From 12d547b262c2c8c4e23d0a62eb59581929c2da89 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 21 Sep 2011 23:27:17 -0400 Subject: [PATCH] make dns lookups (and thus getaddrinfo) cancellable --- src/network/__dns.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/src/network/__dns.c b/src/network/__dns.c index a5458b51..8cd7d5d0 100644 --- a/src/network/__dns.c +++ b/src/network/__dns.c @@ -19,6 +19,11 @@ #define PACKET_MAX 512 #define PTR_MAX (64 + sizeof ".in-addr.arpa") +static void cleanup(void *p) +{ + close((intptr_t)p); +} + int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt) { time_t t0 = time(0); @@ -44,6 +49,8 @@ int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt) int id; int cs; + pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs); + /* Construct query template - RR and ID will be filled later */ if (strlen(name)-1 >= 254U) return EAI_NONAME; q[2] = q[5] = 1; @@ -81,8 +88,6 @@ int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt) sl = sizeof sa.sin; } - pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs); - /* Get local address and open/bind a socket */ sa.sin.sin_family = family; fd = socket(family, SOCK_DGRAM, 0); @@ -96,6 +101,9 @@ int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt) pfd.fd = fd; pfd.events = POLLIN; + pthread_cleanup_push(cleanup, (void *)(intptr_t)fd); + pthread_setcancelstate(cs, 0); + /* Loop until we timeout; break early on success */ for (; time(0)-t0 < TIMEOUT; ) { @@ -143,8 +151,7 @@ int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt) if (got+failed == rrcnt) break; } out: - close(fd); - pthread_setcancelstate(cs, 0); + pthread_cleanup_pop(1); /* Return the number of results, or an error code if none */ if (got) return got; -- 2.25.1