ares_conn_state_flags_t;
struct ares_conn {
ares_server_t *server;
ares_socket_t fd;
struct ares_addr self_ip;
ares_conn_flags_t flags;
ares_conn_state_flags_t state_flags;
/*! Outbound buffered data that is not yet sent. Exists as one contiguous
* stream in TCP format (big endian 16bit length prefix followed by DNS
* wire-format message). For TCP this can be sent as-is, UDP this must
* be sent per-packet (stripping the length prefix) */
ares__buf_t *out_buf;
/*! Inbound buffered data that is not yet parsed. Exists as one contiguous
* stream in TCP format (big endian 16bit length prefix followed by DNS
* wire-format message). TCP may have partial data and this needs to be
* handled gracefully, but UDP will always have a full message */
ares__buf_t *in_buf;
/* total number of queries run on this connection since it was established */
size_t total_queries;
/* list of outstanding queries to this connection */
ares__llist_t *queries_to_conn;
};
@ -271,13 +294,6 @@ struct ares_server {
/* The next time when we will retry this server if it has hit failures */
ares_timeval_t next_retry_time;
/* TCP buffer since multiple responses can come back in one read, or partial
* in a read */
ares__buf_t *tcp_parser;
/* TCP output queue */
ares__buf_t *tcp_send;
/*! Buckets for collecting metrics about the server */
ares_server_metrics_t metrics[ARES_METRIC_COUNT];
@ -403,6 +419,10 @@ struct ares_channeldata {
const struct ares_socket_functions *sock_funcs;
void *sock_func_cb_data;
ares_notify_pending_write_callback notify_pending_write_cb;
void *notify_pending_write_cb_data;
ares_bool_t notify_pending_write;
/* Path for resolv.conf file, configurable via ares_options */
char *resolvconf_path;
@ -609,16 +629,45 @@ ares_status_t ares__open_connection(ares_conn_t **conn_out,
ares_bool_t ares_sockaddr_to_ares_addr(struct ares_addr *ares_addr,
unsigned short *port,
const struct sockaddr *sockaddr);
ares_socket_t ares__open_socket(ares_channel_t *channel, int af, int type,
int protocol);
/*! Socket errors */
typedef enum {
ARES_CONN_ERR_SUCCESS = 0, /*!< Success */
ARES_CONN_ERR_WOULDBLOCK = 1, /*!< Operation would block */
ARES_CONN_ERR_CONNCLOSED = 2, /*!< Connection closed (gracefully) */
ARES_CONN_ERR_CONNABORTED = 3, /*!< Connection Aborted */
ARES_CONN_ERR_CONNRESET = 4, /*!< Connection Reset */
ARES_CONN_ERR_CONNREFUSED = 5, /*!< Connection Refused */
ARES_CONN_ERR_CONNTIMEDOUT = 6, /*!< Connection Timed Out */
ARES_CONN_ERR_HOSTDOWN = 7, /*!< Host Down */
ARES_CONN_ERR_HOSTUNREACH = 8, /*!< Host Unreachable */
ARES_CONN_ERR_NETDOWN = 9, /*!< Network Down */
ARES_CONN_ERR_NETUNREACH = 10, /*!< Network Unreachable */
ARES_CONN_ERR_INTERRUPT = 11, /*!< Call interrupted by signal, repeat */
ARES_CONN_ERR_AFNOSUPPORT = 12, /*!< Address family not supported */
ARES_CONN_ERR_BADADDR = 13, /*!< Bad Address / Unavailable */
ARES_CONN_ERR_FAILURE = 99 /*!< Generic failure */
} ares_conn_err_t;
ares_conn_err_t ares__open_socket(ares_socket_t *sock, ares_channel_t *channel,
int af, int type, int protocol);
ares_bool_t ares__socket_try_again(int errnum);
ares_ssize_t ares__conn_write(ares_conn_t *conn, const void *data, size_t len);
ares_ssize_t ares__socket_recvfrom(ares_channel_t *channel, ares_socket_t s,
void *data, size_t data_len, int flags,
ares_conn_err_t ares__conn_write(ares_conn_t *conn, const void *data,
size_t len, size_t *written);
ares_status_t ares__conn_flush(ares_conn_t *conn);
ares_conn_err_t ares__conn_read(ares_conn_t *conn, void *data, size_t len,
size_t *read_bytes);
void ares__conn_sock_state_cb_update(ares_conn_t *conn,
ares_conn_state_flags_t flags);
ares_conn_err_t ares__socket_recv(ares_channel_t *channel, ares_socket_t s,
ares_bool_t is_tcp, void *data,
size_t data_len, size_t *read_bytes);
ares_conn_err_t ares__socket_recvfrom(ares_channel_t *channel, ares_socket_t s,
ares_bool_t is_tcp, void *data,
size_t data_len, int flags,
struct sockaddr *from,
ares_socklen_t *from_len);
ares_ssize_t ares__socket_recv(ares_channel_t *channel, ares_socket_t s,
void *data, size_t data_len);
ares_socklen_t *from_len,
size_t *read_bytes);
void ares__close_socket(ares_channel_t *channel, ares_socket_t s);
ares_status_t ares__connect_socket(ares_channel_t *channel,
ares_socket_t sockfd,
@ -730,14 +779,6 @@ ares_status_t ares__dns_name_write(ares__buf_t *buf, ares__llist_t **list,
*/
void ares_queue_notify_empty(ares_channel_t *channel);
#define SOCK_STATE_CALLBACK(c, s, r, w) \
do { \
if ((c)->sock_state_cb) { \
(c)->sock_state_cb((c)->sock_state_cb_data, (s), (r), (w)); \
} \
} while (0)
#define ARES_CONFIG_CHECK(x) \
(x && x->lookups && ares__slist_len(x->servers) > 0 && x->timeout > 0 && \
x->tries > 0)

