Avoid freeaddrinfo(NULL)

Found by: Release_ Patch by: michaelortmann Fixes: #1329 The behavior of freeadrinfo(NULL) is left unspecified by RFC 3493. Some Operating Systems like FreeBSD handle this for compatibility / portability but others like OpenBSD do not (as reported in #1329), so let eggdrop avoid calling freeadrinfo(NULL).
eggheads · Oct 5, 2022 · 55595ab · 55595ab
1 parent b3b658b
commit 55595ab
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Showing 2 changed files with 31 additions and 16 deletions.
diff --git a/src/dns.c b/src/dns.c
@@ -503,6 +503,7 @@ void *thread_dns_hostbyip(void *arg)
   i = getnameinfo((const struct sockaddr *) &addr->addr.sa, addr->addrlen,
                   dtn->host, sizeof dtn->host, NULL, 0, 0);
   if (i) {
+    debug1("dns: thread_dns_hostbyip(): getnameinfo(): error = %s", gai_strerror(i));
 #ifdef IPV6
     if (addr->family == AF_INET6)
       inet_ntop(AF_INET6, &addr->addr.s6.sin6_addr, dtn->host, sizeof dtn->host);
@@ -520,13 +521,13 @@ void *thread_dns_hostbyip(void *arg)
 void *thread_dns_ipbyhost(void *arg)
 {
   struct dns_thread_node *dtn = (struct dns_thread_node *) arg;
-  struct addrinfo *res0, *res;
-  int i;
+  struct addrinfo *res0 = NULL, *res;
+  int error;
   sockname_t *addr = &dtn->addr;
 
-  i = getaddrinfo(dtn->host, NULL, NULL, &res0);
+  error = getaddrinfo(dtn->host, NULL, NULL, &res0);
   memset(addr, 0, sizeof *addr);
-  if (!i) {
+  if (!error) {
 #ifdef IPV6
     for (res = res0; res; res = res->ai_next) {
       if (res == res0 || res->ai_family == (pref_af ? AF_INET6 : AF_INET)) {
@@ -538,21 +539,27 @@ void *thread_dns_ipbyhost(void *arg)
       }
     }
 #else
-    i = 1;
+    error = 1;
     for (res = res0; res; res = res->ai_next) {
       if (res->ai_family == AF_INET) {
         addr->family = res->ai_family;
         addr->addrlen = res->ai_addrlen;
         memcpy(&addr->addr.sa, res->ai_addr, res->ai_addrlen);
-        i = 0;
+        error = 0;
         break;
       }
     }
 #endif
-    freeaddrinfo(res0);
+    if (res0) /* The behavior of freeadrinfo(NULL) is left unspecified by RFCs
+               * 2553 and 3493. Avoid to be compatible with all OSes. */
+      freeaddrinfo(res0);
   }
+  else if (error == EAI_NONAME)
+    debug1("dns: thread_dns_ipbyhost(): getaddrinfo(): hostname %s not known", dtn->host);
+  else
+    debug1("dns: thread_dns_ipbyhost(): getaddrinfo(): error = %s", gai_strerror(error));
   pthread_mutex_lock(&dtn->mutex);
-  dtn->ok = !i;
+  dtn->ok = !error;
   close(dtn->fildes[1]);
   pthread_mutex_unlock(&dtn->mutex);
   return NULL;
@@ -661,7 +668,7 @@ void core_dns_hostbyip(sockname_t *addr)
                       sizeof (struct sockaddr_in), host, sizeof host, NULL, 0, 0);
       alarm(0);
       if (i)
-        debug1("dns: getnameinfo(): error = %s", gai_strerror(i));
+        debug1("dns: core_dns_hostbyip(): getnameinfo(): error = %s", gai_strerror(i));
     }
     if (i)
       inet_ntop(AF_INET, &addr->addr.s4.sin_addr.s_addr, host, sizeof host);
@@ -673,7 +680,7 @@ void core_dns_hostbyip(sockname_t *addr)
                       sizeof (struct sockaddr_in6), host, sizeof host, NULL, 0, 0);
       alarm(0);
       if (i)
-        debug1("dns: getnameinfo(): error = %s", gai_strerror(i));
+        debug1("dns: core_dns_hostbyip(): getnameinfo(): error = %s", gai_strerror(i));
     }
     if (i)
       inet_ntop(AF_INET6, &addr->addr.s6.sin6_addr, host, sizeof host);

diff --git a/src/tcldcc.c b/src/tcldcc.c
@@ -1028,13 +1028,12 @@ static int tcl_connect STDVAR
 }
 
 static int setlisten(Tcl_Interp *irp, char *ip, char *portp, char *type, char *maskproc, char *flag) {
-  int i, idx = -1, port, realport, found=0, ipv4=1;
+  int i, idx = -1, port, realport, found=0, ipv4=1, error;
   char s[11], msg[256], newip[EGG_INET_ADDRSTRLEN];
   struct portmap *pmap = NULL, *pold = NULL;
   sockname_t name;
   struct in_addr ipaddr4;
   struct addrinfo hint, *ipaddr = NULL;
-  int ret;
 #ifdef IPV6
   struct in6_addr ipaddr6;
 #endif
@@ -1056,8 +1055,8 @@ static int setlisten(Tcl_Interp *irp, char *ip, char *portp, char *type, char *m
     strlcpy(newip, ip, sizeof newip);
   }
   /* Return addrinfo struct ipaddr containing family... */
-  ret = getaddrinfo(newip, NULL, &hint, &ipaddr);
-  if (!ret) {
+  error = getaddrinfo(newip, NULL, &hint, &ipaddr);
+  if (!error) {
   /* Load network address to in(6)_addr struct for later byte comparisons */
     if (ipaddr->ai_family == AF_INET) {
       inet_pton(AF_INET, newip, &ipaddr4);
@@ -1068,8 +1067,17 @@ static int setlisten(Tcl_Interp *irp, char *ip, char *portp, char *type, char *m
       ipv4 = 0;
     }
 #endif
+    if (ipaddr) /* The behavior of freeadrinfo(NULL) is left unspecified by RFCs
+                 * 2553 and 3493. Avoid to be compatible with all OSes. */
+      freeaddrinfo(ipaddr);
   }
-  freeaddrinfo(ipaddr);
+  else if (error == EAI_NONAME)
+    /* currently setlisten() handles only ip not hostname */
+    putlog(LOG_MISC, "*",
+           "tcldcc: setlisten(): getaddrinfo(): ip %s not known", newip);
+  else
+    putlog(LOG_MISC, "*", "tcldcc: setlisten(): getaddrinfo(): error = %s",
+           gai_strerror(error));
   port = realport = atoi(portp);
   for (pmap = root; pmap; pold = pmap, pmap = pmap->next) {
     if (pmap->realport == port) {
@@ -1282,7 +1290,7 @@ static int tcl_listen STDVAR
       strlcpy(ip, argv[1], sizeof(ip));
       i++;
     } else {
-      Tcl_AppendResult(irp, "invalid ip address", NULL);
+      Tcl_AppendResult(irp, "invalid IP address argument", NULL);
       return TCL_ERROR;
     }
   }