Add support for parsing IP Authentication Header

6 files changed, 99 insertions, 47 deletions

diff --git a/include/stellar/packet.h b/include/stellar/packet.h
index d8d94c7..b867b6f 100644
--- a/include/stellar/packet.h
+++ b/include/stellar/packet.h
@@ -27,22 +27,23 @@ enum layer_type
     // L3 -- network layer
     LAYER_TYPE_IPV4 = 1 << 8,
     LAYER_TYPE_IPV6 = 1 << 9,
-    LAYER_TYPE_L3 = (LAYER_TYPE_IPV4 | LAYER_TYPE_IPV6),
+    LAYER_TYPE_IPAH = 1 << 10,
+    LAYER_TYPE_L3 = (LAYER_TYPE_IPV4 | LAYER_TYPE_IPV6 | LAYER_TYPE_IPAH),
 
     // L3 -- tunnel
-    LAYER_TYPE_GRE = 1 << 10,
+    LAYER_TYPE_GRE = 1 << 11,
     LAYER_TYPE_L3_TUN = (LAYER_TYPE_GRE),
 
     // L4 -- transport layer
-    LAYER_TYPE_UDP = 1 << 11,
-    LAYER_TYPE_TCP = 1 << 12,
-    LAYER_TYPE_ICMP = 1 << 13,
-    LAYER_TYPE_ICMP6 = 1 << 14,
+    LAYER_TYPE_UDP = 1 << 12,
+    LAYER_TYPE_TCP = 1 << 13,
+    LAYER_TYPE_ICMP = 1 << 14,
+    LAYER_TYPE_ICMP6 = 1 << 15,
     LAYER_TYPE_L4 = (LAYER_TYPE_UDP | LAYER_TYPE_TCP | LAYER_TYPE_ICMP | LAYER_TYPE_ICMP6),
 
     // L4 -- tunnel
-    LAYER_TYPE_VXLAN = 1 << 15,
-    LAYER_TYPE_GTPV1_U = 1 << 16,
+    LAYER_TYPE_VXLAN = 1 << 16,
+    LAYER_TYPE_GTPV1_U = 1 << 17,
 
     // ALL
     LAYER_TYPE_ALL = (LAYER_TYPE_L2 | LAYER_TYPE_L2_TUN | LAYER_TYPE_L3 | LAYER_TYPE_L3_TUN | LAYER_TYPE_L4 | LAYER_TYPE_VXLAN | LAYER_TYPE_GTPV1_U),
diff --git a/src/packet/ipv4_utils.h b/src/packet/ipv4_utils.h
index a67e7bf..f2dc3a0 100644
--- a/src/packet/ipv4_utils.h
+++ b/src/packet/ipv4_utils.h
@@ -40,6 +40,7 @@ static inline uint8_t ipv4_hdr_get_version(const struct ip *hdr)
     return hdr->ip_v;
 }
 
+// IP Options are included in the hdr_len field
 static inline uint8_t ipv4_hdr_get_hdr_len(const struct ip *hdr)
 {
     return hdr->ip_hl << 2;
diff --git a/src/packet/packet.cpp b/src/packet/packet.cpp
index 029258a..19c4a51 100644
--- a/src/packet/packet.cpp
+++ b/src/packet/packet.cpp
@@ -72,6 +72,7 @@ static inline const char *parse_mpls(struct packet *pkt, const char *data, uint1
 // 网络层
 static inline const char *parse_ipv4(struct packet *pkt, const char *data, uint16_t len);
 static inline const char *parse_ipv6(struct packet *pkt, const char *data, uint16_t len);
+static inline const char *parse_auth(struct packet *pkt, const char *data, uint16_t len);
 // 网络层 -- 隧道
 static inline const char *parse_gre(struct packet *pkt, const char *data, uint16_t len);
 // 传输层
@@ -133,6 +134,8 @@ static inline const char *layer_type_to_str(enum layer_type type)
         return "IPV4";
     case LAYER_TYPE_IPV6:
         return "IPV6";
+    case LAYER_TYPE_IPAH:
+        return "IPAH";
     case LAYER_TYPE_GRE:
         return "GRE";
     case LAYER_TYPE_UDP:
@@ -958,7 +961,21 @@ static inline const char *parse_ipv6(struct packet *pkt, const char *data, uint1
             return data;
         }
         struct ip6_ext *ext = (struct ip6_ext *)next_hdr_ptr;
-        uint16_t skip_len = ext->ip6e_len * 8 + 8;
+        uint16_t skip_len = 0;
+        if (next_proto == IPPROTO_AH)
+        {
+            /*
+             * https://datatracker.ietf.org/doc/html/rfc4302#section-2
+             * For IPv6, the total length of the header must be a multiple of 8-octet units.
+             * (Note that although IPv6 [DH98] characterizes AH as an extension header,
+             * its length is measured in 32-bit words, not the 64-bit words used by other IPv6 extension headers.)
+             */
+            skip_len = ext->ip6e_len * 4 + 8;
+        }
+        else
+        {
+            skip_len = ext->ip6e_len * 8 + 8;
+        }
         if (unlikely(skip_len > pld_len))
         {
             PACKET_LOG_DATA_INSUFFICIENCY(pkt, LAYER_TYPE_IPV6);
@@ -982,6 +999,59 @@ static inline const char *parse_ipv6(struct packet *pkt, const char *data, uint1
     return parse_l4(pkt, next_proto, layer->pld_ptr, layer->pld_len);
 }
 
