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Verified Commit 6be91cea authored by Lukas Jelinek's avatar Lukas Jelinek :file_cabinet:
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parser: unsupport all protocols other than TCP and UDP

parent e132a6e4
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Pipeline #102708 passed with stages
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        in 35 seconds
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        Inline Side-by-side
        fwlogs/parser.c
        + 49
        − 22
        View file @ 6be91cea
        ...@@ -6,6 +6,9 @@ ...@@ -6,6 +6,9 @@
        #include "log.h" #include "log.h"
        enum parse_result {SUCCESS = 0, LENGTH, PROTOCOL};
        size_t max_packet_size() { size_t max_packet_size() {
        return \ return \
        MAX(sizeof(struct ip), sizeof(struct ip6_hdr)) + MAX(sizeof(struct ip), sizeof(struct ip6_hdr)) +
        ...@@ -16,7 +19,8 @@ size_t max_packet_size() { ...@@ -16,7 +19,8 @@ size_t max_packet_size() {
        __attribute__((nonnull)) __attribute__((nonnull))
        static bool handle_ipv4(const void *payload, size_t payload_size, struct packet_data *dt) { static enum parse_result handle_ipv4(const void *payload, size_t payload_size, struct packet_data *dt) {
        enum parse_result res = SUCCESS;
        const struct ip *p = (struct ip*)payload; const struct ip *p = (struct ip*)payload;
        inet_ntop(AF_INET, &p->ip_src, dt->source_ip, sizeof(dt->source_ip)); inet_ntop(AF_INET, &p->ip_src, dt->source_ip, sizeof(dt->source_ip));
        ...@@ -27,32 +31,40 @@ static bool handle_ipv4(const void *payload, size_t payload_size, struct packet_ ...@@ -27,32 +31,40 @@ static bool handle_ipv4(const void *payload, size_t payload_size, struct packet_
        const void *phdr = payload + (4 * p->ip_hl); const void *phdr = payload + (4 * p->ip_hl);
        switch (p->ip_p) { switch (p->ip_p) {
        case IPPROTO_UDP: { case IPPROTO_UDP: {
        if (payload_size < (sizeof(struct ip) + sizeof(struct udphdr))) if (payload_size < (sizeof(struct ip) + sizeof(struct udphdr))) {
        return false; res = LENGTH;
        break;
        }
        const struct udphdr *udp = (struct udphdr*)phdr; const struct udphdr *udp = (struct udphdr*)phdr;
        dt->source_port = ntohs(udp->source); dt->source_port = ntohs(udp->source);
        dt->dest_port = ntohs(udp->dest); dt->dest_port = ntohs(udp->dest);
        break; break;
        } }
        case IPPROTO_TCP: { case IPPROTO_TCP: {
        if (payload_size < (sizeof(struct ip) + sizeof(struct tcphdr))) if (payload_size < (sizeof(struct ip) + sizeof(struct tcphdr))) {
        return false; res = LENGTH;
        break;
        }
        const struct tcphdr *tcp = (struct tcphdr*)phdr; const struct tcphdr *tcp = (struct tcphdr*)phdr;
        dt->source_port = ntohs(tcp->source); dt->source_port = ntohs(tcp->source);
        dt->dest_port = ntohs(tcp->dest); dt->dest_port = ntohs(tcp->dest);
        break; break;
        } }
        default: default:
        dt->source_port = 0; res = PROTOCOL;
        dt->dest_port = 0;
        } }
        return true; return res;
        } }
        __attribute__((nonnull)) __attribute__((nonnull))
        static bool handle_ipv6(const void *payload, size_t payload_size, struct packet_data *dt) { static enum parse_result handle_ipv6(const void *payload, size_t payload_size, struct packet_data *dt) {
        if (payload_size < sizeof(struct ip6_hdr)) enum parse_result res = SUCCESS;
        return false;
        if (payload_size < sizeof(struct ip6_hdr)) {
        res = LENGTH;
        return res;
        }
        const struct ip6_hdr *p = (struct ip6_hdr*)payload; const struct ip6_hdr *p = (struct ip6_hdr*)payload;
        inet_ntop(AF_INET6, &p->ip6_src, dt->source_ip, sizeof(dt->source_ip)); inet_ntop(AF_INET6, &p->ip6_src, dt->source_ip, sizeof(dt->source_ip));
        ...@@ -68,26 +80,29 @@ static bool handle_ipv6(const void *payload, size_t payload_size, struct packet_ ...@@ -68,26 +80,29 @@ static bool handle_ipv6(const void *payload, size_t payload_size, struct packet_
        const void *phdr = payload + sizeof(struct ip6_hdr); const void *phdr = payload + sizeof(struct ip6_hdr);
