Dominick Meglio
20 years ago
parent
a6f7820033
commit
aba0b775ea
10 changed files with 1034 additions and 434 deletions
@ -0,0 +1,145 @@ |
|||||||
|
.\" $Id$ |
||||||
|
.\" |
||||||
|
.\" Copyright 2005 by Dominick Meglio. |
||||||
|
.\" |
||||||
|
.\" Permission to use, copy, modify, and distribute this |
||||||
|
.\" software and its documentation for any purpose and without |
||||||
|
.\" fee is hereby granted, provided that the above copyright |
||||||
|
.\" notice appear in all copies and that both that copyright |
||||||
|
.\" notice and this permission notice appear in supporting |
||||||
|
.\" documentation, and that the name of M.I.T. not be used in |
||||||
|
.\" advertising or publicity pertaining to distribution of the |
||||||
|
.\" software without specific, written prior permission. |
||||||
|
.\" M.I.T. makes no representations about the suitability of |
||||||
|
.\" this software for any purpose. It is provided "as is" |
||||||
|
.\" without express or implied warranty. |
||||||
|
.\" |
||||||
|
.TH ARES_GETNAMEINFO 3 "16 May 2005" |
||||||
|
.SH NAME |
||||||
|
ares_getnameinfo \- Address-to-nodename translation in protocol-independent manner |
||||||
|
.SH SYNOPSIS |
||||||
|
.nf |
||||||
|
.B #include <ares.h> |
||||||
|
.PP |
||||||
|
.B typedef void (*ares_nameinfo_callback)(void *\fIarg\fP, int \fIstatus\fP, |
||||||
|
.B char *\fInode\fP, char *\fIservice\fP) |
||||||
|
.PP |
||||||
|
.B void ares_getnameinfo(ares_channel \fIchannel\fP, const struct sockaddr *\fIsa\fP, |
||||||
|
.B socklen_t \fIsalen\fP, int \fIflags\fP, ares_nameinfo_callback \fIcallback\fP, |
||||||
|
.B void *\fIarg\fP) |
||||||
|
.fi |
||||||
|
.SH DESCRIPTION |
||||||
|
The |
||||||
|
.B ares_getnameinfo |
||||||
|
function is defined for protocol-independent address translation. The function |
||||||
|
is a combination of \fIares_gethostbyaddr(3)\fP and \fIgetservbyport(3)\fP. The function will |
||||||
|
translate the address either by executing a host query on the name service channel |
||||||
|
identified by |
||||||
|
.IR channel |
||||||
|
or it will attempt to resolve it locally if possible. |
||||||
|
The parameters |
||||||
|
.I sa |
||||||
|
and |
||||||
|
.I len |
||||||
|
give the address as a sockaddr structure, and |
||||||
|
.I flags |
||||||
|
gives the options that the function will use. Valid flags are listed below: |
||||||
|
.TP 19 |
||||||
|
.B ARES_NI_NOFQDN |
||||||
|
Only the nodename portion of the FQDN is returned for local hosts. |
||||||
|
.TP 19 |
||||||
|
.B ARES_NI_NUMERICHOST |
||||||
|
The numeric form of the hostname is returned rather than the name. |
||||||
|
.TP 19 |
||||||
|
.B ARES_NI_NAMEREQD |
||||||
|
An error is returned if the hostname cannot be found in the DNS. |
||||||
|
.TP 19 |
||||||
|
.B ARES_NI_NUMERICSERV |
||||||
|
The numeric form of the service is returned rather than the name. |
||||||
|
.TP 19 |
