diff options
Diffstat (limited to 'common/src/decode_ipv4.c')
| -rw-r--r-- | common/src/decode_ipv4.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/common/src/decode_ipv4.c b/common/src/decode_ipv4.c new file mode 100644 index 0000000..8b98975 --- /dev/null +++ b/common/src/decode_ipv4.c @@ -0,0 +1,68 @@ +#include "decode_ipv4.h" + +#define IPV4_GET_HLEN(ip4_hdr) (((ip4_hdr)->ip_verhl & 0x0f) << 2) +#define IPV4_GET_IPPROTO(ip4_hdr) ((ip4_hdr)->ip_proto) +#define IPV4_GET_IPLEN(ip4_hdr) ((uint16_t)ntohs((ip4_hdr)->ip_len)) +#define IPV4_GET_SRC_ADDR(ip4_hdr) ((ip4_hdr)->ip4_hdrun1.ip4_un1.ip_src) +#define IPV4_GET_DST_ADDR(ip4_hdr) ((ip4_hdr)->ip4_hdrun1.ip4_un1.ip_dst) + +int decode_ipv4(ipv4_info_t *packet, const uint8_t *data, uint32_t len) +{ + // 检查包长是否大于 IPv4 header + if (len < IPV4_HEADER_LEN) + { + LOG_ERROR("Parser IPv4 Header: packet length too small %d", len); + return -1; + } + + // 检查 IPv4 header version + if (IP_GET_RAW_VER(data) != 4) + { + LOG_ERROR("Parser IPv4 Header: invalid IP version %d", IP_GET_RAW_VER(data)); + return -1; + } + + packet->hdr = (ipv4_header_t *)data; + // 检查 IPv4 header length + if (IPV4_GET_HLEN(packet->hdr) < IPV4_HEADER_LEN) + { + LOG_ERROR("Parser IPv4 Header: invalid IP header length %d", IPV4_GET_HLEN(packet->hdr)); + return -1; + } + + // 检查 IPv4 header total length + if (IPV4_GET_IPLEN(packet->hdr) < IPV4_GET_HLEN(packet->hdr)) + { + LOG_ERROR("Parser IPv4 Header: invalid IP header total length %d", IPV4_GET_IPLEN(packet->hdr)); + return -1; + } + + // 检查是否 IP 分片 + if (len < IPV4_GET_IPLEN(packet->hdr)) + { + LOG_ERROR("Parser IPv4 Header: trunc packet"); + return -1; + } + + inet_ntop(AF_INET, &IPV4_GET_SRC_ADDR(packet->hdr), packet->src_addr, sizeof(packet->src_addr)); + inet_ntop(AF_INET, &IPV4_GET_DST_ADDR(packet->hdr), packet->dst_addr, sizeof(packet->dst_addr)); + + packet->next_protocol = IPV4_GET_IPPROTO(packet->hdr); + packet->hdr_len = IPV4_GET_HLEN(packet->hdr); + packet->opts_len = packet->hdr_len - IPV4_HEADER_LEN; + packet->payload_len = len - packet->hdr_len; + packet->payload = (uint8_t *)data + packet->hdr_len; + + return 0; +} + +void dump_ipv4_info(uint32_t pkt_id, ipv4_info_t *packet) +{ + LOG_DEBUG("id: %u, ipv4_info: {src_addr: %s, dst_addr: %s, hdr_len: %u, opt_len: %u, data_len: %u}", + pkt_id, + packet->src_addr, + packet->dst_addr, + packet->hdr_len, + packet->opts_len, + packet->payload_len); +}
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