network: clean up address printing

clang-analyzer complains about sockaddr_storage being uninitalized, so
we zero that out first. Then, while we're at it, we use the right
constants for getnameinfo output sizes, and note the fact that the null
byte is part of snprintf's calculations.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Author: zx2c4

network.c

@@ -37,7 +37,8 @@
 
 char *print_addr_port(const struct sockaddr *addr, socklen_t addrlen)
 {
-    static char buf[1100], address[1025], port[32];
+    static char buf[NI_MAXHOST + NI_MAXSERV + 4];
+    char address[NI_MAXHOST], port[NI_MAXSERV];
     int err;
 
     err = getnameinfo(addr, addrlen, address, sizeof(address),
@@ -48,9 +49,9 @@ char *print_addr_port(const struct sockaddr *addr, socklen_t addrlen)
 	log_printf_exit(1, log_err, "getnameinfo: %s", gai_strerror(err));
 
     if (addr->sa_family == AF_INET6)
-	snprintf(buf, sizeof(buf) - 1, "[%s]:%s", address, port);
+	snprintf(buf, sizeof(buf), "[%s]:%s", address, port);
     else
-	snprintf(buf, sizeof(buf) - 1, "%s:%s", address, port);
+	snprintf(buf, sizeof(buf), "%s:%s", address, port);
 
     return buf;
 }
@@ -262,7 +263,7 @@ int accept_connections(int listening_sockets[])
 
 	for (i = 0; listening_sockets[i] != -1; i++) {
 	    int listen_sock;
-	    struct sockaddr_storage client_addr;
+	    struct sockaddr_storage client_addr = { 0 };
 	    socklen_t addrlen = sizeof(client_addr);
 
 	    if (!FD_ISSET(listening_sockets[i], &readfds))