[PATCH] Various fixes for resolve_host, from src/c/api/libspeechd.c.

[Christopher Brannon]

* Check return values of malloc and inet_ntop.  Do not proceed if they
are NULL.
* Store the return value of inet_ntop in a const char * variable, since
the function returns a pointer to constant data.
* Free allocated memory on errors.

Thanks to Andrei Kholodnyi for spotting my mistakes.
---
 src/c/api/libspeechd.c |   23 +++++++++++++++++++----
 1 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/c/api/libspeechd.c b/src/c/api/libspeechd.c
index 5d4a65a..ede727c 100644
--- a/src/c/api/libspeechd.c
+++ b/src/c/api/libspeechd.c
@@ -247,29 +247,44 @@ resolve_host(char* host_name_or_ip, int *is_localhost, 
gchar **error)
 {
     struct addrinfo *addr_result;
     int err;
-    char *resolved_ip = malloc(MAX_IP_SIZE*sizeof(char));
+    char *resolve_buffer = malloc(MAX_IP_SIZE*sizeof(char));
+    const char *resolved_ip = NULL;
     char *ip;
     *error = NULL;
     struct sockaddr_in *addr_in;
     
+    if (resolve_buffer == NULL) {
+       *error = g_strdup("Failed to allocate memory.");
+       return NULL;
+    }
+
     err = getaddrinfo(host_name_or_ip, 0, NULL, &addr_result);
     if (err){
        *error = g_strdup_printf("Can't resolve address %d due to error %s:",
                                 err, gai_strerror(err));
+       xfree(resolve_buffer);
        return NULL;
     }
     /* Take the first address returned as we are only interested in host ip */
     addr_in = (struct sockaddr_in *) addr_result->ai_addr;
-    resolved_ip = inet_ntop(AF_INET, &(addr_in->sin_addr.s_addr), resolved_ip, 
MAX_IP_SIZE);
+    resolved_ip = inet_ntop(AF_INET, &(addr_in->sin_addr.s_addr), 
resolve_buffer, MAX_IP_SIZE);
+    if (resolved_ip == NULL) {
+       *error = g_strdup_printf("Could not convert address, due to the 
following error: %s",
+                                strerror(errno));
+       freeaddrinfo(addr_result);
+       xfree(resolve_buffer);
+       return NULL;
+    }
+
     if (!strncmp(resolved_ip, "127.",4)){
        *is_localhost = 1;
        /* In case of local addresses, use 127.0.0.1 which is guaranteed
           to be local and the server listens on it */
-       xfree(resolved_ip);
+       xfree(resolve_buffer);
        ip = strdup("127.0.0.1");
     }else{
        *is_localhost = 0;
-       return ip = resolved_ip;
+       ip = resolve_buffer;
     }
     freeaddrinfo(addr_result);
     return ip;
-- 
1.7.2.2