From 3805650736846c4e46cad85107dd81a70515ec11 Mon Sep 17 00:00:00 2001
From: Andrew Bettison <andrew@servalproject.org>
Date: Fri, 22 Nov 2013 11:54:32 +1030
Subject: [PATCH] Use ssize_t for sendto(2) return value, not int

Also improve error checking on ssize_t values (use ==-1 not <0) test
and cast ssize_t to size_t for comparisons
---
 mdp_client.c        |  4 ++--
 overlay_interface.c |  8 ++++----
 overlay_mdp.c       | 21 +++++++++------------
 3 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/mdp_client.c b/mdp_client.c
index b8ef160e..c7231903 100644
--- a/mdp_client.c
+++ b/mdp_client.c
@@ -122,7 +122,7 @@ int overlay_mdp_send(int mdp_sockfd, overlay_mdp_frame *mdp, int flags, int time
     return -1;
   // Minimise frame length to save work and prevent accidental disclosure of memory contents.
   ssize_t len = overlay_mdp_relevant_bytes(mdp);
-  if (len < 0)
+  if (len == -1)
     return WHY("MDP frame invalid (could not compute length)");
   /* Construct name of socket to send to. */
   struct sockaddr_un addr;
@@ -131,7 +131,7 @@ int overlay_mdp_send(int mdp_sockfd, overlay_mdp_frame *mdp, int flags, int time
     return -1;
   // Send to that socket
   set_nonblock(mdp_sockfd);
-  int result = sendto(mdp_sockfd, mdp, len, 0, (struct sockaddr *)&addr, addrlen);
+  ssize_t result = sendto(mdp_sockfd, mdp, (size_t)len, 0, (struct sockaddr *)&addr, addrlen);
   set_block(mdp_sockfd);
   if (result == -1) {
     mdp->packetTypeAndFlags=MDP_ERROR;
diff --git a/overlay_interface.c b/overlay_interface.c
index 55b547de..f71f4208 100644
--- a/overlay_interface.c
+++ b/overlay_interface.c
@@ -976,12 +976,12 @@ int overlay_broadcast_ensemble(struct network_destination *destination, struct o
     case SOCK_DGRAM:
     {
       if (config.debug.overlayinterfaces) 
-	DEBUGF("Sending %d byte overlay frame on %s to %s",len,interface->name,inet_ntoa(destination->address.sin_addr));
-      int sent=sendto(interface->alarm.poll.fd, 
-		bytes, len, 0, 
+	DEBUGF("Sending %zu byte overlay frame on %s to %s", (size_t)len, interface->name, inet_ntoa(destination->address.sin_addr));
+      ssize_t sent = sendto(interface->alarm.poll.fd, 
+		bytes, (size_t)len, 0, 
 		(struct sockaddr *)&destination->address, sizeof(destination->address));
       ob_free(buffer);
-      if (sent!= len){
+      if (sent == -1 || (size_t)sent != (size_t)len) {
 	WHYF_perror("sendto(fd=%d,len=%zu,addr=%s)",
 	    interface->alarm.poll.fd,
 	    (size_t)len,
diff --git a/overlay_mdp.c b/overlay_mdp.c
index 03c0a794..9ad5dfdd 100644
--- a/overlay_mdp.c
+++ b/overlay_mdp.c
@@ -154,19 +154,16 @@ int overlay_mdp_reply_error(int sock,
 int overlay_mdp_reply(int sock,struct sockaddr_un *recvaddr, socklen_t recvaddrlen,
 			  overlay_mdp_frame *mdpreply)
 {
-  if (!recvaddr) return WHY("No reply address");
-
+  if (!recvaddr)
+    return WHY("No reply address");
   ssize_t replylen = overlay_mdp_relevant_bytes(mdpreply);
-  if (replylen<0) return WHY("Invalid MDP frame (could not compute length)");
-
-  errno=0;
-  int r=sendto(sock,(char *)mdpreply,replylen,0,
-	       (struct sockaddr *)recvaddr,recvaddrlen);
-  if (r<replylen) { 
+  if (replylen == -1)
+    return WHY("Invalid MDP frame (could not compute length)");
+  ssize_t r = sendto(sock, (char *)mdpreply, (size_t)replylen, 0, (struct sockaddr *)recvaddr, recvaddrlen);
+  if (r == -1 || (size_t)r < (size_t)replylen) { 
     WHYF_perror("sendto(fd=%d,len=%zu,addr=%s)", sock, (size_t)replylen, alloca_sockaddr((struct sockaddr *)recvaddr, recvaddrlen));
     return WHYF("sendto() failed when sending MDP reply, sock=%d, r=%d", sock, r); 
-  } else
-    if (0) DEBUGF("reply of %d bytes sent",r);
+  }
   return 0;  
 }
 
@@ -450,8 +447,8 @@ static int overlay_saw_mdp_frame(struct overlay_frame *frame, overlay_mdp_frame
       if (len < 0)
 	RETURN(WHY("unsupported MDP packet type"));
       socklen_t addrlen = sizeof addr.sun_family + mdp_bindings[match].name_len;
-      int r = sendto(mdp_sock.poll.fd,mdp,len,0,(struct sockaddr*)&addr, addrlen);
-      if (r == len)
+      ssize_t r = sendto(mdp_sock.poll.fd, mdp, (size_t)len, 0, (struct sockaddr*)&addr, addrlen);
+      if ((size_t)r == (size_t)len)
 	RETURN(0);
       if (r == -1 && errno == ENOENT) {
 	/* far-end of socket has died, so drop binding */