diff options
| author | phk <phk@FreeBSD.org> | 2002-09-27 18:57:47 +0000 |
|---|---|---|
| committer | phk <phk@FreeBSD.org> | 2002-09-27 18:57:47 +0000 |
| commit | d61cac74b0dc667b645880b386219cacfb3c53f6 (patch) | |
| tree | 2e0b7f0095d2053a63219572fbeafde682841ff6 /sys | |
| parent | 834ddd1bcc092e4a26f16724892636b249316d70 (diff) | |
| download | FreeBSD-src-d61cac74b0dc667b645880b386219cacfb3c53f6.zip FreeBSD-src-d61cac74b0dc667b645880b386219cacfb3c53f6.tar.gz | |
Add the "Monitor" interface flag.
Setting this flag on an ethernet interface blocks transmission of packets
and discards incoming packets after BPF processing.
This is useful if you want to monitor network trafic but not interact
with the network in question.
Sponsored by: http://www.babeltech.dk
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/net/if.h | 1 | ||||
| -rw-r--r-- | sys/net/if_ethersubr.c | 7 |
2 files changed, 8 insertions, 0 deletions
diff --git a/sys/net/if.h b/sys/net/if.h index a11dc39..a87dd47 100644 --- a/sys/net/if.h +++ b/sys/net/if.h @@ -141,6 +141,7 @@ struct if_data { #define IFF_MULTICAST 0x8000 /* supports multicast */ #define IFF_POLLING 0x10000 /* Interface is in polling mode. */ #define IFF_PPROMISC 0x20000 /* user-requested promisc mode */ +#define IFF_MONITOR 0x40000 /* user-requested monitor mode */ /* flags set internally only: */ #define IFF_CANTCHANGE \ diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c index d92f405..0983724 100644 --- a/sys/net/if_ethersubr.c +++ b/sys/net/if_ethersubr.c @@ -162,6 +162,8 @@ ether_output(ifp, m, dst, rt0) senderr(error); #endif + if (ifp->if_flags & IFF_MONITOR) + senderr(ENETDOWN); if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) senderr(ENETDOWN); rt = rt0; @@ -583,6 +585,11 @@ ether_input(struct ifnet *ifp, struct ether_header *eh, struct mbuf *m) bpf_mtap(ifp, (struct mbuf *)&mh); } + if (ifp->if_flags & IFF_MONITOR) { + m_freem(m); + return; + } + #ifdef MAC mac_create_mbuf_from_ifnet(ifp, m); #endif |
