iproute: fix parsing and matching of of "short" IP addrs like 10/8

function                                             old     new   delta
print_route                                         1613    1813    +200
get_addr_1                                           209     258     +49
get_prefix                                           393     356     -37
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 249/-37)           Total: 212 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

4 files changed, 74 insertions, 38 deletions

diff --git a/networking/libiproute/iproute.c b/networking/libiproute/iproute.c
index 393a376ac..f8a67d9ee 100644
--- a/networking/libiproute/iproute.c
+++ b/networking/libiproute/iproute.c
@@ -82,7 +82,7 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 {
 	struct rtmsg *r = NLMSG_DATA(n);
 	int len = n->nlmsg_len;
-	struct rtattr * tb[RTA_MAX+1];
+	struct rtattr *tb[RTA_MAX+1];
 	char abuf[256];
 	inet_prefix dst;
 	inet_prefix src;
@@ -159,8 +159,21 @@ static int FAST_FUNC print_route(const struct sockaddr_nl *who UNUSED_PARAM,
 	}
 
 	memset(tb, 0, sizeof(tb));
+	memset(&src, 0, sizeof(src));
+	memset(&dst, 0, sizeof(dst));
 	parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
 
+	if (tb[RTA_SRC]) {
+		src.bitlen = r->rtm_src_len;
+		src.bytelen = (r->rtm_family == AF_INET6 ? 16 : 4);
+		memcpy(src.data, RTA_DATA(tb[RTA_SRC]), src.bytelen);
+	}
+	if (tb[RTA_DST]) {
+		dst.bitlen = r->rtm_dst_len;
+		dst.bytelen = (r->rtm_family == AF_INET6 ? 16 : 4);
+		memcpy(dst.data, RTA_DATA(tb[RTA_DST]), dst.bytelen);
+	}
+
 	if (G_filter.rdst.family
 	 && inet_addr_match(&dst, &G_filter.rdst, G_filter.rdst.bitlen)
 	) {
@@ -426,7 +439,8 @@ IF_FEATURE_IP_RULE(ARG_table,)
 				NEXT_ARG();
 			}
 			if ((**argv < '0' || **argv > '9')
-			 && rtnl_rtntype_a2n(&type, *argv) == 0) {
+			 && rtnl_rtntype_a2n(&type, *argv) == 0
+			) {
 				NEXT_ARG();
 				req.r.rtm_type = type;
 				ok |= type_ok;
diff --git a/networking/libiproute/libnetlink.c b/networking/libiproute/libnetlink.c
index 547013ff6..c7533a4a7 100644
--- a/networking/libiproute/libnetlink.c
+++ b/networking/libiproute/libnetlink.c
@@ -393,7 +393,7 @@ void FAST_FUNC parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, in
 		if (rta->rta_type <= max) {
 			tb[rta->rta_type] = rta;
 		}
-		rta = RTA_NEXT(rta,len);
+		rta = RTA_NEXT(rta, len);
 	}
 	if (len) {
 		bb_error_msg("deficit %d, rta_len=%d!", len, rta->rta_len);
diff --git a/networking/libiproute/utils.c b/networking/libiproute/utils.c
index d32db8de5..d0fe30605 100644
--- a/networking/libiproute/utils.c
+++ b/networking/libiproute/utils.c
@@ -83,20 +83,43 @@ int get_addr_1(inet_prefix *addr, char *name, int family)
 		return 0;
 	}
 
-	addr->family = AF_INET;
 	if (family != AF_UNSPEC && family != AF_INET)
 		return -1;
+
+	/* Try to parse it as IPv4 */
+	addr->family = AF_INET;
+#if 0 /* Doesn't handle e.g. "10.10", for example, "ip r l root 10.10/16" */
 	if (inet_pton(AF_INET, name, addr->data) <= 0)
 		return -1;
+#else
+	{
+		unsigned i = 0;
+		unsigned n = 0;
+		const char *cp = name - 1;
+		while (*++cp) {
+			if ((unsigned char)(*cp - '0') <= 9) {
+				n = 10 * n + (unsigned char)(*cp - '0');
+				if (n >= 256)
+					return -1;
+				((uint8_t*)addr->data)[i] = n;
+				continue;
+			}
+			if (*cp == '.' && ++i <= 3) {
+				n = 0;
+				continue;
+			}
+			return -1;
+		}
+	}
+#endif
 	addr->bytelen = 4;
 	addr->bitlen = -1;
+
 	return 0;
 }
 
