Chiebot-Mirror
/
c-ares
mirror of https://github.com/c-ares/c-ares.git
8
0
Fork 0
Code Issues Projects Releases Wiki Activity

thread deadlock: make sure channel lock isn't used recursively

Browse Source
v1.26
Brad House 5 months ago
parent 5b1aacd8bd
commit fc57af0174
8 changed files with 36 additions and 44 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Unified View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 3
      docs/ares_init_options.3
  2. 14
      src/lib/ares__threads.c
  3. 6
      src/lib/ares_gethostbyaddr.c
  4. 7
      src/lib/ares_getnameinfo.c
  5. 5
      src/lib/ares_init.c
  6. 7
      src/lib/ares_private.h
  7. 14
      src/lib/ares_search.c
  8. 16
      src/lib/ares_update_servers.c

3
docs/ares_init_options.3
Unescape View File

@ -217,7 +217,8 @@ The value of
.I sock_state_cb_data .I sock_state_cb_data
will be passed as the will be passed as the
.I data .I data
argument. argument. Since this may be called cross-thread, a channel lock is NOT held
when this callback is called.
Cannot be used with \fBARES_OPT_EVENT_THREAD\fP. Cannot be used with \fBARES_OPT_EVENT_THREAD\fP.
.TP 18 .TP 18

14
src/lib/ares__threads.c
Unescape View File

@ -145,30 +145,18 @@ struct ares__thread_mutex {
ares__thread_mutex_t *ares__thread_mutex_create(void) ares__thread_mutex_t *ares__thread_mutex_create(void)
{ {
pthread_mutexattr_t attr;
ares__thread_mutex_t *mut = ares_malloc_zero(sizeof(*mut)); ares__thread_mutex_t *mut = ares_malloc_zero(sizeof(*mut));
if (mut == NULL) { if (mut == NULL) {
return NULL; return NULL;
} }
if (pthread_mutexattr_init(&attr) != 0) { if (pthread_mutex_init(&mut->mutex, NULL) != 0) {
ares_free(mut);
return NULL;
}
if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) != 0) {
goto fail;
}
if (pthread_mutex_init(&mut->mutex, &attr) != 0) {
goto fail; goto fail;
} }
pthread_mutexattr_destroy(&attr);
return mut; return mut;
fail: fail:
pthread_mutexattr_destroy(&attr);
ares_free(mut); ares_free(mut);
return NULL; return NULL;
} }

6
src/lib/ares_gethostbyaddr.c
Unescape View File

@ -68,7 +68,7 @@ static ares_status_t file_lookup(ares_channel_t *channel,
const struct ares_addr *addr, const struct ares_addr *addr,
struct hostent **host); struct hostent **host);
static void ares_gethostbyaddr_int(ares_channel_t *channel, const void *addr, void ares_gethostbyaddr_nolock(ares_channel_t *channel, const void *addr,
int addrlen, int family, int addrlen, int family,
ares_host_callback callback, void *arg) ares_host_callback callback, void *arg)
{ {
@ -118,7 +118,7 @@ void ares_gethostbyaddr(ares_channel_t *channel, const void *addr, int addrlen,
return; return;
} }
ares__channel_lock(channel); ares__channel_lock(channel);
ares_gethostbyaddr_int(channel, addr, addrlen, family, callback, arg); ares_gethostbyaddr_nolock(channel, addr, addrlen, family, callback, arg);
ares__channel_unlock(channel); ares__channel_unlock(channel);
} }
@ -138,7 +138,7 @@ static void next_lookup(struct addr_query *aquery)
return; return;
} }
aquery->remaining_lookups = p + 1; aquery->remaining_lookups = p + 1;
ares_query(aquery->channel, name, C_IN, T_PTR, addr_callback, aquery); ares_query_qid(aquery->channel, name, C_IN, T_PTR, addr_callback, aquery, NULL);
ares_free(name); ares_free(name);
return; return;
case 'f': case 'f':

