NAME

       udp - UDP helper functions

SYNOPSIS

   Modules
       Internal UDP functions

   Functions
       struct udphdr * nfq_udp_get_hdr (struct pkt_buff *pktb)
       void * nfq_udp_get_payload (struct udphdr *udph, struct pkt_buff *pktb)
       unsigned int nfq_udp_get_payload_len (struct udphdr *udph, struct pkt_buff *pktb)
       int nfq_udp_mangle_ipv4 (struct pkt_buff *pktb, unsigned int match_offset, unsigned int
           match_len, const char *rep_buffer, unsigned int rep_len)
       int nfq_udp_mangle_ipv6 (struct pkt_buff *pktb, unsigned int match_offset, unsigned int
           match_len, const char *rep_buffer, unsigned int rep_len)
       int nfq_udp_snprintf (char *buf, size_t size, const struct udphdr *udph)

Detailed Description

Function Documentation

   struct udphdr * nfq_udp_get_hdr (struct pkt_buff * pktb)
       nfq_udp_get_hdr - get the UDP header.

       Parameters
           pktb Pointer to userspace network packet buffer

       Returns
           validated pointer to the UDP header or NULL if the UDP 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 UDP header.

       Definition at line 43 of file udp.c.

   void * nfq_udp_get_payload (struct udphdr * udph, struct pkt_buff * pktb)
       nfq_udp_get_payload - get the UDP packet payload.

       Parameters
           udph Pointer to UDP header
           pktb Pointer to userspace network packet buffer

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

       Definition at line 62 of file udp.c.

   unsigned int nfq_udp_get_payload_len (struct udphdr * udph, struct pkt_buff * pktb)
       nfq_udp_get_payload_len - get the udp packet payload.

       Parameters
           udph Pointer to UDP header
           pktb Pointer to userspace network packet buffer

       Returns
           Length of UDP payload (user data)

       Definition at line 84 of file udp.c.

   int nfq_udp_mangle_ipv4 (struct pkt_buff * pktb, unsigned int match_offset, unsigned int
       match_len, const char * rep_buffer, unsigned int rep_len)
       nfq_udp_mangle_ipv4 - Mangle UDP/IPv4 packet buffer

       Parameters
           pktb Pointer to network packet buffer
           match_offset Offset from start of UDP 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 IPv4 and UDP lengths and recalculates their checksums for
           you.

       Definition at line 150 of file udp.c.

   int nfq_udp_mangle_ipv6 (struct pkt_buff * pktb, unsigned int match_offset, unsigned int
       match_len, const char * rep_buffer, unsigned int rep_len)
       nfq_udp_mangle_ipv6 - Mangle UDP/IPv6 packet buffer

       Parameters
           pktb Pointer to network packet buffer
           match_offset Offset from start of UDP 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 and UDP lengths and recalculates the UDP checksum for
           you.

       Definition at line 184 of file udp.c.

   int nfq_udp_snprintf (char * buf, size_t size, const struct udphdr * udph)
       nfq_pkt_snprintf_udp_hdr - print udp header into one buffer in a humnan readable way

       Parameters
           buf pointer to buffer that is used to print the object
           size size of the buffer (or remaining room in it).
           udph pointer to a valid udp header.

       Returns
           The number of characters notionally written (excluding trailing NUL)

       See also
           snprintf(3)

       Definition at line 220 of file udp.c.

Author

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