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
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
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.)
pcap_inject() returns the number of bytes written on success and
PCAP_ERROR on failure.
pcap_sendpacket() returns 0 on success and PCAP_ERROR on failure.
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.
This page is part of the libpcap (packet capture library)
project. Information about the project can be found at
⟨http://www.tcpdump.org/⟩. If you have a bug report for this
manual page, see ⟨http://www.tcpdump.org/#patches⟩. This page
was obtained from the project's upstream Git repository
⟨https://github.com/the-tcpdump-group/libpcap.git⟩ on 2021-08-27.
(At that time, the date of the most recent commit that was found
in the repository was 2021-08-17.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
25 July 2018 PCAP_INJECT(3PCAP)