From 5f630cb3d2314fb0748b102665767f65ea65d848 Mon Sep 17 00:00:00 2001 From: Eric Andersen Date: Mon, 8 Jul 2002 01:38:22 +0000 Subject: Finer grained locking in __connect_dns() so we don't hold the lock while sending packets out onto the wire. -Erik --- libc/inet/resolv.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) (limited to 'libc') diff --git a/libc/inet/resolv.c b/libc/inet/resolv.c index f813b1273..177424d51 100644 --- a/libc/inet/resolv.c +++ b/libc/inet/resolv.c @@ -598,7 +598,7 @@ int __dns_lookup(const char *name, int type, int nscount, char **nsip, struct resolv_question q; int retries = 0; unsigned char * packet = malloc(PACKETSZ); - char * lookup = malloc(MAXDNAME); + char *dns, *lookup = malloc(MAXDNAME); int variant = 0; fd = -1; @@ -610,6 +610,7 @@ int __dns_lookup(const char *name, int type, int nscount, char **nsip, LOCK; ns %= nscount; + UNLOCK; while (retries++ < MAX_RETRIES) { if (fd != -1) @@ -618,7 +619,13 @@ int __dns_lookup(const char *name, int type, int nscount, char **nsip, memset(packet, 0, PACKETSZ); memset(&h, 0, sizeof(h)); + + /* Mess with globals while under lock */ + LOCK; h.id = ++id; + dns = nsip[ns]; + UNLOCK; + h.qdcount = 1; h.rd = 1; @@ -646,9 +653,9 @@ int __dns_lookup(const char *name, int type, int nscount, char **nsip, len = i + j; DPRINTF("On try %d, sending query to port %d of machine %s\n", - retries, NAMESERVER_PORT, nsip[ns]); + retries, NAMESERVER_PORT, dns); - fd = __connect_dns(nsip[ns]); + fd = __connect_dns(dns); if (fd < 0) { if (errno == ENETUNREACH) { /* routing error, presume not transient */ @@ -684,9 +691,14 @@ int __dns_lookup(const char *name, int type, int nscount, char **nsip, DPRINTF("id = %d, qr = %d\n", h.id, h.qr); - if ((h.id != id) || (!h.qr)) + LOCK; + if ((h.id != id) || (!h.qr)) { + UNLOCK; /* unsolicited */ goto again; + } + UNLOCK; + DPRINTF("Got response %s\n", "(i think)!"); DPRINTF("qrcount=%d,ancount=%d,nscount=%d,arcount=%d\n", @@ -738,7 +750,6 @@ int __dns_lookup(const char *name, int type, int nscount, char **nsip, else free(packet); free(lookup); - UNLOCK; return (0); /* success! */ tryall: @@ -755,13 +766,14 @@ int __dns_lookup(const char *name, int type, int nscount, char **nsip, variant++; } else { /* next server, first search */ + LOCK; ns = (ns + 1) % nscount; + UNLOCK; variant = 0; } } fail: - UNLOCK; if (fd != -1) close(fd); if (lookup) @@ -774,6 +786,7 @@ fail: #ifdef L_opennameservers +#warning fixme -- __nameserver, __nameservers, __searchdomain, and __searchdomains need locking int __nameservers; char * __nameserver[MAX_SERVERS]; int __searchdomains; -- cgit v1.2.3