500
src/lib/ares_process.c
Unescape View File

@ -46,23 +46,20 @@
static void timeadd(ares_timeval_t *now, size_t millisecs);
static void write_tcp_data(ares_channel_t *channel, fd_set *write_fds,
static void process_write(ares_channel_t *channel, fd_set *write_fds,
ares_socket_t write_fd);
static void read_packets(ares_channel_t *channel, fd_set *read_fds,
static void process_read(ares_channel_t *channel, fd_set *read_fds,
ares_socket_t read_fd, const ares_timeval_t *now);
static void process_timeouts(ares_channel_t *channel,
const ares_timeval_t *now);
static ares_status_t process_answer(ares_channel_t *channel,
const unsigned char *abuf, size_t alen,
ares_conn_t *conn, ares_bool_t tcp,
ares_conn_t *conn,
const ares_timeval_t *now);
static void handle_conn_error(ares_conn_t *conn, ares_bool_t critical_failure,
ares_status_t failure_status);
static ares_bool_t same_questions(const ares_query_t *query,
const ares_dns_record_t *arec);
static ares_bool_t same_address(const struct sockaddr *sa,
const struct ares_addr *aa);
static void end_query(ares_channel_t *channel, ares_server_t *server,
ares_query_t *query, ares_status_t status,
const ares_dns_record_t *dnsrec);
@ -204,12 +201,10 @@ static void processfds(ares_channel_t *channel, fd_set *read_fds,
}
ares__channel_lock(channel);
ares__tvnow(&now);
read_packets(channel, read_fds, read_fd, &now);
process_read(channel, read_fds, read_fd, &now);
process_timeouts(channel, &now);
/* Write last as the other 2 operations might have triggered writes */
write_tcp_data(channel, write_fds, write_fd);
process_write(channel, write_fds, write_fd);
/* See if any connections should be cleaned up */
ares__check_cleanup_conns(channel);
@ -235,105 +230,233 @@ void ares_process_fd(ares_channel_t *channel,
processfds(channel, NULL, read_fd, NULL, write_fd);
}
static ares_socket_t *channel_socket_list(const ares_channel_t *channel,
size_t *num)
{
ares__slist_node_t *snode;
ares__array_t *arr = ares__array_create(sizeof(ares_socket_t), NULL);
*num = 0;
if (arr == NULL) {
return NULL; /* LCOV_EXCL_LINE: OutOfMemory */
}
for (snode = ares__slist_node_first(channel->servers); snode != NULL;
snode = ares__slist_node_next(snode)) {
ares_server_t *server = ares__slist_node_val(snode);
ares__llist_node_t *node;
for (node = ares__llist_node_first(server->connections); node != NULL;
node = ares__llist_node_next(node)) {
const ares_conn_t *conn = ares__llist_node_val(node);
ares_socket_t *sptr;
ares_status_t status;
if (conn->fd == ARES_SOCKET_BAD) {
continue;
}
status = ares__array_insert_last((void **)&sptr, arr);
if (status != ARES_SUCCESS) {
ares__array_destroy(arr); /* LCOV_EXCL_LINE: OutOfMemory */
return NULL; /* LCOV_EXCL_LINE: OutOfMemory */
}
*sptr = conn->fd;
}
}
return ares__array_finish(arr, num);
}
/* If any TCP sockets select true for writing, write out queued data
* we have for them.
*/
static void write_tcp_data(ares_channel_t *channel, fd_set *write_fds,
static void ares_notify_write(ares_conn_t *conn)
{
ares_status_t status;
/* Mark as connected if we got here and TFO Initial not set */
if (!(conn->flags & ARES_CONN_FLAG_TFO_INITIAL)) {
conn->state_flags |= ARES_CONN_STATE_CONNECTED;
}
status = ares__conn_flush(conn);
if (status != ARES_SUCCESS) {
handle_conn_error(conn, ARES_TRUE, status);
}
}
static void process_write(ares_channel_t *channel, fd_set *write_fds,
ares_socket_t write_fd)
{
ares__slist_node_t *node;
size_t i;
ares_socket_t *socketlist = NULL;
size_t num_sockets = 0;
ares__llist_node_t *node = NULL;
if (!write_fds && (write_fd == ARES_SOCKET_BAD)) {
if (!write_fds && write_fd == ARES_SOCKET_BAD) {
/* no possible action */
return;
}
for (node = ares__slist_node_first(channel->servers); node != NULL;
node = ares__slist_node_next(node)) {
ares_server_t *server = ares__slist_node_val(node);
const unsigned char *data;
size_t data_len;
ares_ssize_t count;
/* Make sure server has data to send and is selected in write_fds or
write_fd. */
if (ares__buf_len(server->tcp_send) == 0 || server->tcp_conn == NULL) {
continue;
/* Single socket specified */
if (!write_fds) {
node = ares__htable_asvp_get_direct(channel->connnode_by_socket, write_fd);
if (node == NULL) {
return;
}
if (write_fds) {
if (!FD_ISSET(server->tcp_conn->fd, write_fds)) {
continue;
ares_notify_write(ares__llist_node_val(node));
return;
}
} else {
if (server->tcp_conn->fd != write_fd) {
/* There is no good way to iterate across an fd_set, instead we must pull a
* list of all known fds, and iterate across that checking against the fd_set.
*/
socketlist = channel_socket_list(channel, &num_sockets);
for (i = 0; i < num_sockets; i++) {
if (!FD_ISSET(socketlist[i], write_fds)) {
continue;
}
}
if (write_fds) {
/* If there's an error and we close this socket, then open
* another with the same fd to talk to another server, then we
* don't want to think that it was the new socket that was
* ready. This is not disastrous, but is likely to result in
* extra system calls and confusion. */
FD_CLR(server->tcp_conn->fd, write_fds);
