fix possible fd leak, unrestored cancellation state on dns socket fail

[musl] / src / network / res_msend.c

diff --git a/src/network/res_msend.c b/src/network/res_msend.c
index 0ee914d..3e01800 100644 (file)
--- a/src/network/res_msend.c
+++ b/src/network/res_msend.c
@@ -27,8 +27,9 @@ static unsigned long mtime()
                + ts.tv_nsec / 1000000;
 }
 
-int __res_msend(int nqueries, const unsigned char *const *queries,
-       const int *qlens, unsigned char *const *answers, int *alens, int asize)
+int __res_msend_rc(int nqueries, const unsigned char *const *queries,
+       const int *qlens, unsigned char *const *answers, int *alens, int asize,
+       const struct resolvconf *conf)
 {
        int fd;
        int timeout, attempts, retry_interval, servfail_retry;
@@ -45,19 +46,14 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
        int cs;
        struct pollfd pfd;
        unsigned long t0, t1, t2;
-       struct resolvconf conf;
 
        pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
 
-       /* Get nameservers & timeout/retry settings from resolv.conf */
-       if (__get_resolv_conf(&conf, 0, 0) < 0) return -1;
+       timeout = 1000*conf->timeout;
+       attempts = conf->attempts;
 
-       timeout = 1000*conf.timeout;
-       attempts = conf.attempts;
-
-       nns = conf.nns;
-       for (nns=0; nns<conf.nns; nns++) {
-               struct address *iplit = &conf.ns[nns];
+       for (nns=0; nns<conf->nns; nns++) {
+               const struct address *iplit = &conf->ns[nns];
                if (iplit->family == AF_INET) {
                        memcpy(&ns[nns].sin.sin_addr, iplit->addr, 4);
                        ns[nns].sin.sin_port = htons(53);
@@ -80,7 +76,11 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
                fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
                family = AF_INET;
        }
-       if (fd < 0 || bind(fd, (void *)&sa, sl) < 0) return -1;
+       if (fd < 0 || bind(fd, (void *)&sa, sl) < 0) {
+               if (fd >= 0) close(fd);
+               pthread_setcancelstate(cs, 0);
+               return -1;
+       }
 
        /* Past this point, there are no errors. Each individual query will
         * yield either no reply (indicated by zero length) or an answer
@@ -178,3 +178,11 @@ out:
 
        return 0;
 }
+
+int __res_msend(int nqueries, const unsigned char *const *queries,
+       const int *qlens, unsigned char *const *answers, int *alens, int asize)
+{
+       struct resolvconf conf;
+       if (__get_resolv_conf(&conf, 0, 0) < 0) return -1;
+       return __res_msend_rc(nqueries, queries, qlens, answers, alens, asize, &conf);
+}