diff options
Diffstat (limited to 'text2pcap.c')
| -rw-r--r-- | text2pcap.c | 70 |
1 files changed, 54 insertions, 16 deletions
diff --git a/text2pcap.c b/text2pcap.c index 7e696f3ca1..77310326ce 100644 --- a/text2pcap.c +++ b/text2pcap.c @@ -193,6 +193,10 @@ static guint32 hdr_src_port = 0; /* Dummy TCP header */ static int hdr_tcp = FALSE; +/* TCP sequence numbers when has_direction is true */ +static guint32 tcp_in_seq_num = 0; +static guint32 tcp_out_seq_num = 0; + /* Dummy SCTP header */ static int hdr_sctp = FALSE; static guint32 hdr_sctp_src = 0; @@ -319,6 +323,15 @@ static hdr_ip_t HDR_IP = {0x45, 0, 0, 0x3412, 0, 0, 0xff, 0, 0, #endif }; +/* Fixed IP address values */ +#ifdef WORDS_BIGENDIAN +#define IP_SRC 0x0a010101 +#define IP_DST 0x0a020202 +#else +#define IP_SRC 0x0101010a +#define IP_DST 0x0202020a +#endif + static struct { /* pseudo header for checksum calculation */ guint32 src_addr; guint32 dest_addr; @@ -656,6 +669,9 @@ write_current_packet (gboolean cont) if (curr_offset > header_length) { /* Write the packet */ + /* Is direction indication on with an inbound packet? */ + gboolean isInbound = has_direction && (direction == 2); + /* if defined IPv6 we should rewrite hdr_ethernet_proto anyways */ if (hdr_ipv6) { hdr_ethernet_proto = 0x86DD; @@ -680,8 +696,14 @@ write_current_packet (gboolean cont) /* Write IP header */ if (hdr_ip) { - if (hdr_ip_src_addr) HDR_IP.src_addr = hdr_ip_src_addr; - if (hdr_ip_dest_addr) HDR_IP.dest_addr = hdr_ip_dest_addr; + if (isInbound) { + HDR_IP.src_addr = hdr_ip_dest_addr ? hdr_ip_dest_addr : IP_DST; + HDR_IP.dest_addr = hdr_ip_src_addr? hdr_ip_src_addr : IP_SRC; + } + else { + HDR_IP.src_addr = hdr_ip_src_addr? hdr_ip_src_addr : IP_SRC; + HDR_IP.dest_addr = hdr_ip_dest_addr ? hdr_ip_dest_addr : IP_DST; + } HDR_IP.packet_length = g_htons(length - ip_offset + padding_length); HDR_IP.protocol = (guint8) hdr_ip_proto; @@ -689,10 +711,10 @@ write_current_packet (gboolean cont) HDR_IP.hdr_checksum = in_checksum(&HDR_IP, sizeof(HDR_IP)); write_bytes((const char *)&HDR_IP, sizeof(HDR_IP)); } else if (hdr_ipv6) { - if (memcmp(hdr_ipv6_src_addr, NO_IPv6_ADDRESS, sizeof(struct hdr_in6_addr))) - memcpy(&HDR_IPv6.ip6_src, &hdr_ipv6_src_addr, sizeof(struct hdr_in6_addr)); - if (memcmp(hdr_ipv6_dest_addr, NO_IPv6_ADDRESS, sizeof(struct hdr_in6_addr))) - memcpy(&HDR_IPv6.ip6_dst, &hdr_ipv6_dest_addr, sizeof(struct hdr_in6_addr)); + if (memcmp(isInbound ? hdr_ipv6_dest_addr : hdr_ipv6_src_addr, NO_IPv6_ADDRESS, sizeof(struct hdr_in6_addr))) + memcpy(&HDR_IPv6.ip6_src, isInbound ? &hdr_ipv6_dest_addr : &hdr_ipv6_src_addr, sizeof(struct hdr_in6_addr)); + if (memcmp(isInbound ? hdr_ipv6_src_addr : hdr_ipv6_dest_addr, NO_IPv6_ADDRESS, sizeof(struct hdr_in6_addr))) + memcpy(&HDR_IPv6.ip6_dst, isInbound ? &hdr_ipv6_src_addr : &hdr_ipv6_dest_addr, sizeof(struct hdr_in6_addr)); HDR_IPv6.ip6_ctlun.ip6_un2_vfc &= 0x0F; HDR_IPv6.ip6_ctlun.ip6_un2_vfc |= (6<< 4); @@ -725,8 +747,8 @@ write_current_packet (gboolean cont) guint32 u; /* initialize the UDP header */ - HDR_UDP.source_port = g_htons(hdr_src_port); - HDR_UDP.dest_port = g_htons(hdr_dest_port); + HDR_UDP.source_port = isInbound ? g_htons(hdr_dest_port): g_htons(hdr_src_port); + HDR_UDP.dest_port = isInbound ? g_htons(hdr_src_port) : g_htons(hdr_dest_port); HDR_UDP.length = pseudoh.length; HDR_UDP.checksum = 0; /* Note: g_ntohs()/g_htons() macro arg may be eval'd twice so calc value before invoking macro */ @@ -755,9 +777,19 @@ write_current_packet (gboolean cont) pseudoh.protocol = (guint8) hdr_ip_proto; pseudoh.length = g_htons(length - header_length + sizeof(HDR_TCP)); /* initialize the TCP header */ - HDR_TCP.source_port = g_htons(hdr_src_port); - HDR_TCP.dest_port = g_htons(hdr_dest_port); - /* HDR_TCP.seq_num already correct */ + HDR_TCP.source_port = isInbound ? g_htons(hdr_dest_port): g_htons(hdr_src_port); + HDR_TCP.dest_port = isInbound ? g_htons(hdr_src_port) : g_htons(hdr_dest_port); + /* set ack number if we have direction */ + if (has_direction) { + HDR_TCP.flags = 0x10; + HDR_TCP.ack_num = g_ntohl(isInbound ? tcp_out_seq_num : tcp_in_seq_num); + HDR_TCP.ack_num = g_htonl(HDR_TCP.ack_num); + } + else { + HDR_TCP.flags = 0; + HDR_TCP.ack_num = 0; + } + HDR_TCP.seq_num = isInbound ? tcp_in_seq_num : tcp_out_seq_num; HDR_TCP.window = g_htons(0x2000); HDR_TCP.checksum = 0; /* Note: g_ntohs()/g_htons() macro arg may be eval'd twice so calc value before invoking macro */ @@ -772,8 +804,14 @@ write_current_packet (gboolean cont) if (HDR_TCP.checksum == 0) /* differentiate between 'none' and 0 */ HDR_TCP.checksum = g_htons(1); write_bytes((const char *)&HDR_TCP, sizeof(HDR_TCP)); - HDR_TCP.seq_num = g_ntohl(HDR_TCP.seq_num) + length - header_length; - HDR_TCP.seq_num = g_htonl(HDR_TCP.seq_num); + if (isInbound) { + tcp_in_seq_num = g_ntohl(tcp_in_seq_num) + length - header_length; + tcp_in_seq_num = g_htonl(tcp_in_seq_num); + } + else { + tcp_out_seq_num = g_ntohl(tcp_out_seq_num) + length - header_length; + tcp_out_seq_num = g_htonl(tcp_out_seq_num); + } } /* Compute DATA chunk header */ @@ -802,8 +840,8 @@ write_current_packet (gboolean cont) if (hdr_sctp) { guint32 zero = 0; - HDR_SCTP.src_port = g_htons(hdr_sctp_src); - HDR_SCTP.dest_port = g_htons(hdr_sctp_dest); + HDR_SCTP.src_port = isInbound ? g_htons(hdr_sctp_dest): g_htons(hdr_sctp_src); + HDR_SCTP.dest_port = isInbound ? g_htons(hdr_sctp_src) : g_htons(hdr_sctp_dest); HDR_SCTP.tag = g_htonl(hdr_sctp_tag); HDR_SCTP.checksum = g_htonl(0); HDR_SCTP.checksum = crc32c((guint8 *)&HDR_SCTP, sizeof(HDR_SCTP), ~0); @@ -1451,7 +1489,7 @@ usage (gboolean is_error) " Example: -4 10.0.0.1,10.0.0.2\n" " -6 <srcip>,<destip> replace IPv6 header with specified\n" " dest and source address.\n" - " Example: -6 fe80:0:0:0:202:b3ff:fe1e:8329, 2001:0db8:85a3:0000:0000:8a2e:0370:7334\n" + " Example: -6 fe80:0:0:0:202:b3ff:fe1e:8329,2001:0db8:85a3:0000:0000:8a2e:0370:7334\n" " -u <srcp>,<destp> prepend dummy UDP header with specified\n" " source and destination ports (in DECIMAL).\n" " Automatically prepends Ethernet & IP headers as well.\n" |