FD_CLR(socketlist[i], write_fds);
node =
ares__htable_asvp_get_direct(channel->connnode_by_socket, socketlist[i]);
if (node == NULL) {
return;
}
data = ares__buf_peek(server->tcp_send, &data_len);
count = ares__conn_write(server->tcp_conn, data, data_len);
if (count <= 0) {
if (!ares__socket_try_again(SOCKERRNO)) {
handle_conn_error(server->tcp_conn, ARES_TRUE, ARES_ECONNREFUSED);
ares_notify_write(ares__llist_node_val(node));
}
continue;
ares_free(socketlist);
}
void ares_process_pending_write(ares_channel_t *channel)
{
ares__slist_node_t *node;
if (channel == NULL) {
return;
}
/* Strip data written from the buffer */
ares__buf_consume(server->tcp_send, (size_t)count);
ares__channel_lock(channel);
if (!channel->notify_pending_write) {
ares__channel_unlock(channel);
return;
}
/* Notify state callback all data is written */
if (ares__buf_len(server->tcp_send) == 0) {
SOCK_STATE_CALLBACK(channel, server->tcp_conn->fd, 1, 0);
/* Set as untriggerd before calling into ares__conn_flush(), this is
* because its possible ares__conn_flush() might cause additional data to
* be enqueued if there is some form of exception so it will need to recurse.
*/
channel->notify_pending_write = ARES_FALSE;
for (node = ares__slist_node_first(channel->servers); node != NULL;
node = ares__slist_node_next(node)) {
ares_server_t *server = ares__slist_node_val(node);
ares_conn_t *conn = server->tcp_conn;
ares_status_t status;
if (conn == NULL) {
continue;
}
/* Enqueue any pending data if there is any */
status = ares__conn_flush(conn);
if (status != ARES_SUCCESS) {
handle_conn_error(conn, ARES_TRUE, status);
}
}
ares__channel_unlock(channel);
}
/* If any TCP socket selects true for reading, read some data,
* allocate a buffer if we finish reading the length word, and process
* a packet if we finish reading one.
*/
static void read_tcp_data(ares_channel_t *channel, ares_conn_t *conn,
const ares_timeval_t *now)
static ares_status_t read_conn_packets(ares_conn_t *conn)
{
ares_ssize_t count;
ares_server_t *server = conn->server;
ares_bool_t read_again;
ares_conn_err_t err;
ares_channel_t *channel = conn->server->channel;
/* Fetch buffer to store data we are reading */
size_t ptr_len = 65535;
do {
size_t count;
size_t len = 65535;
unsigned char *ptr;
size_t start_len = ares__buf_len(conn->in_buf);
/* If UDP, lets write out a placeholder for the length indicator */
if (!(conn->flags & ARES_CONN_FLAG_TCP)) {
if (ares__buf_append_be16(conn->in_buf, 0) != ARES_SUCCESS) {
handle_conn_error(conn, ARES_FALSE /* not critical to connection */,
ARES_SUCCESS);
return ARES_ENOMEM;
}
}
ptr = ares__buf_append_start(server->tcp_parser, &ptr_len);
/* Get a buffer of sufficient size */
ptr = ares__buf_append_start(conn->in_buf, &len);
if (ptr == NULL) {
handle_conn_error(conn, ARES_FALSE /* not critical to connection */,
ARES_SUCCESS);
return; /* bail out on malloc failure. TODO: make this
function return error codes */
return ARES_ENOMEM;
}
/* Read from socket */
count = ares__socket_recv(channel, conn->fd, ptr, ptr_len);
if (count <= 0) {
ares__buf_append_finish(server->tcp_parser, 0);
if (!(count == -1 && ares__socket_try_again(SOCKERRNO))) {
handle_conn_error(conn, ARES_TRUE, ARES_ECONNREFUSED);
err = ares__conn_read(conn, ptr, len, &count);
if (err != ARES_CONN_ERR_SUCCESS) {
ares__buf_append_finish(conn->in_buf, 0);
if (!(conn->flags & ARES_CONN_FLAG_TCP)) {
ares__buf_set_length(conn->in_buf, start_len);
}
return;
break;
}
/* Record amount of data read */
ares__buf_append_finish(server->tcp_parser, (size_t)count);
ares__buf_append_finish(conn->in_buf, (size_t)count);
/* Only loop if we're not overwriting socket functions, and are using UDP
* or are using TCP and read the maximum buffer size */
read_again = ARES_FALSE;
if (channel->sock_funcs == NULL) {
if (!(conn->flags & ARES_CONN_FLAG_TCP)) {
read_again = ARES_TRUE;
} else if (count == len) {
read_again = ARES_TRUE;
}
}
/* If UDP, overwrite length */
if (!(conn->flags & ARES_CONN_FLAG_TCP)) {
len = ares__buf_len(conn->in_buf);
ares__buf_set_length(conn->in_buf, start_len);
ares__buf_append_be16(conn->in_buf, (unsigned short)count);
ares__buf_set_length(conn->in_buf, len);
}
/* Try to read again only if *we* set up the socket, otherwise it may be
* a blocking socket and would cause recvfrom to hang. */
} while (read_again);
if (err != ARES_CONN_ERR_SUCCESS && err != ARES_CONN_ERR_WOULDBLOCK) {
handle_conn_error(conn, ARES_TRUE, ARES_ECONNREFUSED);
return ARES_ECONNREFUSED;
}
return ARES_SUCCESS;
}
static void read_answers(ares_conn_t *conn, const ares_timeval_t *now)
{
ares_channel_t *channel = conn->server->channel;
/* Process all queued answers */
while (1) {
@ -343,24 +466,24 @@ static void read_tcp_data(ares_channel_t *channel, ares_conn_t *conn,
ares_status_t status;
/* Tag so we can roll back */
ares__buf_tag(server->tcp_parser);
ares__buf_tag(conn->in_buf);
/* Read length indicator */
if (ares__buf_fetch_be16(server->tcp_parser, &dns_len) != ARES_SUCCESS) {
ares__buf_tag_rollback(server->tcp_parser);
