1 files changed, 123 insertions, 77 deletions

diff --git a/libntp/decodenetnum.c b/libntp/decodenetnum.c
index 35e839aafb09..8ff67625202c 100644
--- a/libntp/decodenetnum.c
+++ b/libntp/decodenetnum.c
@@ -13,106 +13,152 @@
 
 #include "ntp.h"
 #include "ntp_stdlib.h"
-#include "ntp_assert.h"
 
-#define PORTSTR(x) _PORTSTR(x)
-#define _PORTSTR(x) #x
 
-static int
-isnumstr(
-	const char *s
+/* If the given string position points to a decimal digit, parse the
+ * number. If this is not possible, or the parsing did not consume the
+ * whole string, or if the result exceeds the maximum value, return the
+ * default value.
+ */
+static unsigned long
+_num_or_dflt(
+	char *		sval,
+	unsigned long	maxval,
+	unsigned long	defval
 	)
 {
-	while (*s >= '0' && *s <= '9')
-		++s;
-	return !*s;
+	char *		ep;
+	unsigned long	num;
+	
+	if (!(sval && isdigit(*(unsigned char*)sval)))
+		return defval;
+	
+	num = strtoul(sval, &ep, 10);
+	if (!*ep && num <= maxval)
+		return num;
+	
+	return defval;
+}
+
+/* If the given string position is not NULL and does not point to the
+ * terminator, replace the character with NUL and advance the pointer.
+ * Return the resulting position.
+ */
+static inline char*
+_chop(
+	char * sp)
+{
+	if (sp && *sp)
+		*sp++ = '\0';
+	return sp;
+}
+
+/* If the given string position points to the given char, advance the
+ * pointer and return the result. Otherwise, return NULL.
+ */
+static inline char*
+_skip(
+	char * sp,
+	int    ch)
+{
+	if (sp && *(unsigned char*)sp == ch)
+		return (sp + 1);
+	return NULL;
 }
 
 /*
  * decodenetnum		convert text IP address and port to sockaddr_u
  *
- * Returns 0 for failure, 1 for success.
+ * Returns FALSE (->0) for failure, TRUE (->1) for success.
  */
 int
 decodenetnum(
 	const char *num,
-	sockaddr_u *netnum
+	sockaddr_u *net
 	)
 {
-	static const char * const servicename = "ntp";
-	static const char * const serviceport = PORTSTR(NTP_PORT);
+	/* Building a parser is more fun in Haskell, but here we go...
+	 *
+	 * This works through 'inet_pton()' taking the brunt of the
+	 * work, after some string manipulations to split off URI
+	 * brackets, ports and scope identifiers. The heuristics are
+	 * simple but must hold for all _VALID_ addresses. inet_pton()
+	 * will croak on bad ones later, but replicating the whole
+	 * parser logic to detect errors is wasteful.
+	 */
 	
-	struct addrinfo hints, *ai = NULL;
-	int err;
-	const char *host_str;
-	const char *port_str;
-	char *pp;
-	char *np;
-	char nbuf[80];
-
-	REQUIRE(num != NULL);
-
-	if (strlen(num) >= sizeof(nbuf)) {
-		printf("length error\n");
+	sockaddr_u	netnum;
+	char		buf[64];	/* working copy of input */
+	char		*haddr=buf;
+	unsigned int	port=NTP_PORT, scope=0;
+	unsigned short	afam=AF_UNSPEC;
+	
+	/* copy input to working buffer with length check */
+	if (strlcpy(buf, num, sizeof(buf)) >= sizeof(buf))
 		return FALSE;
-	}
 
