From 43ee4df3384853a9c53f4f45b31d190ff9b0d7f0 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Mon, 18 Apr 2011 21:35:14 -0400 Subject: [PATCH] dns lookups: protect against cancellation and fix incorrect error codes --- src/network/__dns.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/src/network/__dns.c b/src/network/__dns.c index b53ad4ab..b3c876f3 100644 --- a/src/network/__dns.c +++ b/src/network/__dns.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "__dns.h" #include "stdio_impl.h" @@ -42,14 +43,15 @@ int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt) struct timeval tv; fd_set fds; int id; + int cs; /* Construct query template - RR and ID will be filled later */ - if (strlen(name)-1 >= 254U) return -1; + if (strlen(name)-1 >= 254U) return EAI_NONAME; q[2] = q[5] = 1; strcpy((char *)q+13, name); for (i=13; q[i]; i=j+1) { for (j=i; q[j] && q[j] != '.'; j++); - if (j-i-1u > 62u) return -1; + if (j-i-1u > 62u) return EAI_NONAME; q[i-1] = j-i; } q[i+3] = 1; @@ -80,12 +82,14 @@ 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); if (bind(fd, (void *)&sa, sl) < 0) { - close(fd); - return -1; + errcode = EAI_SYSTEM; + goto out; } /* Nonblocking to work around Linux UDP select bug */ fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK); @@ -140,7 +144,9 @@ int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt) /* Check to see if we have answers to all queries */ if (got+failed == rrcnt) break; } +out: close(fd); + pthread_setcancelstate(cs, 0); /* Return the number of results, or an error code if none */ if (got) return got; -- 2.25.1