if (ares__buf_fetch_be16(conn->in_buf, &dns_len) != ARES_SUCCESS) {
ares__buf_tag_rollback(conn->in_buf);
break;
}
/* Not enough data for a full response yet */
if (ares__buf_consume(server->tcp_parser, dns_len) != ARES_SUCCESS) {
ares__buf_tag_rollback(server->tcp_parser);
if (ares__buf_consume(conn->in_buf, dns_len) != ARES_SUCCESS) {
ares__buf_tag_rollback(conn->in_buf);
break;
}
/* Can't fail except for misuse */
data = ares__buf_tag_fetch(server->tcp_parser, &data_len);
data = ares__buf_tag_fetch(conn->in_buf, &data_len);
if (data == NULL || data_len < 2) {
ares__buf_tag_clear(server->tcp_parser);
ares__buf_tag_clear(conn->in_buf);
break;
}
@ -369,126 +492,36 @@ static void read_tcp_data(ares_channel_t *channel, ares_conn_t *conn,
data_len -= 2;
/* We finished reading this answer; process it */
status = process_answer(channel, data, data_len, conn, ARES_TRUE, now);
status = process_answer(channel, data, data_len, conn, now);
if (status != ARES_SUCCESS) {
handle_conn_error(conn, ARES_TRUE, status);
return;
}
/* Since we processed the answer, clear the tag so space can be reclaimed */
ares__buf_tag_clear(server->tcp_parser);
ares__buf_tag_clear(conn->in_buf);
}
}
static ares_socket_t *channel_socket_list(const ares_channel_t *channel,
size_t *num)
static void read_conn(ares_conn_t *conn, const ares_timeval_t *now)
{
ares__slist_node_t *snode;
ares__array_t *arr = ares__array_create(sizeof(ares_socket_t), NULL);
*num = 0;
if (arr == NULL) {
return NULL; /* LCOV_EXCL_LINE: OutOfMemory */
}
for (snode = ares__slist_node_first(channel->servers); snode != NULL;
snode = ares__slist_node_next(snode)) {
ares_server_t *server = ares__slist_node_val(snode);
ares__llist_node_t *node;
for (node = ares__llist_node_first(server->connections); node != NULL;
node = ares__llist_node_next(node)) {
const ares_conn_t *conn = ares__llist_node_val(node);
ares_socket_t *sptr;
ares_status_t status;
if (conn->fd == ARES_SOCKET_BAD) {
continue;
}
status = ares__array_insert_last((void **)&sptr, arr);
if (status != ARES_SUCCESS) {
ares__array_destroy(arr); /* LCOV_EXCL_LINE: OutOfMemory */
return NULL; /* LCOV_EXCL_LINE: OutOfMemory */
}
*sptr = conn->fd;
}
}
return ares__array_finish(arr, num);
}
/* If any UDP sockets select true for reading, process them. */
static void read_udp_packets_fd(ares_channel_t *channel, ares_conn_t *conn,
const ares_timeval_t *now)
{
ares_ssize_t read_len;
unsigned char buf[MAXENDSSZ + 1];
#ifdef HAVE_RECVFROM
ares_socklen_t fromlen;
union {
struct sockaddr sa;
struct sockaddr_in sa4;
struct sockaddr_in6 sa6;
} from;
memset(&from, 0, sizeof(from));
#endif
/* To reduce event loop overhead, read and process as many
* packets as we can. */
do {
if (conn->fd == ARES_SOCKET_BAD) {
read_len = -1;
} else {
if (conn->server->addr.family == AF_INET) {
fromlen = sizeof(from.sa4);
} else {
fromlen = sizeof(from.sa6);
}
read_len = ares__socket_recvfrom(channel, conn->fd, (void *)buf,
sizeof(buf), 0, &from.sa, &fromlen);
}
if (read_len == 0) {
/* UDP is connectionless, so result code of 0 is a 0-length UDP
* packet, and not an indication the connection is closed like on
* tcp */
continue;
} else if (read_len < 0) {
if (ares__socket_try_again(SOCKERRNO)) {
break;
}
handle_conn_error(conn, ARES_TRUE, ARES_ECONNREFUSED);
/* TODO: There might be a potential issue here where there was a read that
* read some data, then looped and read again and got a disconnect.
* Right now, that would cause a resend instead of processing the data
* we have. This is fairly unlikely to occur due to only looping if
* a full buffer of 65535 bytes was read. */
if (read_conn_packets(conn) != ARES_SUCCESS) {
return;
#ifdef HAVE_RECVFROM
} else if (!same_address(&from.sa, &conn->server->addr)) {
/* The address the response comes from does not match the address we
* sent the request to. Someone may be attempting to perform a cache
* poisoning attack. */
continue;
#endif
} else {
process_answer(channel, buf, (size_t)read_len, conn, ARES_FALSE, now);
}
/* Try to read again only if *we* set up the socket, otherwise it may be
* a blocking socket and would cause recvfrom to hang. */
} while (read_len >= 0 && channel->sock_funcs == NULL);
read_answers(conn, now);
}
static void read_packets(ares_channel_t *channel, fd_set *read_fds,
static void process_read(ares_channel_t *channel, fd_set *read_fds,
ares_socket_t read_fd, const ares_timeval_t *now)
{
size_t i;
ares_socket_t *socketlist = NULL;
size_t num_sockets = 0;
ares_conn_t *conn = NULL;
ares__llist_node_t *node = NULL;
if (!read_fds && (read_fd == ARES_SOCKET_BAD)) {
@ -503,13 +536,7 @@ static void read_packets(ares_channel_t *channel, fd_set *read_fds,
return;
}
conn = ares__llist_node_val(node);
if (conn->flags & ARES_CONN_FLAG_TCP) {
read_tcp_data(channel, conn, now);
} else {
read_udp_packets_fd(channel, conn, now);
}
read_conn(ares__llist_node_val(node), now);
return;
}
@ -537,13 +564,7 @@ static void read_packets(ares_channel_t *channel, fd_set *read_fds,
return;
}
conn = ares__llist_node_val(node);
