net/act_pedit: Introduce 'add' operation

This command could be useful to inc/dec fields.

For example, to forward any TCP packet and decrease its TTL:
$ tc filter add dev enp0s9 protocol ip parent ffff: \
    flower ip_proto tcp \
    action pedit munge ip ttl add 0xff pipe \
    action mirred egress redirect dev veth0

In the example above, adding 0xff to this u8 field is actually
decreasing it by one, since the operation is masked.

Signed-off-by: Amir Vadai <amir@vadai.me>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 35 insertions, 4 deletions

diff --git a/include/net/tc_act/tc_pedit.h b/include/net/tc_act/tc_pedit.h

path: root/epoll2.h

#ifndef __EPOLL_H
#define __EPOLL_H

extern void set_epoll_descriptor(int fd_epoll, int action, int fd_toadd, int events);
extern int set_epoll_descriptor2(int fd_epoll, int action, int fd_toadd, int events);

#endif /* __EPOLL_H */