fix uninitialized scopeid in lookups from hosts file and ip literals

[musl] / src / network / res_msend.c

diff --git a/src/network/res_msend.c b/src/network/res_msend.c
index cded535..35f106d 100644 (file)
--- a/src/network/res_msend.c
+++ b/src/network/res_msend.c
@@ -12,6 +12,7 @@
 #include <pthread.h>
 #include "stdio_impl.h"
 #include "syscall.h"
+#include "lookup.h"
 
 static void cleanup(void *p)
 {
@@ -33,7 +34,7 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
        FILE *f, _f;
        unsigned char _buf[256];
        char line[64], *s, *z;
-       int timeout = 5000, attempts = 2, retry_interval;
+       int timeout = 5000, attempts = 2, retry_interval, servfail_retry;
        union {
                struct sockaddr_in sin;
                struct sockaddr_in6 sin6;
@@ -47,6 +48,7 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
        int cs;
        struct pollfd pfd;
        unsigned long t0, t1, t2;
+       struct address iplit;
 
        pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
 
@@ -76,13 +78,18 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
                for (z=s; *z && !isspace(*z); z++);
                *z=0;
 
-               if (inet_pton(AF_INET, s, &ns[nns].sin.sin_addr)>0) {
-                       ns[nns].sin.sin_port = htons(53);
-                       ns[nns++].sin.sin_family = AF_INET;
-               } else if (inet_pton(AF_INET6, s, &ns[nns].sin6.sin6_addr)>0) {
-                       sl = sizeof sa.sin6;
-                       ns[nns].sin6.sin6_port = htons(53);
-                       ns[nns++].sin6.sin6_family = family = AF_INET6;
+               if (__lookup_ipliteral(&iplit, s, AF_UNSPEC)>0) {
+                       if (iplit.family == AF_INET) {
+                               memcpy(&ns[nns].sin.sin_addr, iplit.addr, 4);
+                               ns[nns].sin.sin_port = htons(53);
+                               ns[nns++].sin.sin_family = AF_INET;
+                       } else {
+                               sl = sizeof sa.sin6;
+                               memcpy(&ns[nns].sin6.sin6_addr, iplit.addr, 16);
+                               ns[nns].sin6.sin6_port = htons(53);
+                               ns[nns].sin6.sin6_scope_id = iplit.scopeid;
+                               ns[nns++].sin6.sin6_family = family = AF_INET6;
+                       }
                }
        }
        if (f) __fclose_ca(f);
@@ -131,6 +138,7 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
        pfd.fd = fd;
        pfd.events = POLLIN;
        retry_interval = timeout / attempts;
+       next = 0;
        t0 = t2 = mtime();
        t1 = t2 - retry_interval;
 
@@ -144,6 +152,7 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
                                                        qlens[i], MSG_NOSIGNAL,
                                                        (void *)&ns[j], sl);
                        t1 = t2;
+                       servfail_retry = 2 * nqueries;
                }
 
                /* Wait for a response, or until time to retry */
@@ -152,12 +161,12 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
                while ((rlen = recvfrom(fd, answers[next], asize, 0,
                  (void *)&sa, (socklen_t[1]){sl})) >= 0) {
 
-                       /* Ignore non-identifiable packets (no query id) */
-                       if (rlen < 2) continue;
+                       /* Ignore non-identifiable packets */
+                       if (rlen < 4) continue;
 
                        /* Ignore replies from addresses we didn't send to */
-                       for (i=0; i<nns && memcmp(ns+i, &sa, sl); i++);
-                       if (i==nns) continue;
+                       for (j=0; j<nns && memcmp(ns+j, &sa, sl); j++);
+                       if (j==nns) continue;
 
                        /* Find which query this answer goes with, if any */
                        for (i=next; i<nqueries && (
@@ -166,6 +175,22 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
                        if (i==nqueries) continue;
                        if (alens[i]) continue;
 
+                       /* Only accept positive or negative responses;
+                        * retry immediately on server failure, and ignore
+                        * all other codes such as refusal. */
+                       switch (answers[next][3] & 15) {
+                       case 0:
+                       case 3:
+                               break;
+                       case 2:
+                               if (servfail_retry && servfail_retry--)
+                                       sendto(fd, queries[i],
+                                               qlens[i], MSG_NOSIGNAL,
+                                               (void *)&ns[j], sl);
+                       default:
+                               continue;
+                       }
+
                        /* Store answer in the right slot, or update next
                         * available temp slot if it's already in place. */
                        alens[i] = rlen;