||||||
|
.B ARES_NI_TCP |
||||||
|
The service name is to be looked up for the TCP protocol. |
||||||
|
.TP 19 |
||||||
|
.B ARES_NI_UDP |
||||||
|
The service name is to be looked up for the UDP protocol. |
||||||
|
.TP 19 |
||||||
|
.B ARES_NI_SCTP |
||||||
|
The service name is to be looked up for the SCTP protocol. |
||||||
|
.TP 19 |
||||||
|
.B ARES_NI_DCCP |
||||||
|
The service name is to be looked up for the DCCP protocol. |
||||||
|
.TP 19 |
||||||
|
.B ARES_NI_NUMERICSCOPE |
||||||
|
The numeric form of the scope ID is returned rather than the name. |
||||||
|
.TP 19 |
||||||
|
.B ARES_NI_LOOKUPHOST |
||||||
|
A hostname lookup is being requested. |
||||||
|
.TP 19 |
||||||
|
.B ARES_NI_LOOKUPSERVICE |
||||||
|
A service name lookup is being requested. |
||||||
|
.PP |
||||||
|
When the query |
||||||
|
is complete or has |
||||||
|
failed, the ares library will invoke \fIcallback\fP. Completion or failure of |
||||||
|
the query may happen immediately, or may happen during a later call to |
||||||
|
\fIares_process(3)\fP, \fIares_destroy(3)\fP or \fIares_cancel(3)\fP. |
||||||
|
.PP |
||||||
|
The callback argument |
||||||
|
.I arg |
||||||
|
is copied from the |
||||||
|
.B ares_getnameinfo |
||||||
|
argument |
||||||
|
.IR arg . |
||||||
|
The callback argument |
||||||
|
.I status |
||||||
|
indicates whether the query succeeded and, if not, how it failed. It |
||||||
|
may have any of the following values: |
||||||
|
.TP 19 |
||||||
|
.B ARES_SUCCESS |
||||||
|
The host lookup completed successfully. |
||||||
|
.TP 19 |
||||||
|
.B ARES_ENOTIMP |
||||||
|
The ares library does not know how to look up addresses of type |
||||||
|
.IR family . |
||||||
|
.TP 19 |
||||||
|
.B ARES_ENOTFOUND |
||||||
|
The address |
||||||
|
.I addr |
||||||
|
was not found. |
||||||
|
.TP 19 |
||||||
|
.B ARES_ENOMEM |
||||||
|
Memory was exhausted. |
||||||
|
.TP 19 |
||||||
|
.B ARES_EDESTRUCTION |
||||||
|
The name service channel |
||||||
|
.I channel |
||||||
|
is being destroyed; the query will not be completed. |
||||||
|
.TP 19 |
||||||
|
.B ARES_EBADFLAGS |
||||||
|
The |
||||||
|
.I flags |
||||||
|
parameter contains an illegal value. |
||||||
|
.PP |
||||||
|
On successful completion of the query, the callback argument |
||||||
|
.I node |
||||||
|
contains a string representing the hostname (assuming |
||||||
|
.B ARES_NI_LOOKUPHOST |
||||||
|
was specified). Additionally, |
||||||
|
.I service |
||||||
|
contains a string representing the service name (assuming |
||||||
|
.B ARES_NI_LOOKUPSERVICE |
||||||
|
was specified). |
||||||
|
If the query did not complete successfully, or one of the values |
||||||
|
was not requested, |
||||||
|
.I node |
||||||
|
or |
||||||
|
.I service |
||||||
|
will be |
||||||
|
.BR NULL . |
||||||
|
.SH SEE ALSO |
||||||
|
.BR ares_process (3), |
||||||
|
.BR ares_getaddrinfo (3) |
||||||
|
.SH AUTHOR |
||||||