7
src/lib/ares_getnameinfo.c
Unescape View File

@ -173,12 +173,13 @@ static void ares_getnameinfo_int(ares_channel_t *channel,
if (sa->sa_family == AF_INET) { if (sa->sa_family == AF_INET) {
niquery->family = AF_INET; niquery->family = AF_INET;
memcpy(&niquery->addr.addr4, addr, sizeof(niquery->addr.addr4)); memcpy(&niquery->addr.addr4, addr, sizeof(niquery->addr.addr4));
ares_gethostbyaddr(channel, &addr->sin_addr, sizeof(struct in_addr), ares_gethostbyaddr_nolock(channel, &addr->sin_addr,
AF_INET, nameinfo_callback, niquery); sizeof(struct in_addr), AF_INET,
nameinfo_callback, niquery);
} else { } else {
niquery->family = AF_INET6; niquery->family = AF_INET6;
memcpy(&niquery->addr.addr6, addr6, sizeof(niquery->addr.addr6)); memcpy(&niquery->addr.addr6, addr6, sizeof(niquery->addr.addr6));
ares_gethostbyaddr(channel, &addr6->sin6_addr, ares_gethostbyaddr_nolock(channel, &addr6->sin6_addr,
sizeof(struct ares_in6_addr), AF_INET6, sizeof(struct ares_in6_addr), AF_INET6,
nameinfo_callback, niquery); nameinfo_callback, niquery);
} }

5
src/lib/ares_init.c
Unescape View File

@ -422,7 +422,6 @@ int ares_dup(ares_channel_t **dest, ares_channel_t *src)
*dest = NULL; /* in case of failure return NULL explicitly */ *dest = NULL; /* in case of failure return NULL explicitly */
ares__channel_lock(src);
/* First get the options supported by the old ares_save_options() function, /* First get the options supported by the old ares_save_options() function,
which is most of them */ which is most of them */
rc = (ares_status_t)ares_save_options(src, &opts, &optmask); rc = (ares_status_t)ares_save_options(src, &opts, &optmask);
@ -441,6 +440,7 @@ int ares_dup(ares_channel_t **dest, ares_channel_t *src)
goto done; goto done;
} }
ares__channel_lock(src);
/* Now clone the options that ares_save_options() doesn't support, but are /* Now clone the options that ares_save_options() doesn't support, but are
* user-provided */ * user-provided */
(*dest)->sock_create_cb = src->sock_create_cb; (*dest)->sock_create_cb = src->sock_create_cb;
@ -454,7 +454,7 @@ int ares_dup(ares_channel_t **dest, ares_channel_t *src)
sizeof((*dest)->local_dev_name)); sizeof((*dest)->local_dev_name));
(*dest)->local_ip4 = src->local_ip4; (*dest)->local_ip4 = src->local_ip4;
memcpy((*dest)->local_ip6, src->local_ip6, sizeof(src->local_ip6)); memcpy((*dest)->local_ip6, src->local_ip6, sizeof(src->local_ip6));
ares__channel_unlock(src);
/* Servers are a bit unique as ares_init_options() only allows ipv4 servers /* Servers are a bit unique as ares_init_options() only allows ipv4 servers
* and not a port per server, but there are other user specified ways, that * and not a port per server, but there are other user specified ways, that
@ -486,7 +486,6 @@ int ares_dup(ares_channel_t **dest, ares_channel_t *src)
rc = ARES_SUCCESS; rc = ARES_SUCCESS;
done: done:
ares__channel_unlock(src);
return (int)rc; /* everything went fine */ return (int)rc; /* everything went fine */
} }