-	port_str = servicename;
-	if ('[' != num[0]) {
-		/*
-		 * to distinguish IPv6 embedded colons from a port
-		 * specification on an IPv4 address, assume all 
-		 * legal IPv6 addresses have at least two colons.
-		 */
-		pp = strchr(num, ':');
-		if (NULL == pp)
-			host_str = num;	/* no colons */
-		else if (NULL != strchr(pp + 1, ':'))
-			host_str = num;	/* two or more colons */
-		else {			/* one colon */
-			strlcpy(nbuf, num, sizeof(nbuf));
-			host_str = nbuf;
-			pp = strchr(nbuf, ':');
-			*pp = '\0';
-			port_str = pp + 1;
+	/* Identify address family and possibly the port, if given.  If
+	 * this results in AF_UNSPEC, we will fail in the next step.
+	 */
+	if (*haddr == '[') {
+		char * endp = strchr(++haddr, ']');
+		if (endp) {
+			port = _num_or_dflt(_skip(_chop(endp), ':'),
+					      0xFFFFu, port);
+			afam = strchr(haddr, ':') ? AF_INET6 : AF_INET;
 		}
 	} else {
-		host_str = np = nbuf; 
-		while (*++num && ']' != *num)
-			*np++ = *num;
-		*np = 0;
-		if (']' == num[0] && ':' == num[1] && '\0' != num[2])
-			port_str = &num[2];
+		char *col = strchr(haddr, ':');
+		char *dot = strchr(haddr, '.');
+		if (col == dot) {
+			/* no dot, no colon: bad! */
+			afam = AF_UNSPEC;
+		} else if (!col) {
+			/* no colon, only dot: IPv4! */
+			afam = AF_INET;
+		} else if (!dot || col < dot) {
+			/* no dot or 1st colon before 1st dot: IPv6! */
+			afam = AF_INET6;
+		} else {
+			/* 1st dot before 1st colon: must be IPv4 with port */
+			afam = AF_INET;
+			port = _num_or_dflt(_chop(col), 0xFFFFu, port);
+		}
 	}
-	if ( ! *host_str)
+
+	/* Since we don't know about additional members in the address
+	 * structures, we wipe the result buffer thoroughly:
+	 */	 
+	memset(&netnum, 0, sizeof(netnum));
+
+	/* For AF_INET6, evaluate and remove any scope suffix. Have
+	 * inet_pton() do the real work for AF_INET and AF_INET6, bail
+	 * out otherwise:
+	 */
+	switch (afam) {
+	case AF_INET:
+		if (inet_pton(afam, haddr, &netnum.sa4.sin_addr) <= 0)
+			return FALSE;
+		netnum.sa4.sin_port = htons((unsigned short)port);
+		break;
+
+	case AF_INET6:
+		scope = _num_or_dflt(_chop(strchr(haddr, '%')), 0xFFFFFFFFu, scope);
+		if (inet_pton(afam, haddr, &netnum.sa6.sin6_addr) <= 0)
+			return FALSE;
+		netnum.sa6.sin6_port = htons((unsigned short)port);
+		netnum.sa6.sin6_scope_id = scope;
+		break;
+
+	case AF_UNSPEC:
+	default:
 		return FALSE;
-	if ( ! *port_str)
-		port_str = servicename;
-	
-	ZERO(hints);
-	hints.ai_flags |= Z_AI_NUMERICHOST;
-	if (isnumstr(port_str))
-		hints.ai_flags |= Z_AI_NUMERICSERV;
-	err = getaddrinfo(host_str, port_str, &hints, &ai);
-	/* retry with default service name if the service lookup failed */ 
-	if (err == EAI_SERVICE && strcmp(port_str, servicename)) {
-		hints.ai_flags &= ~Z_AI_NUMERICSERV;
-		port_str = servicename;
-		err = getaddrinfo(host_str, port_str, &hints, &ai);
 	}
-	/* retry another time with default service port if the service lookup failed */ 
-	if (err == EAI_SERVICE && strcmp(port_str, serviceport)) {
-		hints.ai_flags |= Z_AI_NUMERICSERV;
-		port_str = serviceport;
-		err = getaddrinfo(host_str, port_str, &hints, &ai);
-	}
-	if (err != 0)
-		return FALSE;
-
-	INSIST(ai->ai_addrlen <= sizeof(*netnum));
-	ZERO(*netnum);
-	memcpy(netnum, ai->ai_addr, ai->ai_addrlen);
-	freeaddrinfo(ai);
 
+	/* Collect the remaining pieces and feed the output, which was
+	 * not touched so far:
+	 */
+	netnum.sa.sa_family = afam;
+	memcpy(net, &netnum, sizeof(netnum));
 	return TRUE;
 }