hostip: fix 3 coverity complaints

Follow-up to 1a0ebf6632f889eed

- Check the return code to Curl_inet_pton() in two instances, even
  though we know the input is valid so the functions won't fail.

- Clear the 'struct sockaddr_in' struct before use so that the
  'sin_zero' field isn't left uninitialized.

Detected by Coverity.
Assisted-by: Harry Sintonen
Closes #7163

1 files changed, 6 insertions, 3 deletions

diff --git a/lib/hostip.c b/lib/hostip.c
index 2a00c7d12..1832bee4d 100644
--- a/lib/hostip.c
+++ b/lib/hostip.c
@@ -479,7 +479,8 @@ static struct Curl_addrinfo *get_localhost6(int port)
   sa6.sin6_port = htons(port16);
   sa6.sin6_flowinfo = 0;
   sa6.sin6_scope_id = 0;
-  Curl_inet_pton(AF_INET6, "::1", ipv6);
+  if(Curl_inet_pton(AF_INET6, "::1", ipv6) < 1)
+    return NULL;
   memcpy(&sa6.sin6_addr, ipv6, sizeof(ipv6));
 
   ca->ai_flags     = 0;
@@ -511,9 +512,12 @@ static struct Curl_addrinfo *get_localhost(int port)
   if(!ca)
     return NULL;
 
+  /* memset to clear the sa.sin_zero field */
+  memset(&sa, 0, sizeof(sa));
   sa.sin_family = AF_INET;
   sa.sin_port = htons(port16);
-  Curl_inet_pton(AF_INET, "127.0.0.1", (char *)&ipv4);
+  if(Curl_inet_pton(AF_INET, "127.0.0.1", (char *)&ipv4) < 1)
+    return NULL;
   memcpy(&sa.sin_addr, &ipv4, sizeof(ipv4));
 
   ca->ai_flags     = 0;
@@ -521,7 +525,6 @@ static struct Curl_addrinfo *get_localhost(int port)
   ca->ai_socktype  = SOCK_STREAM;
   ca->ai_protocol  = IPPROTO_TCP;
   ca->ai_addrlen   = (curl_socklen_t)ss_size;
-  ca->ai_next      = NULL;
   ca->ai_addr = (void *)((char *)ca + sizeof(struct Curl_addrinfo));
   memcpy(ca->ai_addr, &sa, ss_size);
   ca->ai_canonname = (char *)ca->ai_addr + ss_size;