|
Dominick Meglio |
||||||
|
.br |
||||||
|
Copyright 2005 by Dominick Meglio. |
||||||
@ -0,0 +1,322 @@ |
|||||||
|
/* Copyright 2005 by Dominick Meglio
|
||||||
|
* |
||||||
|
* Permission to use, copy, modify, and distribute this |
||||||
|
* software and its documentation for any purpose and without |
||||||
|
* fee is hereby granted, provided that the above copyright |
||||||
|
* notice appear in all copies and that both that copyright |
||||||
|
* notice and this permission notice appear in supporting |
||||||
|
* documentation, and that the name of M.I.T. not be used in |
||||||
|
* advertising or publicity pertaining to distribution of the |
||||||
|
* software without specific, written prior permission. |
||||||
|
* M.I.T. makes no representations about the suitability of |
||||||
|
* this software for any purpose. It is provided "as is" |
||||||
|
* without express or implied warranty. |
||||||
|
*/ |
||||||
|
#include "setup.h" |
||||||
|
#include <sys/types.h> |
||||||
|
|
||||||
|
#if defined(WIN32) && !defined(WATT32) |
||||||
|
#include "nameser.h" |
||||||
|
#else |
||||||
|
#include <sys/socket.h> |
||||||
|
#include <netinet/in.h> |
||||||
|
#include <netdb.h> |
||||||
|
#include <arpa/nameser.h> |
||||||
|
#ifdef HAVE_ARPA_NAMESER_COMPAT_H |
||||||
|
#include <arpa/nameser_compat.h> |
||||||
|
#endif |
||||||
|
#endif |
||||||
|
|
||||||
|
#ifdef HAVE_NET_IF_H |
||||||
|
#include <net/if.h> |
||||||
|
#endif |
||||||
|
|
||||||
|
#include <stdio.h> |
||||||
|
#include <stdlib.h> |
||||||
|
#include <string.h> |
||||||
|
|
||||||
|
#include "ares.h" |
||||||
|
#include "ares_private.h" |
||||||
|
#include "ares_ipv6.h" |
||||||
|
#include "inet_ntop.h" |
||||||
|
|
||||||
|
#ifdef WATT32 |
||||||
|
#undef WIN32 |
||||||
|
#endif |
||||||
|
|
||||||
|
struct nameinfo_query { |
||||||
|
ares_nameinfo_callback callback; |
||||||
|
void *arg; |
||||||
|
union { |
||||||
|
struct sockaddr_in addr4; |
||||||
|
struct sockaddr_in6 addr6; |
||||||
|
} addr; |
||||||
|
int family; |
||||||
|
int flags; |
||||||
|
}; |
||||||
|
|
||||||
|
#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID |
||||||
|
#define IPBUFSIZ 40+IF_NAMESIZE |
||||||
|
#else |
||||||
|
#define IPBUFSIZ 40 |
||||||
|
#endif |
||||||
|
|
||||||
|
static void nameinfo_callback(void *arg, int status, struct hostent *host); |
||||||
|
static char *lookup_service(unsigned short port, int flags, char *buf); |
||||||
|
static char *append_scopeid(struct sockaddr_in6 *addr6, unsigned int scopeid, char *buf); |
||||||
|
static char *ares_striendstr(const char *s1, const char *s2); |
||||||
|
|
||||||
|
void ares_getnameinfo(ares_channel channel, const struct sockaddr *sa, socklen_t salen, |
||||||
|
int flags, ares_nameinfo_callback callback, void *arg) |
||||||
|
{ |
||||||
|
struct sockaddr_in *addr; |
||||||
|
struct sockaddr_in6 *addr6; |
||||||
|
struct nameinfo_query *niquery; |