-static int get_prefix_1(inet_prefix *dst, char *arg, int family)
+static void get_prefix_1(inet_prefix *dst, char *arg, int family)
 {
-	int err;
-	unsigned plen;
 	char *slash;
 
 	memset(dst, 0, sizeof(*dst));
@@ -108,48 +131,50 @@ static int get_prefix_1(inet_prefix *dst, char *arg, int family)
 		dst->family = family;
 		/*dst->bytelen = 0; - done by memset */
 		/*dst->bitlen = 0;*/
-		return 0;
+		return;
 	}
 
 	slash = strchr(arg, '/');
 	if (slash)
 		*slash = '\0';
-	err = get_addr_1(dst, arg, family);
-	if (err == 0) {
+
+	if (get_addr_1(dst, arg, family) == 0) {
 		dst->bitlen = (dst->family == AF_INET6) ? 128 : 32;
 		if (slash) {
+			unsigned plen;
 			inet_prefix netmask_pfx;
 
 			netmask_pfx.family = AF_UNSPEC;
 			plen = bb_strtou(slash + 1, NULL, 0);
 			if ((errno || plen > dst->bitlen)
-			 && (get_addr_1(&netmask_pfx, slash + 1, family)))
-				err = -1;
-			else if (netmask_pfx.family == AF_INET) {
+			 && get_addr_1(&netmask_pfx, slash + 1, family) != 0
+			) {
+				goto bad;
+			}
+			if (netmask_pfx.family == AF_INET) {
 				/* fill in prefix length of dotted quad */
 				uint32_t mask = ntohl(netmask_pfx.data[0]);
 				uint32_t host = ~mask;
 
 				/* a valid netmask must be 2^n - 1 */
-				if (!(host & (host + 1))) {
-					for (plen = 0; mask; mask <<= 1)
-						++plen;
-					if (plen <= dst->bitlen) {
-						dst->bitlen = plen;
-						/* dst->flags |= PREFIXLEN_SPECIFIED; */
-					} else
-						err = -1;
-				} else
-					err = -1;
-			} else {
-				/* plain prefix */
-				dst->bitlen = plen;
+				if (host & (host + 1))
+					goto bad;
+
+				for (plen = 0; mask; mask <<= 1)
+					++plen;
+				if (plen > dst->bitlen)
+					goto bad;
+				/* dst->flags |= PREFIXLEN_SPECIFIED; */
 			}
+			dst->bitlen = plen;
 		}
 	}
+
 	if (slash)
 		*slash = '/';
-	return err;
+	return;
+ bad:
+	bb_error_msg_and_die("an %s %s is expected rather than \"%s\"", "inet", "prefix", arg);
 }
 
 int get_addr(inet_prefix *dst, char *arg, int family)
@@ -163,15 +188,12 @@ int get_addr(inet_prefix *dst, char *arg, int family)
 	return 0;
 }
 
-int get_prefix(inet_prefix *dst, char *arg, int family)
+void get_prefix(inet_prefix *dst, char *arg, int family)
 {
 	if (family == AF_PACKET) {
 		bb_error_msg_and_die("\"%s\" may be inet %s, but it is not allowed in this context", arg, "prefix");
 	}
-	if (get_prefix_1(dst, arg, family)) {
-		bb_error_msg_and_die("an %s %s is expected rather than \"%s\"", "inet", "prefix", arg);
-	}
-	return 0;
+	get_prefix_1(dst, arg, family);
 }
 
 uint32_t get_addr32(char *name)
@@ -204,10 +226,10 @@ void duparg2(const char *key, const char *arg)
 	bb_error_msg_and_die("either \"%s\" is duplicate, or \"%s\" is garbage", key, arg);
 }
 
-int inet_addr_match(inet_prefix *a, inet_prefix *b, int bits)
+int inet_addr_match(const inet_prefix *a, const inet_prefix *b, int bits)
 {
-	uint32_t *a1 = a->data;
-	uint32_t *a2 = b->data;
+	const uint32_t *a1 = a->data;
+	const uint32_t *a2 = b->data;
 	int words = bits >> 5;
 
 	bits &= 0x1f;
diff --git a/networking/libiproute/utils.h b/networking/libiproute/utils.h
index 93c9d25d6..5fb4a862c 100644
--- a/networking/libiproute/utils.h
+++ b/networking/libiproute/utils.h
@@ -58,9 +58,9 @@ struct ipx_addr {
 
 extern uint32_t get_addr32(char *name);
 extern int get_addr_1(inet_prefix *dst, char *arg, int family);
-/*extern int get_prefix_1(inet_prefix *dst, char *arg, int family);*/
+/*extern void get_prefix_1(inet_prefix *dst, char *arg, int family);*/
 extern int get_addr(inet_prefix *dst, char *arg, int family);
-extern int get_prefix(inet_prefix *dst, char *arg, int family);
+extern void get_prefix(inet_prefix *dst, char *arg, int family);
 
 extern unsigned get_unsigned(char *arg, const char *errmsg);
 extern uint32_t get_u32(char *arg, const char *errmsg);
@@ -77,7 +77,7 @@ extern const char *format_host(int af, int len, void *addr, char *buf, int bufle
 void invarg(const char *, const char *) NORETURN;
 void duparg(const char *, const char *) NORETURN;
 void duparg2(const char *, const char *) NORETURN;
-int inet_addr_match(inet_prefix *a, inet_prefix *b, int bits);
+int inet_addr_match(const inet_prefix *a, const inet_prefix *b, int bits);
 
 const char *dnet_ntop(int af, const void *addr, char *str, size_t len);
 int dnet_pton(int af, const char *src, void *addr);