if (conn->flags & ARES_CONN_FLAG_TCP) {
read_tcp_data(channel, conn, now);
} else {
read_udp_packets_fd(channel, conn, now);
}
read_conn(ares__llist_node_val(node), now);
}
ares_free(socketlist);
@ -607,7 +628,7 @@ done:
* the connection to be terminated after this call. */
static ares_status_t process_answer(ares_channel_t *channel,
const unsigned char *abuf, size_t alen,
ares_conn_t *conn, ares_bool_t tcp,
ares_conn_t *conn,
const ares_timeval_t *now)
{
ares_query_t *query;
@ -618,6 +639,11 @@ static ares_status_t process_answer(ares_channel_t *channel,
ares_status_t status;
ares_bool_t is_cached = ARES_FALSE;
/* UDP can have 0-byte messages, drop them to the ground */
if (alen == 0) {
return ARES_SUCCESS;
}
/* Parse the response */
status = ares_dns_parse(abuf, alen, 0, &rdnsrec);
if (status != ARES_SUCCESS) {
@ -681,7 +707,8 @@ static ares_status_t process_answer(ares_channel_t *channel,
* don't accept the packet, and switch the query to TCP if we hadn't
* done so already.
*/
if (ares_dns_record_get_flags(rdnsrec) & ARES_FLAG_TC && !tcp &&
if (ares_dns_record_get_flags(rdnsrec) & ARES_FLAG_TC &&
!(conn->flags & ARES_CONN_FLAG_TCP) &&
!(channel->flags & ARES_FLAG_IGNTC)) {
query->using_tcp = ARES_TRUE;
ares__send_query(query, now);
@ -971,9 +998,6 @@ static ares_status_t ares__conn_query_write(ares_conn_t *conn,
ares_query_t *query,
const ares_timeval_t *now)
{
unsigned char *qbuf = NULL;
size_t qbuf_len = 0;
ares_ssize_t len;
ares_server_t *server = conn->server;
ares_channel_t *channel = server->channel;
ares_status_t status;
@ -983,64 +1007,33 @@ static ares_status_t ares__conn_query_write(ares_conn_t *conn,
return status;
}
if (conn->flags & ARES_CONN_FLAG_TCP) {
size_t prior_len = ares__buf_len(server->tcp_send);
status = ares_dns_write_buf_tcp(query->query, server->tcp_send);
/* We write using the TCP format even for UDP, we just strip the length
* before putting on the wire */
status = ares_dns_write_buf_tcp(query->query, conn->out_buf);
if (status != ARES_SUCCESS) {
return status;
}
if (conn->flags & ARES_CONN_FLAG_TFO_INITIAL) {
/* When using TFO, we need to put it on the wire immediately. */
size_t data_len;
const unsigned char *data = NULL;
data = ares__buf_peek(server->tcp_send, &data_len);
len = ares__conn_write(conn, data, data_len);
if (len <= 0) {
if (ares__socket_try_again(SOCKERRNO)) {
/* This means we must not have qualified for TFO, keep the data
* buffered, wait on write signal. */
return ARES_SUCCESS;
}
/* TCP TFO might delay failure. Reflect that here */
return ARES_ECONNREFUSED;
}
/* Consume what was written */
ares__buf_consume(server->tcp_send, (size_t)len);
/* Not pending a TFO write and not connected, so we can't even try to
* write until we get a signal */
if (conn->flags & ARES_CONN_FLAG_TCP &&
!(conn->state_flags & ARES_CONN_STATE_CONNECTED) &&
!(conn->flags & ARES_CONN_FLAG_TFO_INITIAL)) {
return ARES_SUCCESS;
}
if (prior_len == 0) {
SOCK_STATE_CALLBACK(channel, conn->fd, 1, 1);
}
/* Delay actual write if possible (TCP only, and only if callback
* configured) */
if (channel->notify_pending_write_cb && !channel->notify_pending_write &&
conn->flags & ARES_CONN_FLAG_TCP) {
channel->notify_pending_write = ARES_TRUE;
channel->notify_pending_write_cb(channel->notify_pending_write_cb_data);
return ARES_SUCCESS;
}
/* UDP Here */
status = ares_dns_write(query->query, &qbuf, &qbuf_len);
if (status != ARES_SUCCESS) {
return status;
}
len = ares__conn_write(conn, qbuf, qbuf_len);
ares_free(qbuf);
if (len == -1) {
if (ares__socket_try_again(SOCKERRNO)) {
return ARES_ESERVFAIL;
}
/* UDP is connection-less, but we might receive an ICMP unreachable which
* means we can't talk to the remote host at all and that will be
* reflected here */
return ARES_ECONNREFUSED;
}
return ARES_SUCCESS;
/* Unfortunately we need to write right away and can't aggregate multiple
* queries into a single write. */
return ares__conn_flush(conn);
}
ares_status_t ares__send_query(ares_query_t *query, const ares_timeval_t *now)
@ -1150,6 +1143,7 @@ ares_status_t ares__send_query(ares_query_t *query, const ares_timeval_t *now)
query->conn = conn;
conn->total_queries++;
return ARES_SUCCESS;
}
@ -1213,36 +1207,6 @@ done:
return rv;
}
static ares_bool_t same_address(const struct sockaddr *sa,
const struct ares_addr *aa)
{
const void *addr1;
const void *addr2;
if (sa->sa_family == aa->family) {
switch (aa->family) {
case AF_INET:
addr1 = &aa->addr.addr4;
addr2 = &(CARES_INADDR_CAST(const struct sockaddr_in *, sa))->sin_addr;
if (memcmp(addr1, addr2, sizeof(aa->addr.addr4)) == 0) {
return ARES_TRUE; /* match */
}
break;
case AF_INET6:
addr1 = &aa->addr.addr6;
addr2 =
&(CARES_INADDR_CAST(const struct sockaddr_in6 *, sa))->sin6_addr;
if (memcmp(addr1, addr2, sizeof(aa->addr.addr6)) == 0) {
return ARES_TRUE; /* match */
}
break;
default:
break; /* LCOV_EXCL_LINE */
}
}
return ARES_FALSE; /* different */
}
static void ares_detach_query(ares_query_t *query)
{
/* Remove the query from all the lists in which it is linked */

