1PCAP_INJECT(3PCAP)                                          PCAP_INJECT(3PCAP)
2
3
4

NAME

6       pcap_inject, pcap_sendpacket - transmit a packet
7

SYNOPSIS

9       #include <pcap/pcap.h>
10
11       int pcap_inject(pcap_t *p, const void *buf, size_t size);
12       int pcap_sendpacket(pcap_t *p, const u_char *buf, int size);
13

DESCRIPTION

15       pcap_inject()  sends  a  raw  packet through the network interface; buf
16       points to the data of the packet, including the link-layer header,  and
17       size is the number of bytes in the packet.
18
19       Note  that,  even  if  you successfully open the network interface, you
20       might not have permission to send packets on it, or it might  not  sup‐
21       port  sending  packets; as pcap_open_live(3PCAP) doesn't have a flag to
22       indicate whether to open for capturing, sending, or capturing and send‐
23       ing,  you  cannot request an open that supports sending and be notified
24       at open time whether sending will be possible.   Note  also  that  some
25       devices might not support sending packets.
26
27       Note  that,  on  some  platforms,  the  link-layer header of the packet
28       that's sent might not be the same  as  the  link-layer  header  of  the
29       packet  supplied to pcap_inject(), as the source link-layer address, if
30       the header contains such an address, might be changed to be the address
31       assigned  to the interface on which the packet it sent, if the platform
32       doesn't support sending completely raw  and  unchanged  packets.   Even
33       worse,  some drivers on some platforms might change the link-layer type
34       field to whatever value libpcap used when attaching to the device, even
35       on  platforms  that  do  nominally  support  sending completely raw and
36       unchanged packets.
37
38       pcap_sendpacket() is like pcap_inject(), but it returns 0  on  success,
39       rather  than  returning  the  number  of bytes written.  (pcap_inject()
40       comes from OpenBSD; pcap_sendpacket() comes from  WinPcap/Npcap.   Both
41       are provided for compatibility.)
42

RETURN VALUE

44       pcap_inject()  returns  the  number  of  bytes  written  on success and
45       PCAP_ERROR on failure.
46
47       pcap_sendpacket() returns 0 on success and PCAP_ERROR on failure.
48
49       If PCAP_ERROR is returned, pcap_geterr(3PCAP) or pcap_perror(3PCAP) may
50       be called with p as an argument to fetch or display the error text.
51

SEE ALSO

53       pcap(3PCAP)
54
55
56
57                                 25 July 2018               PCAP_INJECT(3PCAP)
Impressum