From 7b8eeeceed5bf59b7e9558e1535f3012bb246375 Mon Sep 17 00:00:00 2001 From: Eric Andersen Date: Wed, 3 Apr 2002 11:50:50 +0000 Subject: Patch from Jim Treadway to eliminate use of alarm() and therefore SIGARLM in the resolver and to instead use select, which is much cleaner. --- libc/inet/resolv.c | 34 ++++++++++++---------------------- 1 file changed, 12 insertions(+), 22 deletions(-) (limited to 'libc') diff --git a/libc/inet/resolv.c b/libc/inet/resolv.c index 29094541a..ae99ea068 100644 --- a/libc/inet/resolv.c +++ b/libc/inet/resolv.c @@ -530,12 +530,6 @@ int form_query(int id, const char *name, int type, unsigned char *packet, #ifdef L_dnslookup -int dns_caught_signal = 0; -void dns_catch_signal(int signo) -{ - dns_caught_signal = 1; -} - int dns_lookup(const char *name, int type, int nscount, char **nsip, unsigned char **outpacket, struct resolv_answer *a) { @@ -546,8 +540,8 @@ int dns_lookup(const char *name, int type, int nscount, char **nsip, #ifdef __UCLIBC_HAS_IPV6__ struct sockaddr_in6 sa6; #endif /* __UCLIBC_HAS_IPV6__ */ - int oldalarm; - __sighandler_t oldhandler; + struct timeval tv; + fd_set fds; struct resolv_header h; struct resolv_question q; int retries = 0; @@ -652,23 +646,19 @@ int dns_lookup(const char *name, int type, int nscount, char **nsip, send(fd, packet, len, 0); - dns_caught_signal = 0; - oldalarm = alarm(REPLY_TIMEOUT); - oldhandler = signal(SIGALRM, dns_catch_signal); - - i = recv(fd, packet, PACKETSZ, 0); + FD_ZERO(&fds); + FD_SET(fd, &fds); + tv.tv_sec = REPLY_TIMEOUT; + tv.tv_usec = 0; + if (select(fd + 1, &fds, NULL, NULL, &tv) <= 0) { + DPRINTF("Timeout\n"); - alarm(0); - signal(SIGALRM, oldhandler); - alarm(oldalarm); - - DPRINTF("Timeout=%d, len=%d\n", dns_caught_signal, i); - - if (dns_caught_signal) - /* timed out, so retry send and receive, - to next nameserver on queue */ + /* timed out, so retry send and receive, + * to next nameserver on queue */ goto again; + } + i = recv(fd, packet, 512, 0); if (i < HFIXEDSZ) /* too short ! */ goto again; -- cgit v1.2.3