fix some warnings reported by static analysis tool

iterate over environ via array-index notation with char **ptr on stack
(instead of repeatedly re-accessing global 'environ')

check getsockname() return values including addrlen

[mod_dirlisting] pass buf size into http_list_directory_sizefmt()

github: resolves #48

src/http-header-glue.c

@@ -140,7 +140,8 @@ int http_response_redirect_to_directory(server *srv, connection *con) {
 
 		our_addr_len = sizeof(our_addr);
 
-		if (-1 == getsockname(con->fd, &(our_addr.plain), &our_addr_len)) {
+		if (-1 == getsockname(con->fd, (struct sockaddr *)&our_addr, &our_addr_len)
+		    || our_addr_len > sizeof(our_addr)) {
 			con->http_status = 500;
 
 			log_error_write(srv, __FILE__, __LINE__, "ss",

src/mod_dirlisting.c

@@ -437,11 +437,11 @@ static void http_dirls_sort(dirls_entry_t **ent, int num) {
 /* buffer must be able to hold "999.9K"
  * conversion is simple but not perfect
  */
-static int http_list_directory_sizefmt(char *buf, off_t size) {
+static int http_list_directory_sizefmt(char *buf, size_t bufsz, off_t size) {
 	const char unit[] = "KMGTPE";	/* Kilo, Mega, Tera, Peta, Exa */
 	const char *u = unit - 1;		/* u will always increment at least once */
 	int remain;
-	char *out = buf;
+	size_t buflen;
 
 	if (size < 100)
 		size += 99;
@@ -465,14 +465,15 @@ static int http_list_directory_sizefmt(char *buf, off_t size) {
 		u++;
 	}
 
-	li_itostrn(out, 4, size);
-	out += strlen(out);
-	out[0] = '.';
-	out[1] = remain + '0';
-	out[2] = *u;
-	out[3] = '\0';
+	li_itostrn(buf, bufsz, size);
+	buflen = strlen(buf);
+	if (buflen + 3 >= bufsz) return buflen;
+	buf[buflen+0] = '.';
+	buf[buflen+1] = remain + '0';
+	buf[buflen+2] = *u;
+	buf[buflen+3] = '\0';
 
-	return (out + 3 - buf);
+	return buflen + 3;
 }
 
 static void http_list_directory_header(server *srv, connection *con, plugin_data *p, buffer *out) {
@@ -862,7 +863,7 @@ static int http_list_directory(server *srv, connection *con, plugin_data *p, buf
 #else
 		strftime(datebuf, sizeof(datebuf), "%Y-%b-%d %H:%M:%S", localtime(&(tmp->mtime)));
 #endif
-		http_list_directory_sizefmt(sizebuf, tmp->size);
+		http_list_directory_sizefmt(sizebuf, sizeof(sizebuf), tmp->size);
 
 		buffer_append_string_len(out, CONST_STR_LEN("<tr><td class=\"n\"><a href=\""));
 		buffer_append_string_encoded(out, DIRLIST_ENT_NAME(tmp), tmp->namelen, ENCODING_REL_URI_PART);

src/mod_fastcgi.c

@@ -1033,11 +1033,12 @@ static int fcgi_spawn_connection(server *srv,
 					}
 				}
 			} else {
-				for (i = 0; environ[i]; i++) {
+				char ** const e = environ;
+				for (i = 0; e[i]; ++i) {
 					char *eq;
 
-					if (NULL != (eq = strchr(environ[i], '='))) {
-						env_add(&env, environ[i], eq - environ[i], eq+1, strlen(eq+1));
+					if (NULL != (eq = strchr(e[i], '='))) {
+						env_add(&env, e[i], eq - e[i], eq+1, strlen(eq+1));
 					}
 				}
 			}
@@ -1926,7 +1927,8 @@ static int fcgi_create_env(server *srv, handler_ctx *hctx, size_t request_id) {
 	/* get the server-side of the connection to the client */
 	our_addr_len = sizeof(our_addr);
 
-	if (-1 == getsockname(con->fd, &(our_addr.plain), &our_addr_len)) {
+	if (-1 == getsockname(con->fd, (struct sockaddr *)&our_addr, &our_addr_len)
+	    || our_addr_len > sizeof(our_addr)) {
 		s = inet_ntop_cache_get_ip(srv, &(srv_sock->addr));
 	} else {
 		s = inet_ntop_cache_get_ip(srv, &(our_addr));

src/mod_scgi.c

@@ -825,11 +825,12 @@ static int scgi_spawn_connection(server *srv,
 					}
 				}
 			} else {
-				for (i = 0; environ[i]; i++) {
+				char ** const e = environ;
+				for (i = 0; e[i]; ++i) {
 					char *eq;
 
-					if (NULL != (eq = strchr(environ[i], '='))) {
-						env_add(&env, environ[i], eq - environ[i], eq+1, strlen(eq+1));
+					if (NULL != (eq = strchr(e[i], '='))) {
+						env_add(&env, e[i], eq - e[i], eq+1, strlen(eq+1));
 					}
 				}
 			}
@@ -1576,7 +1577,8 @@ static int scgi_create_env(server *srv, handler_ctx *hctx) {
 	/* get the server-side of the connection to the client */
 	our_addr_len = sizeof(our_addr);
 
-	if (-1 == getsockname(con->fd, &(our_addr.plain), &our_addr_len)) {
+	if (-1 == getsockname(con->fd, (struct sockaddr *)&our_addr, &our_addr_len)
+	    || our_addr_len > sizeof(our_addr)) {
 		s = inet_ntop_cache_get_ip(srv, &(srv_sock->addr));
 	} else {
 		s = inet_ntop_cache_get_ip(srv, &(our_addr));