plucky (3) pcap_sendpacket.3pcap.gz

NAME

       pcap_inject, pcap_sendpacket - transmit a packet

SYNOPSIS

       #include <pcap/pcap.h>

       int pcap_inject(pcap_t *p, const void *buf, size_t size);
       int pcap_sendpacket(pcap_t *p, const u_char *buf, int size);

DESCRIPTION

       pcap_inject()  sends  a  raw  packet through the network interface; buf points to the data of the packet,
       including the link-layer header, and size is the number of bytes in the packet.

       Note that, even if you successfully open the network interface, you might not  have  permission  to  send
       packets  on  it, or it might not support sending packets; as pcap_open_live(3PCAP) doesn't have a flag to
       indicate whether to open for capturing, sending, or capturing and sending, you  cannot  request  an  open
       that supports sending and be notified at open time whether sending will be possible.  Note also that some
       devices might not support sending packets.

       Note that, on some platforms, the link-layer header of the packet that's sent might not be  the  same  as
       the  link-layer  header of the packet supplied to pcap_inject(), as the source link-layer address, if the
       header contains such an address, might be changed to be the address assigned to the  interface  on  which
       the  packet  it sent, if the platform doesn't support sending completely raw and unchanged packets.  Even
       worse, some drivers on some platforms might change the link-layer type field to  whatever  value  libpcap
       used when attaching to the device, even on platforms that do nominally support sending completely raw and
       unchanged packets.

       pcap_sendpacket() is like pcap_inject(), but it returns 0 on success, rather than returning the number of
       bytes  written.  (pcap_inject() comes from OpenBSD; pcap_sendpacket() comes from WinPcap/Npcap.  Both are
       provided for compatibility.)

RETURN VALUE

       pcap_inject() returns the number of bytes written on success, PCAP_ERROR_NOT_ACTIVATED  if  called  on  a
       capture handle that has been created but not activated, and PCAP_ERROR on other errors.

       pcap_sendpacket()  returns  0 on success, PCAP_ERROR_NOT_ACTIVATED if called on a capture handle that has
       been created but not activated, and PCAP_ERROR on other errors.

       If PCAP_ERROR is returned, pcap_geterr(3PCAP) or pcap_perror(3PCAP) may be called with p as  an  argument
       to fetch or display the error text.

SEE ALSO

       pcap(3PCAP)

                                                  5 March 2022                                PCAP_INJECT(3PCAP)