From: Aurelien DARRAGON <adarragon@haproxy.com>
Date: Tue, 5 Sep 2023 12:58:53 +0000 (+0200)
Subject: MINOR: pattern/ip: offload ip conversion logic to helper functions
X-Git-Tag: v2.9-dev6~15
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f80122db266700259daa448b92a763e1b7a26dab;p=thirdparty%2Fhaproxy.git

MINOR: pattern/ip: offload ip conversion logic to helper functions

Now that v4tov6() and v6tov4() were reworked to match behavior from
pat_match_ip() function in ("MINOR: tools/ip: v4tov6() and v6tov4()
rework"), we can remove code duplication in pat_match_ip() by directly
using those dedicated functions where relevant.
---

diff --git a/src/pattern.c b/src/pattern.c
index b393112d30..0a71237f3b 100644
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -966,7 +966,7 @@ struct pattern *pat_match_len(struct sample *smp, struct pattern_expr *expr, int
 
 struct pattern *pat_match_ip(struct sample *smp, struct pattern_expr *expr, int fill)
 {
-	unsigned int v4; /* in network byte order */
+	struct in_addr v4; /* in network byte order */
 	struct in6_addr tmp6;
 	struct in_addr *s;
 	struct ebmb_node *node;
@@ -1000,12 +1000,9 @@ struct pattern *pat_match_ip(struct sample *smp, struct pattern_expr *expr, int
 		}
 
 		/* The IPv4 sample don't match the IPv4 tree. Convert the IPv4
-		 * sample address to IPv6 with the mapping method using the ::ffff:
-		 * prefix, and try to lookup in the IPv6 tree.
+		 * sample address to IPv6 and try to lookup in the IPv6 tree.
 		 */
-		memset(&tmp6, 0, 10);
-		write_u16(&tmp6.s6_addr[10], htons(0xffff));
-		write_u32(&tmp6.s6_addr[12], smp->data.u.ipv4.s_addr);
+		v4tov6(&tmp6, &smp->data.u.ipv4);
 		node = ebmb_lookup_longest(&expr->pattern_tree_2, &tmp6);
 		while (node) {
 			elt = ebmb_entry(node, struct pattern_tree, node);
@@ -1048,22 +1045,8 @@ struct pattern *pat_match_ip(struct sample *smp, struct pattern_expr *expr, int
 			return &static_pattern;
 		}
 
-		/* Try to convert 6 to 4 when the start of the ipv6 address match the
-		 * following forms :
-		 *   - ::ffff:ip:v4 (ipv4 mapped)
-		 *   - ::0000:ip:v4 (old ipv4 mapped)
-		 *   - 2002:ip:v4:: (6to4)
-		 */
-		if ((read_u64(&smp->data.u.ipv6.s6_addr[0]) == 0 &&
-		     (read_u32(&smp->data.u.ipv6.s6_addr[8]) == 0 ||
-		      read_u32(&smp->data.u.ipv6.s6_addr[8]) == htonl(0xFFFF))) ||
-		    read_u16(&smp->data.u.ipv6.s6_addr[0]) == htons(0x2002)) {
-			if (read_u32(&smp->data.u.ipv6.s6_addr[0]) == 0)
-				v4 = read_u32(&smp->data.u.ipv6.s6_addr[12]);
-			else
-				v4 = htonl((ntohs(read_u16(&smp->data.u.ipv6.s6_addr[2])) << 16) +
-				           ntohs(read_u16(&smp->data.u.ipv6.s6_addr[4])));
-
+		/* Try to convert 6 to 4 */
+		if (v6tov4(&v4, &smp->data.u.ipv6)) {
 			/* Lookup an IPv4 address in the expression's pattern tree using the longest
 			 * match method.
 			 */
@@ -1097,25 +1080,11 @@ struct pattern *pat_match_ip(struct sample *smp, struct pattern_expr *expr, int
 
 		/* The input sample is IPv4, use it as is. */
 		if (smp->data.type == SMP_T_IPV4) {
-			v4 = smp->data.u.ipv4.s_addr;
+			v4.s_addr = smp->data.u.ipv4.s_addr;
 		}
 		else if (smp->data.type == SMP_T_IPV6) {
-			/* v4 match on a V6 sample. We want to check at least for
-			 * the following forms :
-			 *   - ::ffff:ip:v4 (ipv4 mapped)
-			 *   - ::0000:ip:v4 (old ipv4 mapped)
-			 *   - 2002:ip:v4:: (6to4)
-			 */
-			if (read_u64(&smp->data.u.ipv6.s6_addr[0]) == 0 &&
-			    (read_u32(&smp->data.u.ipv6.s6_addr[8]) == 0 ||
-			     read_u32(&smp->data.u.ipv6.s6_addr[8]) == htonl(0xFFFF))) {
-				v4 = read_u32(&smp->data.u.ipv6.s6_addr[12]);
-			}
-			else if (read_u16(&smp->data.u.ipv6.s6_addr[0]) == htons(0x2002)) {
-				v4 = htonl((ntohs(read_u16(&smp->data.u.ipv6.s6_addr[2])) << 16) +
-				           ntohs(read_u16(&smp->data.u.ipv6.s6_addr[4])));
-			}
-			else
+			/* v4 match on a V6 sample. Try to convert v6 form to v4 address */
+			if (!v6tov4(&v4, &smp->data.u.ipv6))
 				continue;
 		} else {
 		  /* impossible */
@@ -1123,7 +1092,7 @@ struct pattern *pat_match_ip(struct sample *smp, struct pattern_expr *expr, int
 		}
 
 		/* Check if the input sample match the current pattern. */
-		if (((v4 ^ pattern->val.ipv4.addr.s_addr) & pattern->val.ipv4.mask.s_addr) == 0)
+		if (((v4.s_addr ^ pattern->val.ipv4.addr.s_addr) & pattern->val.ipv4.mask.s_addr) == 0)
 			return pattern;
 	}
 	return NULL;