134
src/lib/ares_setup.h
Unescape View File

@ -199,34 +199,11 @@
#endif
#ifdef __hpux
# if !defined(_XOPEN_SOURCE_EXTENDED) || defined(_KERNEL)
# ifdef _APP32_64BIT_OFF_T
# define OLD_APP32_64BIT_OFF_T _APP32_64BIT_OFF_T
# undef _APP32_64BIT_OFF_T
# else
# undef OLD_APP32_64BIT_OFF_T
# endif
# endif
#endif
#ifdef __hpux
# if !defined(_XOPEN_SOURCE_EXTENDED) || defined(_KERNEL)
# ifdef OLD_APP32_64BIT_OFF_T
# define _APP32_64BIT_OFF_T OLD_APP32_64BIT_OFF_T
# undef OLD_APP32_64BIT_OFF_T
# endif
# endif
#endif
/*
* Definition of timeval struct for platforms that don't have it.
*/
/* Definition of timeval struct for platforms that don't have it. */
#ifndef HAVE_STRUCT_TIMEVAL
struct timeval {
long tv_sec;
ares_int64_t tv_sec;
long tv_usec;
};
#endif
@ -257,111 +234,4 @@ struct timeval {
} while (0)
#endif
/*
* Macro SOCKERRNO / SET_SOCKERRNO() returns / sets the *socket-related* errno
* (or equivalent) on this platform to hide platform details to code using it.
*/
#ifdef USE_WINSOCK
# define SOCKERRNO ((int)WSAGetLastError())
# define SET_SOCKERRNO(x) (WSASetLastError((int)(x)))
#else
# define SOCKERRNO (errno)
# define SET_SOCKERRNO(x) (errno = (x))
#endif
/*
* Macro ERRNO / SET_ERRNO() returns / sets the NOT *socket-related* errno
* (or equivalent) on this platform to hide platform details to code using it.
*/
#if defined(WIN32) && !defined(WATT32)
# define ERRNO ((int)GetLastError())
# define SET_ERRNO(x) (SetLastError((DWORD)(x)))
#else
# define ERRNO (errno)
# define SET_ERRNO(x) (errno = (x))
#endif
/*
* Portable error number symbolic names defined to Winsock error codes.
*/
#ifdef USE_WINSOCK
# undef EBADF /* override definition in errno.h */
# define EBADF WSAEBADF
# undef EINTR /* override definition in errno.h */
# define EINTR WSAEINTR
# undef EINVAL /* override definition in errno.h */
# define EINVAL WSAEINVAL
# undef EWOULDBLOCK /* override definition in errno.h */
# define EWOULDBLOCK WSAEWOULDBLOCK
# undef EINPROGRESS /* override definition in errno.h */
# define EINPROGRESS WSAEINPROGRESS
# undef EALREADY /* override definition in errno.h */
# define EALREADY WSAEALREADY
# undef ENOTSOCK /* override definition in errno.h */
# define ENOTSOCK WSAENOTSOCK
# undef EDESTADDRREQ /* override definition in errno.h */
# define EDESTADDRREQ WSAEDESTADDRREQ
# undef EMSGSIZE /* override definition in errno.h */
# define EMSGSIZE WSAEMSGSIZE
# undef EPROTOTYPE /* override definition in errno.h */
# define EPROTOTYPE WSAEPROTOTYPE
# undef ENOPROTOOPT /* override definition in errno.h */
# define ENOPROTOOPT WSAENOPROTOOPT
# undef EPROTONOSUPPORT /* override definition in errno.h */
# define EPROTONOSUPPORT WSAEPROTONOSUPPORT
# define ESOCKTNOSUPPORT WSAESOCKTNOSUPPORT
# undef EOPNOTSUPP /* override definition in errno.h */
# define EOPNOTSUPP WSAEOPNOTSUPP
# define EPFNOSUPPORT WSAEPFNOSUPPORT
# undef EAFNOSUPPORT /* override definition in errno.h */
# define EAFNOSUPPORT WSAEAFNOSUPPORT
# undef EADDRINUSE /* override definition in errno.h */
# define EADDRINUSE WSAEADDRINUSE
# undef EADDRNOTAVAIL /* override definition in errno.h */
# define EADDRNOTAVAIL WSAEADDRNOTAVAIL
# undef ENETDOWN /* override definition in errno.h */
# define ENETDOWN WSAENETDOWN
# undef ENETUNREACH /* override definition in errno.h */
# define ENETUNREACH WSAENETUNREACH
# undef ENETRESET /* override definition in errno.h */
# define ENETRESET WSAENETRESET
# undef ECONNABORTED /* override definition in errno.h */
# define ECONNABORTED WSAECONNABORTED
# undef ECONNRESET /* override definition in errno.h */
# define ECONNRESET WSAECONNRESET
# undef ENOBUFS /* override definition in errno.h */
# define ENOBUFS WSAENOBUFS
# undef EISCONN /* override definition in errno.h */
# define EISCONN WSAEISCONN
# undef ENOTCONN /* override definition in errno.h */
# define ENOTCONN WSAENOTCONN
# define ESHUTDOWN WSAESHUTDOWN
# define ETOOMANYREFS WSAETOOMANYREFS
# undef ETIMEDOUT /* override definition in errno.h */
# define ETIMEDOUT WSAETIMEDOUT
# undef ECONNREFUSED /* override definition in errno.h */
# define ECONNREFUSED WSAECONNREFUSED
# undef ELOOP /* override definition in errno.h */
# define ELOOP WSAELOOP
# ifndef ENAMETOOLONG /* possible previous definition in errno.h */
# define ENAMETOOLONG WSAENAMETOOLONG
# endif
# define EHOSTDOWN WSAEHOSTDOWN
# undef EHOSTUNREACH /* override definition in errno.h */
# define EHOSTUNREACH WSAEHOSTUNREACH
# ifndef ENOTEMPTY /* possible previous definition in errno.h */
# define ENOTEMPTY WSAENOTEMPTY
# endif
# define EPROCLIM WSAEPROCLIM
# define EUSERS WSAEUSERS
# define EDQUOT WSAEDQUOT
# define ESTALE WSAESTALE
# define EREMOTE WSAEREMOTE
#endif
#endif /* __ARES_SETUP_H */

