path: root/net/ipv4/ip_sockglue.c
diff options
authorEric Dumazet <edumazet@google.com>2016-09-07 21:52:56 -0700
committerDavid S. Miller <davem@davemloft.net>2016-09-08 17:45:57 -0700
commite895cdce683161081e3626c4f5a5c55cb72089f8 (patch)
tree59fb73c7597f6a72969991254145dc5ca1a4817d /net/ipv4/ip_sockglue.c
parentbpf: fix range propagation on direct packet access (diff)
ipv4: accept u8 in IP_TOS ancillary data
In commit f02db315b8d8 ("ipv4: IP_TOS and IP_TTL can be specified as ancillary data") Francesco added IP_TOS values specified as integer. However, kernel sends to userspace (at recvmsg() time) an IP_TOS value in a single byte, when IP_RECVTOS is set on the socket. It can be very useful to reflect all ancillary options as given by the kernel in a subsequent sendmsg(), instead of aborting the sendmsg() with EINVAL after Francesco patch. So this patch extends IP_TOS ancillary to accept an u8, so that an UDP server can simply reuse same ancillary block without having to mangle it. Jesper can then augment https://github.com/netoptimizer/network-testing/blob/master/src/udp_example02.c to add TOS reflection ;) Fixes: f02db315b8d8 ("ipv4: IP_TOS and IP_TTL can be specified as ancillary data") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Francesco Fusco <ffusco@redhat.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_sockglue.c')
1 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 71a52f4d4cff..af4919792b6a 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -284,9 +284,12 @@ int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc,
ipc->ttl = val;
case IP_TOS:
- if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
+ if (cmsg->cmsg_len == CMSG_LEN(sizeof(int)))
+ val = *(int *)CMSG_DATA(cmsg);
+ else if (cmsg->cmsg_len == CMSG_LEN(sizeof(u8)))
+ val = *(u8 *)CMSG_DATA(cmsg);
+ else
return -EINVAL;
- val = *(int *)CMSG_DATA(cmsg);
if (val < 0 || val > 255)
return -EINVAL;
ipc->tos = val;