Fix overflow in test + add correct structures for encapsulation of

packets in ICMP

Author: danielinux

src/test/unit/unit_tests_dns_dhcp.c

@@ -2039,7 +2039,7 @@ START_TEST(test_icmp_input_dest_unreach_port_unreachable_closes_matching_tcp_soc
     struct wolfIP s;
     struct tsocket *ts;
     struct wolfIP_icmp_dest_unreachable_packet icmp;
-    struct wolfIP_tcp_seg *orig;
+    struct wolfIP_tcp_wire_prefix *orig;
     uint32_t frame_len;
 
     wolfIP_init(&s);
@@ -2065,15 +2065,14 @@ START_TEST(test_icmp_input_dest_unreach_port_unreachable_closes_matching_tcp_soc
     icmp.type = ICMP_DEST_UNREACH;
     icmp.code = ICMP_PORT_UNREACH;
 
-    orig = (struct wolfIP_tcp_seg *)icmp.orig_packet;
+    orig = (struct wolfIP_tcp_wire_prefix *)icmp.orig_packet;
     orig->ip.ver_ihl = 0x45;
     orig->ip.proto = WI_IPPROTO_TCP;
     orig->ip.src = ee32(ts->local_ip);
     orig->ip.dst = ee32(ts->remote_ip);
-    orig->ip.len = ee16(IP_HEADER_LEN + TCP_HEADER_LEN);
+    orig->ip.len = ee16(IP_HEADER_LEN + 8U);
     orig->src_port = ee16(ts->src_port);
     orig->dst_port = ee16(ts->dst_port);
-    orig->hlen = TCP_HEADER_LEN << 2;
 
     icmp.csum = ee16(icmp_checksum((struct wolfIP_icmp_packet *)&icmp,
                 ICMP_DEST_UNREACH_SIZE));
@@ -2090,7 +2089,7 @@ START_TEST(test_icmp_input_dest_unreach_frag_needed_reduces_tcp_peer_mss)
     struct wolfIP s;
     struct tsocket *ts;
     struct wolfIP_icmp_dest_unreachable_packet icmp;
-    struct wolfIP_tcp_seg *orig;
+    struct wolfIP_tcp_wire_prefix *orig;
     uint32_t frame_len;
     uint16_t next_hop_mtu;
 
@@ -2116,19 +2115,18 @@ START_TEST(test_icmp_input_dest_unreach_frag_needed_reduces_tcp_peer_mss)
     icmp.ip.proto = WI_IPPROTO_ICMP;
     icmp.ip.len = ee16(IP_HEADER_LEN + ICMP_DEST_UNREACH_SIZE);
     icmp.type = ICMP_DEST_UNREACH;
-    icmp.code = 4;
+    icmp.code = ICMP_FRAG_NEEDED;
     next_hop_mtu = ee16(576U);
     memcpy(&icmp.unused[2], &next_hop_mtu, sizeof(next_hop_mtu));
 
-    orig = (struct wolfIP_tcp_seg *)icmp.orig_packet;
+    orig = (struct wolfIP_tcp_wire_prefix *)icmp.orig_packet;
     orig->ip.ver_ihl = 0x45;
     orig->ip.proto = WI_IPPROTO_TCP;
     orig->ip.src = ee32(ts->local_ip);
     orig->ip.dst = ee32(ts->remote_ip);
-    orig->ip.len = ee16(IP_HEADER_LEN + TCP_HEADER_LEN);
+    orig->ip.len = ee16(IP_HEADER_LEN + 8U);
     orig->src_port = ee16(ts->src_port);
     orig->dst_port = ee16(ts->dst_port);
-    orig->hlen = TCP_HEADER_LEN << 2;
 
     icmp.csum = ee16(icmp_checksum((struct wolfIP_icmp_packet *)&icmp,
                 ICMP_DEST_UNREACH_SIZE));

src/wolfip.c

@@ -655,6 +655,16 @@ struct PACKED wolfIP_ip_packet {
     uint8_t data[0];
 };
 
+/* ICMP quotes the original IP packet without the link-layer header. */
+struct PACKED wolfIP_ip_wire {
+    uint8_t ver_ihl, tos;
+    uint16_t len, id, flags_fo;
+    uint8_t ttl, proto;
+    uint16_t csum;
+    ip4 src, dst;
+    uint8_t data[0];
+};
+
 /* Describe a TCP segment down to the datalink layer */
 struct PACKED wolfIP_tcp_seg {
     struct wolfIP_ip_packet ip;
@@ -665,6 +675,12 @@ struct PACKED wolfIP_tcp_seg {
     uint8_t data[0];
 };
 
+struct PACKED wolfIP_tcp_wire_prefix {
+    struct wolfIP_ip_wire ip;
+    uint16_t src_port, dst_port;
+    uint32_t seq;
+};
+
 struct PACKED tcp_opt_ts {
     /* Timestamp option (10 extra bytes) */
     uint8_t opt, len;
@@ -1967,8 +1983,8 @@ static void icmp_try_recv(struct wolfIP *s, unsigned int if_idx,
 static void icmp_try_deliver_tcp_error(struct wolfIP *s,
                                        const struct wolfIP_icmp_packet *icmp)
 {
-    const struct wolfIP_ip_packet *orig_ip;
-    const struct wolfIP_tcp_seg *orig_tcp;
+    const struct wolfIP_ip_wire *orig_ip;
+    const struct wolfIP_tcp_wire_prefix *orig_tcp;
     uint32_t icmp_len;
     uint32_t avail;
     uint32_t orig_hlen;
@@ -1986,7 +2002,7 @@ static void icmp_try_deliver_tcp_error(struct wolfIP *s,
     if (avail < IP_HEADER_LEN)
         return;
 
-    orig_ip = (const struct wolfIP_ip_packet *)((const uint8_t *)icmp +
+    orig_ip = (const struct wolfIP_ip_wire *)((const uint8_t *)icmp +
             sizeof(struct wolfIP_icmp_packet));
     orig_hlen = (uint32_t)((orig_ip->ver_ihl & 0x0FU) << 2);
     if (orig_hlen < IP_HEADER_LEN || orig_hlen > avail)
@@ -1996,7 +2012,7 @@ static void icmp_try_deliver_tcp_error(struct wolfIP *s,
     if (avail < (orig_hlen + 8U))
         return;
 
-    orig_tcp = (const struct wolfIP_tcp_seg *)orig_ip;
+    orig_tcp = (const struct wolfIP_tcp_wire_prefix *)orig_ip;
     for (i = 0; i < MAX_TCPSOCKETS; i++) {
         struct tsocket *t = &s->tcpsockets[i];