add ERP error macro to catch all those errors that will never happen

3 files changed, 22 insertions, 31 deletions

diff --git a/src/broadcaster.c b/src/broadcaster.c
index 2f0e194..bd80a5c 100644
--- a/src/broadcaster.c
+++ b/src/broadcaster.c
@@ -29,10 +29,7 @@ int main(int argc, char **argv)
       while ((MAXBUFLEN-total_len > 0)
 	     && ((i = read(0, &(buf[total_len]), MAXBUFLEN-total_len)) > 0))
 	total_len += i;
-      if (i < 0) {
-	perror("read(stdin)");
-	exit(1);
-      }
+      ENP(i, "read(stdin)");
     }else{
       /* use cmd line for payload */
       total_len += strlen(message);
@@ -45,11 +42,7 @@ int main(int argc, char **argv)
     }
 
     /* setup socket */
-    if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) == -1) {
-        perror("socket");
-        exit(1);
-    }
-
+    ENP((fd = socket(AF_INET6, SOCK_DGRAM, 0)), "socket");
     addr.sin6_family = AF_INET6;
     addr.sin6_port = htons(SERVERPORT);
     addr.sin6_flowinfo = 0;
@@ -60,10 +53,8 @@ int main(int argc, char **argv)
     }
 
     /* send packet */
-    if (sendto(fd, buf, total_len, 0, (struct sockaddr *)&addr, sizeof addr) == -1) {
-        perror("sendto");
-        exit(1);
-    }
+    ENP(sendto(fd, buf, total_len, 0, (struct sockaddr *) &addr, sizeof addr), 
+	"sendto");
 
     return 0;
 }
diff --git a/src/common.h b/src/common.h
index 0274856..5f24e57 100644
--- a/src/common.h
+++ b/src/common.h
@@ -14,4 +14,10 @@
 #define SERVERPORT_S "4950"
 #define MAXBUFLEN 100
 
+#define ENP(Cmd, Msg) \
+  if ((Cmd) == -1) {		\
+    perror(Msg);		\
+    exit(1);			\
+  }
+
 #endif // UDP_BROADCAST_COMMON
diff --git a/src/listener.c b/src/listener.c
index 020b90e..eb2950e 100644
--- a/src/listener.c
+++ b/src/listener.c
@@ -19,10 +19,7 @@ int main(int argc, char **argv, char **envp) {
       fprintf(stderr, "usage: %s [interface]\n", argv[0]);
       exit(1);
     }
-    if ((fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
-      perror("listener: socket");
-      exit(1);
-    }
+    ENP((fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP)), "listener: socket");
     if (argc == 2) {
       inet_pton(AF_INET6, "ff02::1", &(ba.sin6_addr));
       if ((ba.sin6_scope_id = if_nametoindex(argv[1])) == 0) {
@@ -36,17 +33,14 @@ int main(int argc, char **argv, char **envp) {
     ba.sin6_family = AF_INET6;
     ba.sin6_port = htons(SERVERPORT);
     ba.sin6_flowinfo = 0;
-    if (bind(fd, (struct sockaddr*) &ba, sizeof ba) != 0) {
-      perror("listener: bind");
-      exit(1);
-    }
+    ENP(bind(fd, (struct sockaddr*) &ba, sizeof ba), "listener: bind");
   }
 
   /* daemonize */
 #ifndef DEBUG
   switch (fork()) {
   case 0:
-    setsid();
+    ENP(setsid(), "setsid");
     umask(0);
     break;
   case -1:
@@ -76,10 +70,10 @@ int main(int argc, char **argv, char **envp) {
     switch (fork()) {
     case 0:
       /* redirect payload to stdio, leave stdout/err, close the rest */
-      dup(fd_payload[0], 1);
-      close(fd_payload[0]);
-      close(fd_payload[1]);
-      close(fd);
+      ENP(dup(fd_payload[0], 1), "dup");
+      ENP(close(fd_payload[0]),  "close");
+      ENP(close(fd_payload[1]),  "close");
+      ENP(close(fd),             "close");
 
       /* run our task task */
       execve(task, cl_argv, envp);
@@ -89,18 +83,18 @@ int main(int argc, char **argv, char **envp) {
       perror("fork");
       exit(1);
     default:
-      wait();
+      ENP(wait(), "wait");
     }
 
-    /* write payload to child process */
+    /* write payload to child process; the return value of write is
+       intentionally ignored */
     int tasklen = strlen(task);
     if (tasklen < numbytes)
       write(fd_payload[1], buf + tasklen + 1, numbytes - tasklen - 1);
-    close(fd_payload[1]);
-    close(fd_payload[0]);
+    ENP(close(fd_payload[1]), "close");
+    ENP(close(fd_payload[0]), "close");
   }
     
   perror("recvfrom");
-    
   return 1;
 }