diff options
Diffstat (limited to 'share/man/man4/ip.4')
| -rw-r--r-- | share/man/man4/ip.4 | 47 |
1 files changed, 37 insertions, 10 deletions
diff --git a/share/man/man4/ip.4 b/share/man/man4/ip.4 index cf16d65..d921c15f 100644 --- a/share/man/man4/ip.4 +++ b/share/man/man4/ip.4 @@ -32,7 +32,7 @@ .\" @(#)ip.4 8.2 (Berkeley) 11/30/93 .\" $FreeBSD$ .\" -.Dd November 14, 2011 +.Dd June 15, 2012 .Dt IP 4 .Os .Sh NAME @@ -165,7 +165,7 @@ The .Vt cmsghdr fields have the following values: .Bd -literal -cmsg_len = sizeof(struct in_addr) +cmsg_len = CMSG_LEN(sizeof(struct in_addr)) cmsg_level = IPPROTO_IP cmsg_type = IP_RECVDSTADDR .Ed @@ -184,7 +184,7 @@ structure followed by the address. The cmsghdr fields should have the following values: .Bd -literal -cmsg_len = sizeof(struct in_addr) +cmsg_len = CMSG_LEN(sizeof(struct in_addr)) cmsg_level = IPPROTO_IP cmsg_type = IP_SENDSRCADDR .Ed @@ -215,7 +215,8 @@ before transmission. This is in contrast to the default behavior of the system, which is to transmit undirected broadcasts via the first network interface with the -.Dv IFF_BROADCAST flag set. +.Dv IFF_BROADCAST +flag set. .Pp This option allows applications to choose which interface is used to transmit an undirected broadcast @@ -226,7 +227,7 @@ configured with the broadcast address 192.168.2.255: .Bd -literal char msg[512]; struct sockaddr_in sin; -u_char onesbcast = 1; /* 0 = disable (default), 1 = enable */ +int onesbcast = 1; /* 0 = disable (default), 1 = enable */ setsockopt(s, IPPROTO_IP, IP_ONESBCAST, &onesbcast, sizeof(onesbcast)); sin.sin_addr.s_addr = inet_addr("192.168.2.255"); @@ -235,12 +236,14 @@ sendto(s, msg, sizeof(msg), 0, &sin, sizeof(sin)); .Ed .Pp It is the application's responsibility to set the -.Dv IP_TTL option +.Dv IP_TTL +option to an appropriate value in order to prevent broadcast storms. The application must have sufficient credentials to set the .Dv SO_BROADCAST socket level option, otherwise the -.Dv IP_ONESBCAST option has no effect. +.Dv IP_ONESBCAST +option has no effect. .Pp If the .Dv IP_BINDANY @@ -276,13 +279,36 @@ that contains a cmsghdr structure followed by the .Tn TTL . The cmsghdr fields have the following values: .Bd -literal -cmsg_len = sizeof(u_char) +cmsg_len = CMSG_LEN(sizeof(u_char)) cmsg_level = IPPROTO_IP cmsg_type = IP_RECVTTL .Ed .\" .Pp If the +.Dv IP_RECVTOS +option is enabled on a +.Dv SOCK_DGRAM +socket, the +.Xr recvmsg 2 +call will return the +.Tn IP +.Tn TOS +(type of service) field for a +.Tn UDP +datagram. +The msg_control field in the msghdr structure points to a buffer +that contains a cmsghdr structure followed by the +.Tn TOS . +The cmsghdr fields have the following values: +.Bd -literal +cmsg_len = CMSG_LEN(sizeof(u_char)) +cmsg_level = IPPROTO_IP +cmsg_type = IP_RECVTOS +.Ed +.\" +.Pp +If the .Dv IP_RECVIF option is enabled on a .Dv SOCK_DGRAM @@ -304,7 +330,7 @@ The .Vt cmsghdr fields have the following values: .Bd -literal -cmsg_len = sizeof(struct sockaddr_dl) +cmsg_len = CMSG_LEN(sizeof(struct sockaddr_dl)) cmsg_level = IPPROTO_IP cmsg_type = IP_RECVIF .Ed @@ -851,4 +877,5 @@ Before packets received on raw IP sockets had the .Va ip_hl subtracted from the -.Va ip_len field. +.Va ip_len +field. |