||||||
|
|
||||||
|
/* Verify the buffer size */ |
||||||
|
if (salen == sizeof(struct sockaddr_in)) |
||||||
|
addr = (struct sockaddr_in *)sa; |
||||||
|
else if (salen == sizeof(struct sockaddr_in6)) |
||||||
|
addr6 = (struct sockaddr_in6 *)sa; |
||||||
|
else |
||||||
|
{ |
||||||
|
callback(arg, ARES_ENOTIMP, NULL, NULL); |
||||||
|
return; |
||||||
|
} |
||||||
|
|
||||||
|
/* If neither, assume they want a host */ |
||||||
|
if (!(flags & ARES_NI_LOOKUPSERVICE) && !(flags & ARES_NI_LOOKUPHOST)) |
||||||
|
flags |= ARES_NI_LOOKUPHOST; |
||||||
|
|
||||||
|
/* All they want is a service, no need for DNS */ |
||||||
|
if ((flags & ARES_NI_LOOKUPSERVICE) && !(flags & ARES_NI_LOOKUPHOST)) |
||||||
|
{ |
||||||
|
char buf[33], *service; |
||||||
|
unsigned int port = 0; |
||||||
|
|
||||||
|
if (salen == sizeof(struct sockaddr_in)) |
||||||
|
port = addr->sin_port; |
||||||
|
else |
||||||
|
port = addr6->sin6_port; |
||||||
|
service = lookup_service(port, flags, buf); |
||||||
|
callback(arg, ARES_SUCCESS, NULL, service); |
||||||
|
return; |
||||||
|
} |
||||||
|
|
||||||
|
/* They want a host lookup */ |
||||||
|
if ((flags & ARES_NI_LOOKUPHOST)) |
||||||
|
{ |
||||||
|
/* A numeric host can be handled without DNS */ |
||||||
|
if ((flags & ARES_NI_NUMERICHOST)) |
||||||
|
{ |
||||||
|
unsigned int port = 0; |
||||||
|
char ipbuf[IPBUFSIZ]; |
||||||
|
char srvbuf[32]; |
||||||
|
char *service = NULL; |
||||||
|
ipbuf[0] = 0; |
||||||
|
|
||||||
|
/* Specifying not to lookup a host, but then saying a host
|
||||||
|
* is required has to be illegal. |
||||||
|
*/ |
||||||
|
if (flags & ARES_NI_NAMEREQD) |
||||||
|
{ |
||||||
|
callback(arg, ARES_EBADFLAGS, NULL, NULL); |
||||||
|
return; |
||||||
|
} |
||||||
|
if (salen == sizeof(struct sockaddr_in6)) |
||||||
|
{ |
||||||
|
ares_inet_ntop(AF_INET6, &addr6->sin6_addr, ipbuf, IPBUFSIZ); |
||||||
|
port = addr6->sin6_port; |
||||||
|
/* If the system supports scope IDs, use it */ |
||||||
|
#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID |
||||||
|
append_scopeid(addr6, flags, ipbuf); |
||||||
|
#endif |
||||||
|
} |
||||||
|
else |
||||||
|
{ |
||||||
|
ares_inet_ntop(AF_INET, &addr->sin_addr, ipbuf, IPBUFSIZ); |
||||||
|
port = addr->sin_port; |
||||||
|
} |
||||||
|
/* They also want a service */ |
||||||
|
if (flags & ARES_NI_LOOKUPSERVICE) |
||||||
|
service = lookup_service(port, flags, srvbuf); |
||||||
|
callback(arg, ARES_SUCCESS, ipbuf, service); |
||||||
|
return; |
||||||
|
} |
||||||
|
/* This is where a DNS lookup becomes necessary */ |
||||||
|
else |
||||||
|
{ |
||||||
|
niquery = malloc(sizeof(struct nameinfo_query)); |
||||||
|
if (!niquery) |
||||||
|
{ |
||||||
|
callback(arg, ARES_ENOMEM, NULL, NULL); |
||||||
|
return; |
||||||
|
} |
||||||
|
niquery->callback = callback; |
||||||
|
niquery->arg = arg; |
||||||
|
niquery->flags = flags; |
||||||
|