        switch (p->ip6_nxt) { switch (p->ip6_nxt) {
        case IPPROTO_UDP: { case IPPROTO_UDP: {
        if (payload_size < (sizeof(struct ip6_hdr) + sizeof(struct udphdr))) if (payload_size < (sizeof(struct ip6_hdr) + sizeof(struct udphdr))) {
        return false; res = LENGTH;
        break;
        }
        const struct udphdr *udp = (struct udphdr*)phdr; const struct udphdr *udp = (struct udphdr*)phdr;
        dt->source_port = ntohs(udp->source); dt->source_port = ntohs(udp->source);
        dt->dest_port = ntohs(udp->dest); dt->dest_port = ntohs(udp->dest);
        break; break;
        } }
        case IPPROTO_TCP: { case IPPROTO_TCP: {
        if (payload_size < (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))) if (payload_size < (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))) {
        return false; res = LENGTH;
        break;
        }
        const struct tcphdr *tcp = (struct tcphdr*)phdr; const struct tcphdr *tcp = (struct tcphdr*)phdr;
        dt->source_port = ntohs(tcp->source); dt->source_port = ntohs(tcp->source);
        dt->dest_port = ntohs(tcp->dest); dt->dest_port = ntohs(tcp->dest);
        break; break;
        } }
        default: default:
        dt->source_port = 0; res = PROTOCOL;
        dt->dest_port = 0;
        } }
        return true; return res;
        } }
        ...@@ -98,12 +113,20 @@ bool parse_packet(const void *data, size_t data_size, struct packet_data *packet ...@@ -98,12 +113,20 @@ bool parse_packet(const void *data, size_t data_size, struct packet_data *packet
        struct ip *p_ip = (struct ip*)data; struct ip *p_ip = (struct ip*)data;
        switch (p_ip->ip_v) { switch (p_ip->ip_v) {
        case 4: case 4:
        if (!handle_ipv4(data, data_size, packet_data)) switch (handle_ipv4(data, data_size, packet_data)) {
        goto invalid_size; case LENGTH:
        goto invalid_size;
        case PROTOCOL:
        goto unsupported_protocol;
        }
        break; break;
        case 6: case 6:
        if (!handle_ipv6(data, data_size, packet_data)) switch (handle_ipv6(data, data_size, packet_data)) {
        goto invalid_size; case LENGTH:
        goto invalid_size;
        case PROTOCOL:
        goto unsupported_protocol;
        }
        break; break;
        default: default:
        debug("Received packet with unknown IP version: %d", p_ip->ip_v); debug("Received packet with unknown IP version: %d", p_ip->ip_v);
        ...@@ -119,4 +142,8 @@ bool parse_packet(const void *data, size_t data_size, struct packet_data *packet ...@@ -119,4 +142,8 @@ bool parse_packet(const void *data, size_t data_size, struct packet_data *packet
        invalid_size: invalid_size:
        debug("Received packet has smaller size than expected IP header. Ignoring"); debug("Received packet has smaller size than expected IP header. Ignoring");
        return false; return false;
        unsupported_protocol:
        debug("Unsupported network protocol detected (other than TCP and UDP). Ignoring");
        return false;
        } }
        tests/parse_ipv4.c
        + 0
        − 11
        View file @ 6be91cea
        ...@@ -67,17 +67,6 @@ static struct packets { ...@@ -67,17 +67,6 @@ static struct packets {
        .dest_port = 53, .dest_port = 53,
        } }
        }, },
        {
        .data = icmp_data,
        .len = icmp_len,
        .expected = (struct packet_data){
        .proto = "ICMP",
        .source_ip = "192.168.2.1",
        .dest_ip = "192.168.2.148",
        .source_port = 0,
        .dest_port = 0,
        }
        },
        }; };
        ......
        tests/parse_ipv6.c
        + 0
        − 11
        View file @ 6be91cea
        ...@@ -71,17 +71,6 @@ static struct packets { ...@@ -71,17 +71,6 @@ static struct packets {
        .dest_port = 53, .dest_port = 53,
        } }
        }, },
        {
        .data = icmp_data,
        .len = icmp_len,
        .expected = (struct packet_data){
        .proto = "ICMPV6",
        .source_ip = "2001:1ae9:a3:df80::1",
        .dest_ip = "2001:1ae9:a3:df80::60",
        .source_port = 0,
        .dest_port = 0,
        }
        },
        }; };
        ......
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