12
src/lib/ares_update_servers.c
Unescape View File

@ -608,18 +608,6 @@ static ares_status_t ares__server_create(ares_channel_t *channel,
server->ll_scope = sconfig->ll_scope;
}
server->tcp_parser = ares__buf_create();
if (server->tcp_parser == NULL) {
status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */
goto done; /* LCOV_EXCL_LINE: OutOfMemory */
}
server->tcp_send = ares__buf_create();
if (server->tcp_send == NULL) {
status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */
goto done; /* LCOV_EXCL_LINE: OutOfMemory */
}
server->connections = ares__llist_create(NULL);
if (server->connections == NULL) {
status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */

2
src/lib/event/ares_event.h
Unescape View File

@ -96,6 +96,8 @@ struct ares_event_thread {
/*! Reference to the ares channel, for being able to call things like
* ares_timeout() and ares_process_fd(). */
ares_channel_t *channel;
/*! Whether or not on the next loop we should process a pending write */
ares_bool_t process_pending_write;
/*! Not-yet-processed event handle updates. These will get enqueued by a
* thread other than the event thread itself. The event thread will then
* be woken then process these updates itself */

25
src/lib/event/ares_event_thread.c
Unescape View File

@ -216,6 +216,17 @@ static void ares_event_thread_sockstate_cb(void *data, ares_socket_t socket_fd,
NULL, NULL, NULL);
}
static void ares_event_thread_notifywrite_cb(void *data)
{
ares_event_thread_t *e = data;
ares__thread_mutex_lock(e->mutex);
e->process_pending_write = ARES_TRUE;
ares__thread_mutex_unlock(e->mutex);
ares_event_thread_wake(e);
}
static void ares_event_process_updates(ares_event_thread_t *e)
{
ares__llist_node_t *node;
@ -310,6 +321,7 @@ static void *ares_event_thread(void *arg)
struct timeval tv;
const struct timeval *tvout;
unsigned long timeout_ms = 0; /* 0 = unlimited */
ares_bool_t process_pending_write;
ares_event_process_updates(e);
@ -326,6 +338,15 @@ static void *ares_event_thread(void *arg)
e->ev_sys->wait(e, timeout_ms);
/* Process pending write operation */
ares__thread_mutex_lock(e->mutex);
process_pending_write = e->process_pending_write;
e->process_pending_write = ARES_FALSE;
ares__thread_mutex_unlock(e->mutex);
if (process_pending_write) {
ares_process_pending_write(e->channel);
}
/* Each iteration should do timeout processing */
if (e->isup) {
ares_process_fd(e->channel, ARES_SOCKET_BAD, ARES_SOCKET_BAD);
@ -381,6 +402,8 @@ void ares_event_thread_destroy(ares_channel_t *channel)
ares_event_thread_destroy_int(e);
channel->sock_state_cb_data = NULL;
channel->sock_state_cb = NULL;
channel->notify_pending_write_cb = NULL;
channel->notify_pending_write_cb_data = NULL;
}
static const ares_event_sys_t *ares_event_fetch_sys(ares_evsys_t evsys)
@ -485,6 +508,8 @@ ares_status_t ares_event_thread_init(ares_channel_t *channel)
channel->sock_state_cb = ares_event_thread_sockstate_cb;
channel->sock_state_cb_data = e;
channel->notify_pending_write_cb = ares_event_thread_notifywrite_cb;
channel->notify_pending_write_cb_data = e;
if (!e->ev_sys->init(e)) {
/* LCOV_EXCL_START: UntestablePath */

37
src/lib/inet_net_pton.c
Unescape View File

@ -32,6 +32,20 @@
#include "ares_ipv6.h"
#include "ares_inet_net_pton.h"
#ifdef USE_WINSOCK
# define SOCKERRNO ((int)WSAGetLastError())
# define SET_SOCKERRNO(x) (WSASetLastError((int)(x)))
# undef EMSGSIZE
# define EMSGSIZE WSAEMSGSIZE
# undef ENOENT
# define ENOENT WSA_INVALID_PARAMETER
# undef EAFNOSUPPORT
# define EAFNOSUPPORT WSAEAFNOSUPPORT
#else
# define SOCKERRNO (errno)
# define SET_SOCKERRNO(x) (errno = (x))
#endif
const struct ares_in6_addr ares_in6addr_any = { { { 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0 } } };
@ -195,11 +209,11 @@ static int ares_inet_net_pton_ipv4(const char *src, unsigned char *dst,
return bits;
enoent:
SET_ERRNO(ENOENT);
SET_SOCKERRNO(ENOENT);
return -1;
emsgsize:
SET_ERRNO(EMSGSIZE);
SET_SOCKERRNO(EMSGSIZE);
return -1;
}
@ -343,7 +357,7 @@ static int ares_inet_pton6(const char *src, unsigned char *dst)
return 1;
enoent:
SET_ERRNO(ENOENT);
SET_SOCKERRNO(ENOENT);
return -1;
}
@ -358,7 +372,7 @@ static int ares_inet_net_pton_ipv6(const char *src, unsigned char *dst,
char *sep;
if (ares_strlen(src) >= sizeof buf) {
SET_ERRNO(EMSGSIZE);
SET_SOCKERRNO(EMSGSIZE);
return -1;
}
ares_strcpy(buf, src, sizeof buf);
@ -377,14 +391,14 @@ static int ares_inet_net_pton_ipv6(const char *src, unsigned char *dst,
bits = 128;
} else {
if (!getbits(sep, &bits)) {
SET_ERRNO(ENOENT);
SET_SOCKERRNO(ENOENT);
return -1;
}
}
bytes = (bits + 7) / 8;
if (bytes > size) {
SET_ERRNO(EMSGSIZE);
SET_SOCKERRNO(EMSGSIZE);
return -1;
}
memcpy(dst, &in6, bytes);
@ -401,13 +415,9 @@ static int ares_inet_net_pton_ipv6(const char *src, unsigned char *dst,
* number of bits, either imputed classfully or specified with /CIDR,
* or -1 if some failure occurred (check errno). ENOENT means it was
* not a valid network specification.
* note:
* On Windows we store the error in the thread errno, not
* in the winsock error code. This is to avoid losing the
* actual last winsock error. So use macro ERRNO to fetch the
* errno this function sets when returning (-1), not SOCKERRNO.
* author:
* Paul Vixie (ISC), June 1996
*
*/
int ares_inet_net_pton(int af, const char *src, void *dst, size_t size)
{
@ -417,7 +427,6 @@ int ares_inet_net_pton(int af, const char *src, void *dst, size_t size)
case AF_INET6:
return ares_inet_net_pton_ipv6(src, dst, size);
default:
SET_ERRNO(EAFNOSUPPORT);
return -1;
}
}
@ -432,11 +441,11 @@ int ares_inet_pton(int af, const char *src, void *dst)
} else if (af == AF_INET6) {
size = sizeof(struct ares_in6_addr);
} else {
SET_ERRNO(EAFNOSUPPORT);
SET_SOCKERRNO(EAFNOSUPPORT);
return -1;
}
result = ares_inet_net_pton(af, src, dst, size);
if (result == -1 && ERRNO == ENOENT) {
if (result == -1 && SOCKERRNO == ENOENT) {
return 0;
}
return (result > -1) ? 1 : -1;