+static inline const char *parse_auth(struct packet *pkt, const char *data, uint16_t len)
+{
+    /*
+     * https://datatracker.ietf.org/doc/html/rfc4302#section-2
+     * For IPv4: AH not IPv4 option, as an single layer
+     * For IPv6: AH as IPv6 extension header
+     *
+     * AH Format
+     *
+     *  0                   1                   2                   3
+     *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+     * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     * | Next Header   |  Payload Len  |          RESERVED             |
+     * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     * |                 Security Parameters Index (SPI)               |
+     * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     * |                    Sequence Number Field                      |
+     * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     * |                                                               |
+     * +                Integrity Check Value-ICV (variable)           |
+     * |                                                               |
+     * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     */
+
+    if (unlikely(len < 12))
+    {
+        PACKET_LOG_DATA_INSUFFICIENCY(pkt, LAYER_TYPE_IPAH);
+        return data;
+    }
+    /*
+     * https://datatracker.ietf.org/doc/html/rfc4302#section-2
+     * For IPv4, This 8-bit field specifies the length of AH in 32-bit words (4-byte units), minus "2".
+     * Thus, for example, if an integrity algorithm yields a 96-bit authentication value,
+     * this length field will be "4" (3 32-bit word fixed fields plus 3 32-bit words for the ICV, minus 2).
+     */
+    uint8_t next_proto = ((const uint8_t *)data)[0];
+    uint16_t hdr_len = ((const uint8_t *)data)[1] * 4 + 8;
+    if (unlikely(len < hdr_len))
+    {
+        PACKET_LOG_DATA_INSUFFICIENCY(pkt, LAYER_TYPE_IPAH);
+        return data;
+    }
+
+    struct packet_layer *layer = get_free_layer(pkt);
+    if (unlikely(layer == NULL))
+    {
+        return data;
+    }
+    SET_LAYER(pkt, layer, LAYER_TYPE_IPAH, hdr_len, data, len, 0);
+
+    return parse_l4(pkt, next_proto, layer->pld_ptr, layer->pld_len);
+}
+
 static inline const char *parse_gre(struct packet *pkt, const char *data, uint16_t len)
 {
 #define GRE_PRO_IPV4 (0x0800)
@@ -1042,10 +1112,19 @@ static inline const char *parse_udp(struct packet *pkt, const char *data, uint16
 
     if (udp_hdr_get_dst_port(hdr) == 2152 || udp_hdr_get_src_port(hdr) == 2152)
     {
+        // TODO
+        // check V1 or V2
+
         // GTP1U_PORT 2152
         return parse_gtpv1_u(pkt, layer->pld_ptr, layer->pld_len);
     }
 
+    if (udp_hdr_get_dst_port(hdr) == 2123 || udp_hdr_get_src_port(hdr) == 2123)
+    {
+        // TODO
+        // GTP-C - GTP control 2123
+    }
+
     if (udp_hdr_get_dst_port(hdr) == 1701)
     {
         // L2TP_DPORT 1701
@@ -1209,6 +1288,8 @@ static inline const char *parse_l4(struct packet *pkt, uint8_t next_proto, const
 {
     switch (next_proto)
     {
+    case IPPROTO_AH:
+        return parse_auth(pkt, data, len);
     case IPPROTO_TCP:
         return parse_tcp(pkt, data, len);
     case IPPROTO_UDP:
@@ -1294,6 +1375,8 @@ void packet_print_str(const struct packet *pkt)
         case LAYER_TYPE_IPV6:
             used = ipv6_hdr_to_str((const struct ip6_hdr *)layer->hdr_ptr, buffer, sizeof(buffer));
             break;
+        case LAYER_TYPE_IPAH:
+            break;
         case LAYER_TYPE_GRE:
             break;
         case LAYER_TYPE_UDP:
@@ -1320,38 +1403,6 @@ void packet_print_str(const struct packet *pkt)
     }
 }
 