7
src/lib/ares_private.h
Unescape View File

@ -490,6 +490,11 @@ ares_status_t ares__hosts_entry_to_addrinfo(const ares_hosts_entry_t *entry,
ares_bool_t want_cnames, ares_bool_t want_cnames,
struct ares_addrinfo *ai); struct ares_addrinfo *ai);
/* Same as ares_gethostbyaddr() except does not take a channel lock. Use this
* if a channel lock is already held */
void ares_gethostbyaddr_nolock(ares_channel_t *channel, const void *addr,
int addrlen, int family,
ares_host_callback callback, void *arg);
/*! Parse a compressed DNS name as defined in RFC1035 starting at the current /*! Parse a compressed DNS name as defined in RFC1035 starting at the current
* offset within the buffer. * offset within the buffer.
@ -539,7 +544,9 @@ ares_status_t ares__dns_name_write(ares__buf_t *buf, ares__llist_t **list,
#define SOCK_STATE_CALLBACK(c, s, r, w) \ #define SOCK_STATE_CALLBACK(c, s, r, w) \
do { \ do { \
if ((c)->sock_state_cb) { \ if ((c)->sock_state_cb) { \
ares__channel_unlock((c)); \
(c)->sock_state_cb((c)->sock_state_cb_data, (s), (r), (w)); \ (c)->sock_state_cb((c)->sock_state_cb_data, (s), (r), (w)); \
ares__channel_lock((c)); \
} \ } \
} while (0) } while (0)

14
src/lib/ares_search.c
Unescape View File

@ -82,7 +82,7 @@ static void ares_search_int(ares_channel_t *channel, const char *name,
return; return;
} }
if (s) { if (s) {
ares_query(channel, s, dnsclass, type, callback, arg); ares_query_qid(channel, s, dnsclass, type, callback, arg, NULL);
ares_free(s); ares_free(s);
return; return;
} }
@ -140,14 +140,14 @@ static void ares_search_int(ares_channel_t *channel, const char *name,
/* Try the name as-is first. */ /* Try the name as-is first. */
squery->next_domain = 0; squery->next_domain = 0;
squery->trying_as_is = ARES_TRUE; squery->trying_as_is = ARES_TRUE;
ares_query(channel, name, dnsclass, type, search_callback, squery); ares_query_qid(channel, name, dnsclass, type, search_callback, squery, NULL);
} else { } else {
/* Try the name as-is last; start with the first search domain. */ /* Try the name as-is last; start with the first search domain. */
squery->next_domain = 1; squery->next_domain = 1;
squery->trying_as_is = ARES_FALSE; squery->trying_as_is = ARES_FALSE;
status = ares__cat_domain(name, squery->domains[0], &s); status = ares__cat_domain(name, squery->domains[0], &s);
if (status == ARES_SUCCESS) { if (status == ARES_SUCCESS) {
ares_query(channel, s, dnsclass, type, search_callback, squery); ares_query_qid(channel, s, dnsclass, type, search_callback, squery, NULL);
ares_free(s); ares_free(s);
} else { } else {
/* failed, free the malloc()ed memory */ /* failed, free the malloc()ed memory */
@ -209,15 +209,15 @@ static void search_callback(void *arg, int status, int timeouts,
} else { } else {
squery->trying_as_is = ARES_FALSE; squery->trying_as_is = ARES_FALSE;
squery->next_domain++; squery->next_domain++;
ares_query(channel, s, squery->dnsclass, squery->type, search_callback, ares_query_qid(channel, s, squery->dnsclass, squery->type,
squery); search_callback, squery, NULL);
ares_free(s); ares_free(s);
} }
} else if (squery->status_as_is == -1) { } else if (squery->status_as_is == -1) {
/* Try the name as-is at the end. */ /* Try the name as-is at the end. */
squery->trying_as_is = ARES_TRUE; squery->trying_as_is = ARES_TRUE;
ares_query(channel, squery->name, squery->dnsclass, squery->type, ares_query_qid(channel, squery->name, squery->dnsclass, squery->type,
search_callback, squery); search_callback, squery, NULL);
} else { } else {
if (squery->status_as_is == ARES_ENOTFOUND && squery->ever_got_nodata) { if (squery->status_as_is == ARES_ENOTFOUND && squery->ever_got_nodata) {
end_squery(squery, ARES_ENODATA, NULL, 0); end_squery(squery, ARES_ENODATA, NULL, 0);

