tcp - TCP helper functions

       Generated automatically by Doxygen for libnetfilter_queue from the source code.

libnetfilter_queue                                Version 1.0.5                                           tcp(3)

structtcphdr*nfq_tcp_get_hdr(structpkt_buff*pktb)
       nfq_tcp_get_hdr - get the TCP header

       Parameterspktb pointer to user-space network packet buffer

       Returns
           validated pointer to the TCP header or NULL if the TCP header was not set or if a minimal length
           check fails.

       Note
           You have to call nfq_ip_set_transport_header() or nfq_ip6_set_transport_header() first to set the TCP
           header.

       Definition at line 43 of file tcp.c.

   void*nfq_tcp_get_payload(structtcphdr*tcph,structpkt_buff*pktb)
       nfq_tcp_get_payload - get the TCP packet payload

       Parameterstcph pointer to the TCP header
           pktb pointer to user-space network packet buffer

       Returns
           Pointer to the TCP payload, or NULL if malformed TCP packet.

       Definition at line 62 of file tcp.c.

   unsignedintnfq_tcp_get_payload_len(structtcphdr*tcph,structpkt_buff*pktb)
       nfq_tcp_get_payload_len - get the tcp packet payload

       Parameterstcph pointer to the TCP header
           pktb pointer to user-space network packet buffer

       Returns
           Length of TCP payload (user data)

       Definition at line 84 of file tcp.c.

   intnfq_tcp_mangle_ipv4(structpkt_buff*pktb,unsignedintmatch_offset,unsignedintmatch_len,constchar*rep_buffer,unsignedintrep_len)
       nfq_tcp_mangle_ipv4 - mangle TCP/IPv4 packet buffer

       Parameterspktb pointer to network packet buffer
           match_offset offset to content that you want to mangle
           match_len length of the existing content you want to mangle
           rep_buffer pointer to data you want to use to replace current content
           rep_len length of data you want to use to replace current content

       Returns
           1 for success and 0 for failure. See pktb_mangle() for failure case

       Note
           This function updates the IPv4 length and recalculates the IPv4 & TCP checksums for you.

       Warning
           After changing the length of a TCP message, the application will need to mangle sequence numbers in
           both directions until another change puts them in sync again

       Definition at line 219 of file tcp.c.

   intnfq_tcp_mangle_ipv6(structpkt_buff*pktb,unsignedintmatch_offset,unsignedintmatch_len,constchar*rep_buffer,unsignedintrep_len)
       nfq_tcp_mangle_ipv6 - Mangle TCP/IPv6 packet buffer

       Parameterspktb Pointer to network packet buffer
           match_offset Offset from start of TCP data of content that you want to mangle
           match_len Length of the existing content you want to mangle
           rep_buffer Pointer to data you want to use to replace current content
           rep_len Length of data you want to use to replace current content

       Returns
           1 for success and 0 for failure. See pktb_mangle() for failure case

       Note
           This function updates the IPv6 length and recalculates the TCP checksum for you.

       Warning
           After changing the length of a TCP message, the application will need to mangle sequence numbers in
           both directions until another change puts them in sync again

       Definition at line 254 of file tcp.c.

   intnfq_tcp_snprintf(char*buf,size_tsize,conststructtcphdr*tcph)
       nfq_pkt_snprintf_tcp_hdr - print tcp header into one buffer in a humnan readable way

       Parametersbuf pointer to buffer that is used to print the object
           size size of the buffer (or remaining room in it).
           tcph pointer to a valid tcp header.

       Returns
           Same as snprintfSeealsosnprintf(3)

       Definition at line 160 of file tcp.c.

       tcp - TCP helper functions

ModulesInternalTCPfunctionsFunctions
       struct tcphdr * nfq_tcp_get_hdr (struct pkt_buff *pktb)
       void * nfq_tcp_get_payload (struct tcphdr *tcph, struct pkt_buff *pktb)
       unsigned int nfq_tcp_get_payload_len (struct tcphdr *tcph, struct pkt_buff *pktb)
       int nfq_tcp_snprintf (char *buf, size_t size, const struct tcphdr *tcph)
       int nfq_tcp_mangle_ipv4 (struct pkt_buff *pktb, unsigned int match_offset, unsigned int match_len, const
           char *rep_buffer, unsigned int rep_len)
       int nfq_tcp_mangle_ipv6 (struct pkt_buff *pktb, unsigned int match_offset, unsigned int match_len, const
           char *rep_buffer, unsigned int rep_len)