-void packet_print_table(const struct packet *pkt)
-{
-    if (pkt == NULL)
-    {
-        return;
-    }
-
-    printf("packet: %p, data_ptr: %p, data_len: %u, trim_len: %u, layers_used: %u, layers_size: %u\n",
-           pkt, pkt->data_ptr, pkt->data_len, pkt->trim_len,
-           pkt->layers_used, pkt->layers_size);
-    printf("+------------+------------+------------+------------+------------+------------+------------+\n");
-    printf("| %-10s | %-10s | %-10s | %-10s | %-10s | %-10s | %-10s |\n",
-           "index", "type", "hdr ptr", "hdr offset", "hdr len", "pld ptr", "pld len");
-    printf("+------------+------------+------------+------------+------------+------------+------------+\n");
-
-    for (uint8_t i = 0; i < pkt->layers_used; i++)
-    {
-        const struct packet_layer *layer = &pkt->layers[i];
-        printf("| %-10u | %-10s | %-10p | %-10u | %-10u | %-10p | %-10u |\n",
-               i, layer_type_to_str(layer->type),
-               layer->hdr_ptr, layer->hdr_offset, layer->hdr_len,
-               layer->pld_ptr, layer->pld_len);
-        printf("+------------+------------+------------+------------+------------+------------+------------+\n");
-    }
-    printf("data: ");
-    for (uint16_t i = 0; i < pkt->data_len; i++)
-    {
-        printf("0x%02x, ", (uint8_t)pkt->data_ptr[i]);
-    }
-    printf("\n");
-}
-
 // return  0 : found
 // return -1 : not found
 int packet_get_innermost_tuple2(const struct packet *pkt, struct tuple2 *tuple)
diff --git a/src/packet/packet_priv.h b/src/packet/packet_priv.h
index ec60196..a40b049 100644
--- a/src/packet/packet_priv.h
+++ b/src/packet/packet_priv.h
@@ -55,7 +55,6 @@ struct packet
 // return innermost payload
 const char *packet_parse(struct packet *pkt, const char *data, uint16_t len);
 void packet_print_str(const struct packet *pkt);
-void packet_print_table(const struct packet *pkt);
 
 // direction 1: E2I
 // direction 0: I2E
diff --git a/test/packet_parser/cmp_layers.sh b/test/packet_parser/cmp_layers.sh
index 7d690f7..496961f 100644
--- a/test/packet_parser/cmp_layers.sh
+++ b/test/packet_parser/cmp_layers.sh
@@ -108,13 +108,10 @@ function preprocess_tshark_ouput() {
         ":data" ""
         ":sctp:m3ua" ""
         ":sctp" ""
-        ":teredo:ipv6:udp" ""
-        ":teredo:ipv6:tcp" ""
-        ":teredo:ipv6:icmpv6" ""
-        ":teredo:ipv6:gre:ip:udp" ""
         ":igmp" ""
         ":icmp:ip:tcp" ":icmp"
         ":pwethheuristic:pwethnocw" ""
+        ":ospf" ""
     )
     for ((i = 0; i < ${#kv_array[@]}; i += 2)); do
         key=${kv_array[i]}
diff --git a/test/packet_parser/packet_parser.cpp b/test/packet_parser/packet_parser.cpp
index ae6b68c..22f11bc 100644
--- a/test/packet_parser/packet_parser.cpp
+++ b/test/packet_parser/packet_parser.cpp
@@ -25,7 +25,7 @@ static int ipv6_proto_to_str(const struct packet_layer *ipv6_layer, char *buff,
         used += snprintf(buff + used, size - used, ":ipv6.routing");
         break;
     case IPPROTO_AH:
-        used += snprintf(buff + used, size - used, ":ipv6.ah");
+        used += snprintf(buff + used, size - used, ":ah");
         break;
     case IPPROTO_DSTOPTS:
         used += snprintf(buff + used, size - used, ":ipv6.dstopts");
@@ -79,6 +79,9 @@ static int packet_proto_to_str(const struct packet *pkt, char *buff, int size)
         case LAYER_TYPE_IPV6:
             used += ipv6_proto_to_str(layer, buff + used, size - used);
             break;
+        case LAYER_TYPE_IPAH:
+            used += snprintf(buff + used, size - used, "ah");
+            break;
         case LAYER_TYPE_GRE:
             used += snprintf(buff + used, size - used, "gre");
             break;