mirror/freebsd
1
0
Fork 0
mirror of https://git.FreeBSD.org/src.git synced 2025-02-08 19:12:49 +00:00
Code Issues Releases Activity

Document the IP_RECVIF socket option.

Browse Source 
Submitted by:	 Bruce M Simpson
This commit is contained in:
Matthew N. Dodd 2003-04-29 08:37:52 +00:00
parent 4161ee3d26
commit 3b5f87e60d
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=114204
1 changed files with 16 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
share/man/man4/ip.4
View File

@ -164,6 +164,22 @@ control message from
can be used directly as a control message for
.Xr sendmsg 2 .
.Pp
If the
.Dv IP_RECVIF
option is enabled on a
.Dv SOCK_DGRAM
socket, the
.Xr recvmsg 2
call returns a struct sockaddr_dl corresponding to the interface on which the
packet was received. The msg_control field in the msghdr structure points
to a buffer that contains a cmsghdr structure followed by the
struct sockaddr_dl. The cmsghdr fields have the following values:
.Bd -literal
cmsg_len = sizeof(struct sockaddr_dl)
cmsg_level = IPPROTO_IP
cmsg_type = IP_RECVIF
.Ed
.Pp
.Dv IP_PORTRANGE
may be used to set the port range used for selecting a local port number
on a socket with an unspecified (zero) port number.