16
src/lib/ares_update_servers.c
Unescape View File

@ -703,8 +703,6 @@ ares_status_t ares__servers_update(ares_channel_t *channel,
return ARES_EFORMERR; return ARES_EFORMERR;
} }
ares__channel_lock(channel);
/* NOTE: a NULL or zero entry server list is considered valid due to /* NOTE: a NULL or zero entry server list is considered valid due to
* real-world people needing support for this for their test harnesses * real-world people needing support for this for their test harnesses
*/ */
@ -773,7 +771,6 @@ ares_status_t ares__servers_update(ares_channel_t *channel,
status = ARES_SUCCESS; status = ARES_SUCCESS;
done: done:
ares__channel_unlock(channel);
return status; return status;
} }
@ -1044,8 +1041,9 @@ int ares_set_servers(ares_channel_t *channel,
return (int)status; return (int)status;
} }
/* NOTE: lock is in ares__servers_update() */ ares__channel_lock(channel);
status = ares__servers_update(channel, slist, ARES_TRUE); status = ares__servers_update(channel, slist, ARES_TRUE);
ares__channel_unlock(channel);
ares__llist_destroy(slist); ares__llist_destroy(slist);
@ -1067,8 +1065,9 @@ int ares_set_servers_ports(ares_channel_t *channel,
return (int)status; return (int)status;
} }
/* NOTE: lock is in ares__servers_update() */ ares__channel_lock(channel);
status = ares__servers_update(channel, slist, ARES_TRUE); status = ares__servers_update(channel, slist, ARES_TRUE);
ares__channel_unlock(channel);
ares__llist_destroy(slist); ares__llist_destroy(slist);
@ -1086,8 +1085,6 @@ static ares_status_t set_servers_csv(ares_channel_t *channel, const char *_csv)
return ARES_ENODATA; return ARES_ENODATA;
} }
/* NOTE: lock is in ares__servers_update() */
if (ares_strlen(_csv) == 0) { if (ares_strlen(_csv) == 0) {
/* blank all servers */ /* blank all servers */
return (ares_status_t)ares_set_servers_ports(channel, NULL); return (ares_status_t)ares_set_servers_ports(channel, NULL);
@ -1099,8 +1096,9 @@ static ares_status_t set_servers_csv(ares_channel_t *channel, const char *_csv)
return status; return status;
} }
/* NOTE: lock is in ares__servers_update() */ ares__channel_lock(channel);
status = ares__servers_update(channel, slist, ARES_TRUE); status = ares__servers_update(channel, slist, ARES_TRUE);
ares__channel_unlock(channel);
ares__llist_destroy(slist); ares__llist_destroy(slist);
@ -1110,13 +1108,11 @@ static ares_status_t set_servers_csv(ares_channel_t *channel, const char *_csv)
/* We'll go ahead and honor ports anyhow */ /* We'll go ahead and honor ports anyhow */
int ares_set_servers_csv(ares_channel_t *channel, const char *_csv) int ares_set_servers_csv(ares_channel_t *channel, const char *_csv)
{ {
/* NOTE: lock is in ares__servers_update() */
return (int)set_servers_csv(channel, _csv); return (int)set_servers_csv(channel, _csv);
} }
int ares_set_servers_ports_csv(ares_channel_t *channel, const char *_csv) int ares_set_servers_ports_csv(ares_channel_t *channel, const char *_csv)
{ {
/* NOTE: lock is in ares__servers_update() */
return (int)set_servers_csv(channel, _csv); return (int)set_servers_csv(channel, _csv);
} }

Write Preview
Loading…
Cancel
Save