xnu-3789.70.16.tar.gz

[apple/xnu.git] / bsd / man / man4 / ip.4

diff --git a/bsd/man/man4/ip.4 b/bsd/man/man4/ip.4
index c351178e1c1f1ed867cd62a9fc76901c24da4549..c5cc79b90199f56c2311498fa7f63fd0f9fe084b 100644 (file)
--- a/bsd/man/man4/ip.4
+++ b/bsd/man/man4/ip.4
@@ -129,10 +129,29 @@ that contains a cmsghdr structure followed by the
 address. 
 The 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
+.Pp
+If the 
+.Dv IP_RECVTOS 
+option is enabled on a 
+.Dv SOCK_DGRAM 
+or 
+.Dv SOCK_RAW 
+socket,
+the
+.Xr recvmsg
+call will return the TOS (type of service) field of the IP header.
+The msg_control field in the msghdr structure points to a buffer 
+that contains a cmsghdr structure followed by the 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
 .Ss "Multicast Options"
 .Pp
 .Tn IP 
@@ -324,13 +343,14 @@ the fields of the IP header, including the following:
 ip->ip_v = IPVERSION;
 ip->ip_hl = hlen >> 2;
 ip->ip_id = 0;  /* 0 means kernel set appropriate value */
-ip->ip_off = htons(offset);
-ip->ip_len = htons(len);
+ip->ip_off = offset;
+ip->ip_len = len;
 .Ed
 .sp .5
-Additionally note that starting with
-.Tn OpenBSD 2.1
-the ip_off and ip_len fields are in network byte order.
+.Pp
+Note that 
+the ip_off and ip_len fields are in host byte order.
+.Pp
 If the header source address is set to 
 .Dv INADDR_ANY,
 the kernel will choose an appropriate address.
@@ -372,11 +392,11 @@ or longer than the option buffer provided.
 .El
 .Sh SEE ALSO
 .Xr getsockopt 2 ,
-.Xr send 2 ,
 .Xr recv 2 ,
-.Xr intro 4 ,
+.Xr send 2 ,
 .Xr icmp 4 ,
-.Xr inet 4
+.Xr inet 4 ,
+.Xr intro 4
 .Sh HISTORY
 The
 .Nm