if (sa->sa_family == AF_INET)
|
||||||
|
{ |
||||||
|
niquery->family = AF_INET; |
||||||
|
memcpy(&niquery->addr.addr4, addr, sizeof(addr)); |
||||||
|
ares_gethostbyaddr(channel, &addr->sin_addr, sizeof(struct in_addr), AF_INET,
|
||||||
|
nameinfo_callback, niquery); |
||||||
|
} |
||||||
|
else |
||||||
|
{ |
||||||
|
niquery->family = AF_INET6; |
||||||
|
memcpy(&niquery->addr.addr6, addr6, sizeof(addr6)); |
||||||
|
ares_gethostbyaddr(channel, &addr6->sin6_addr, sizeof(struct in6_addr), AF_INET6,
|
||||||
|
nameinfo_callback, niquery); |
||||||
|
} |
||||||
|
} |
||||||
|
} |
||||||
|
} |
||||||
|
|
||||||
|
static void nameinfo_callback(void *arg, int status, struct hostent *host) |
||||||
|
{ |
||||||
|
struct nameinfo_query *niquery = (struct nameinfo_query *) arg; |
||||||
|
char srvbuf[33]; |
||||||
|
char *service = NULL; |
||||||
|
|
||||||
|
|
||||||
|
if (status == ARES_SUCCESS) |
||||||
|
{ |
||||||
|
/* They want a service too */ |
||||||
|
if (niquery->flags & ARES_NI_LOOKUPSERVICE) |
||||||
|
{ |
||||||
|
if (niquery->family == AF_INET) |
||||||
|
service = lookup_service(niquery->addr.addr4.sin_port, niquery->flags, srvbuf); |
||||||
|
else |
||||||
|
service = lookup_service(niquery->addr.addr6.sin6_port, niquery->flags, srvbuf); |
||||||
|
} |
||||||
|
/* NOFQDN means we have to strip off the domain name portion.
|
||||||
|
We do this by determining our own domain name, then searching the string |
||||||
|
for this domain name and removing it. |
||||||
|
*/ |
||||||
|
if (niquery->flags & ARES_NI_NOFQDN) |
||||||
|
{ |
||||||
|
char buf[255]; |
||||||
|
char *domain; |
||||||
|
gethostname(buf, 255); |
||||||
|
if ((domain = strchr(buf, '.'))) |
||||||
|
{ |
||||||
|
char *end = ares_striendstr(host->h_name, domain); |
||||||
|
if (end) |
||||||
|
*end = 0; |
||||||
|
}
|
||||||
|
} |
||||||
|
callback(niquery->arg, ARES_SUCCESS, host->h_name, service); |
||||||
|
return; |
||||||
|
} |
||||||
|
/* We couldn't find the host, but it's OK, we can use the IP */ |
||||||
|
else if (status == ARES_ENOTFOUND && !(niquery->flags & ARES_NI_NAMEREQD)) |
||||||
|
{ |
||||||
|
char ipbuf[IPBUFSIZ]; |
||||||
|
if (niquery->family == AF_INET) |
||||||
|
ares_inet_ntop(AF_INET, &niquery->addr.addr4.sin_addr, ipbuf, IPBUFSIZ); |
||||||
|
else |
||||||
|
{ |
||||||
|
ares_inet_ntop(AF_INET6, &niquery->addr.addr6.sin6_addr, ipbuf, IPBUFSIZ); |
||||||
|
#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID |
||||||
|
append_scopeid(&niquery->addr.addr6, niquery->flags, ipbuf); |
||||||
|
#endif |
||||||
|
} |
||||||
|
/* They want a service too */ |
||||||
|
if (niquery->flags & ARES_NI_LOOKUPSERVICE) |
||||||
|
{ |
||||||
|
if (niquery->family == AF_INET) |
||||||
|
service = lookup_service(niquery->addr.addr4.sin_port, niquery->flags, srvbuf); |
||||||
|
else |
||||||
|
service = lookup_service(niquery->addr.addr6.sin6_port, niquery->flags, srvbuf); |