29
src/lib/inet_ntop.c
Unescape View File

@ -29,6 +29,22 @@
#include "ares_nameser.h"
#include "ares_ipv6.h"
#ifdef USE_WINSOCK
# define SOCKERRNO ((int)WSAGetLastError())
# define SET_SOCKERRNO(x) (WSASetLastError((int)(x)))
# undef EMSGSIZE
# define EMSGSIZE WSAEMSGSIZE
# undef ENOENT
# define ENOENT WSA_INVALID_PARAMETER
# undef EAFNOSUPPORT
# define EAFNOSUPPORT WSAEAFNOSUPPORT
# undef ENOSPC
# define ENOSPC WSA_INVALID_PARAMETER
#else
# define SOCKERRNO (errno)
# define SET_SOCKERRNO(x) (errno = (x))
#endif
/*
* WARNING: Don't even consider trying to compile this on a system where
* sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
@ -42,11 +58,6 @@ static const char *inet_ntop6(const unsigned char *src, char *dst, size_t size);
* convert a network format address to presentation format.
* return:
* pointer to presentation format address (`dst'), or NULL (see errno).
* note:
* On Windows we store the error in the thread errno, not
* in the winsock error code. This is to avoid losing the
* actual last winsock error. So use macro ERRNO to fetch the
* errno this function sets when returning NULL, not SOCKERRNO.
* author:
* Paul Vixie, 1996.
*/
@ -61,7 +72,7 @@ const char *ares_inet_ntop(int af, const void *src, char *dst,
default:
break;
}
SET_ERRNO(EAFNOSUPPORT);
SET_SOCKERRNO(EAFNOSUPPORT);
return NULL;
}
@ -82,13 +93,13 @@ static const char *inet_ntop4(const unsigned char *src, char *dst, size_t size)
char tmp[sizeof("255.255.255.255")];
if (size < sizeof(tmp)) {
SET_ERRNO(ENOSPC);
SET_SOCKERRNO(ENOSPC);
return NULL;
}
if ((size_t)snprintf(tmp, sizeof(tmp), fmt, src[0], src[1], src[2], src[3]) >=
size) {
SET_ERRNO(ENOSPC);
SET_SOCKERRNO(ENOSPC);
return NULL;
}
ares_strcpy(dst, tmp, size);
@ -200,7 +211,7 @@ static const char *inet_ntop6(const unsigned char *src, char *dst, size_t size)
* Check for overflow, copy, and we're done.
*/
if ((size_t)(tp - tmp) > size) {
SET_ERRNO(ENOSPC);
SET_SOCKERRNO(ENOSPC);
return NULL;
}
ares_strcpy(dst, tmp, size);

5
src/lib/legacy/ares_fds.c
Unescape View File

@ -68,8 +68,9 @@ int ares_fds(const ares_channel_t *channel, fd_set *read_fds, fd_set *write_fds)
nfds = conn->fd + 1;
}
/* TCP only wait on write if we have buffered data */
if (conn->flags & ARES_CONN_FLAG_TCP && ares__buf_len(server->tcp_send)) {
/* TCP only wait on write if we have the flag set */
if (conn->flags & ARES_CONN_FLAG_TCP &&
conn->state_flags & ARES_CONN_STATE_WRITE) {
FD_SET(conn->fd, write_fds);
}
}

3
src/lib/legacy/ares_getsock.c
Unescape View File

@ -71,7 +71,8 @@ int ares_getsock(const ares_channel_t *channel, ares_socket_t *socks,
bitmap |= ARES_GETSOCK_READABLE(setbits, sockindex);
}
if (conn->flags & ARES_CONN_FLAG_TCP && ares__buf_len(server->tcp_send)) {
if (conn->flags & ARES_CONN_FLAG_TCP &&
conn->state_flags & ARES_CONN_STATE_WRITE) {
/* then the tcp socket is also writable! */
bitmap |= ARES_GETSOCK_WRITABLE(setbits, sockindex);
}

2
src/lib/str/ares__buf.c
Unescape View File

@ -1234,7 +1234,7 @@ ares_status_t ares__buf_load_file(const char *filename, ares__buf_t *buf)
fp = fopen(filename, "rb");
if (fp == NULL) {
int error = ERRNO;
int error = errno;
switch (error) {
case ENOENT:
case ESRCH:

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