sg: accept -1 as argument to --port

* src/sg-cl.opt (--port option): Accept -1
* src/sg.c (str2port): Likewise.
(add_source_cidr): Fix coredump

2 files changed, 8 insertions, 7 deletions

diff --git a/src/sg-cl.opt b/src/sg-cl.opt
index d361d00..6b223b2 100644
--- a/src/sg-cl.opt
+++ b/src/sg-cl.opt
@@ -89,7 +89,7 @@ OPTION(port,P,[<PORT[-PORT]>],
        [<destination port number or range>])
 BEGIN
 	char *p = strchr(optarg, '-');
-        if (p) {
+        if (p && p > optarg) {
 		*p++ = 0;
 		to_port = p;
 	} else
diff --git a/src/sg.c b/src/sg.c
index c8e6af1..a1842c3 100644
--- a/src/sg.c
+++ b/src/sg.c
@@ -99,16 +99,17 @@ add_source_cidr(char *str, int i)
 	if (pe)
 		hints.ai_protocol = pe->p_proto;
 	else {
+		char *q;
 		errno = 0;
-		n = strtoul(proto, &p, 0);
-		if (errno || *p)
+		n = strtoul(proto, &q, 0);
+		if (errno || *q)
 			die(EX_USAGE, "%s: unrecognized protocol");
 		hints.ai_protocol = n;
 	}
 	hints.ai_family = AF_INET;
 		
 	if (getaddrinfo(str, NULL, &hints, &res)) {
-		p[-1] = '/';
+		if (p) p[-1] = '/';
 		die(EX_USAGE, "invalid network address in %s", str);
 	}
 
@@ -133,7 +134,7 @@ add_source_cidr(char *str, int i)
 static char *
 str2port(const char *str, char **pbuf, size_t *psize)
 {
-	unsigned long n;
+	long n;
 	struct servent *p;
 	char *end;
 	
@@ -144,12 +145,12 @@ str2port(const char *str, char **pbuf, size_t *psize)
 	}
 	
 	errno = 0;
-	n = strtoul(str, &end, 10);
+	n = strtol(str, &end, 10);
 	if (errno)
 		die(EX_USAGE, "%s: invalid port: %s", str, strerror(errno));
 	if (*end)
 		die(EX_USAGE, "%s: invalid port", str);
-	if (n > USHRT_MAX)
+	if (n < -1 || n > USHRT_MAX)
 		die(EX_USAGE, "%s: port number out of range", str);
 	return (char *) str;
 }