||||||
|
} |
||||||
|
callback(niquery->arg, ARES_SUCCESS, ipbuf, service); |
||||||
|
return; |
||||||
|
} |
||||||
|
callback(niquery->arg, status, NULL, NULL); |
||||||
|
free(niquery); |
||||||
|
} |
||||||
|
|
||||||
|
static char *lookup_service(unsigned short port, int flags, char *buf) |
||||||
|
{ |
||||||
|
if (port) |
||||||
|
{ |
||||||
|
/* Just return the port as a string */ |
||||||
|
if (flags & ARES_NI_NUMERICSERV) |
||||||
|
sprintf(buf, "%u", ntohs(port)); |
||||||
|
else |
||||||
|
{ |
||||||
|
struct servent *se; |
||||||
|
char *proto; |
||||||
|
|
||||||
|
if (flags & ARES_NI_UDP) |
||||||
|
proto = "udp"; |
||||||
|
else if (flags & ARES_NI_SCTP) |
||||||
|
proto = "sctp"; |
||||||
|
else if (flags & ARES_NI_DCCP) |
||||||
|
proto = "dccp"; |
||||||
|
else |
||||||
|
proto = "tcp"; |
||||||
|
se = getservbyport(port, proto); |
||||||
|
if (se && se->s_name) |
||||||
|
strcpy(buf, se->s_name); |
||||||
|
else |
||||||
|
sprintf(buf, "%u", ntohs(port)); |
||||||
|
} |
||||||
|
return buf; |
||||||
|
} |
||||||
|
return NULL; |
||||||
|
} |
||||||
|
|
||||||
|
#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID |
||||||
|
static char *append_scopeid(struct sockaddr_in6 *addr6, unsigned int flags, char *buf) |
||||||
|
{ |
||||||
|
char tmpbuf[IF_NAMESIZE + 1]; |
||||||
|
|
||||||
|
tmpbuf[0] = '%'; |
||||||
|
#ifdef HAVE_IF_INDEXTONAME |
||||||
|
if ((flags & ARES_NI_NUMERICSCOPE) || (!IN6_IS_ADDR_LINKLOCAL(&addr6->sin6_addr) |
||||||
|
&& !IN6_IS_ADDR_MC_LINKLOCAL(&addr6->sin6_addr))) |
||||||
|
{ |
||||||
|
sprintf(&tmpbuf[1], "%u", addr6->sin6_scope_id); |
||||||
|
} |
||||||
|
else |
||||||
|
{ |
||||||
|
if (if_indextoname(addr6->sin6_scope_id, &tmpbuf[1]) == NULL) |
||||||
|
sprintf(&tmpbuf[1], "%u", addr6->sin6_scope_id); |
||||||
|
} |
||||||
|
#else |
||||||
|
sprintf(&tmpbuf[1], "%u", addr6->sin6_scope_id); |
||||||
|
#endif |
||||||
|
strcat(buf, tmpbuf); |
||||||
|
return buf; |
||||||
|
} |
||||||
|
#endif |
||||||
|
|
||||||
|
/* Determines if s1 ends with the string in s2 (case-insensitive) */ |
||||||
|
static char *ares_striendstr(const char *s1, const char *s2) |
||||||
|
{ |
||||||
|
const char *c1, *c2, *c1_begin; |
||||||
|
size_t s1_len = strlen(s1), s2_len = strlen(s2); |
||||||
|
|
||||||
|
/* If the substr is longer than the full str, it can't match */ |
||||||
|
if (s2_len > s1_len) |
||||||
|
return NULL; |
||||||
|
|
||||||
|
/* Jump to the end of s1 minus the length of s2 */ |
||||||
|
c1 = (const char *)c1_begin = s1+s1_len-s2_len; |
||||||
|
c2 = s2; |
||||||
|
while (c2 < s2+s2_len) |
||||||
|
{ |
||||||
|
if (tolower(*c1) != tolower(*c2)) |
||||||
|
return NULL; |
||||||
|
else |
||||||
|
{ |
||||||
|
c1++; |
||||||
|
c2++; |
||||||
|
} |
||||||
|
} |
||||||
|
if (c2 == c1 == NULL) |
||||||
|
return c1_begin; |
||||||
|
return NULL; |
||||||
|
} |
||||||
Loading…
Reference in new issue