From ee5e81f00051b5c373c8de16e3604fd6d3be699e Mon Sep 17 00:00:00 2001 From: Ilia K Date: Wed, 16 Sep 2009 05:53:07 +0000 Subject: [PATCH] add vif using local interface index instead of IP When routing daemon wants to enable forwarding of multicast traffic it performs something like: struct vifctl vc = { .vifc_vifi = 1, .vifc_flags = 0, .vifc_threshold = 1, .vifc_rate_limit = 0, .vifc_lcl_addr = ip, /* <--- ip address of physical interface, e.g. eth0 */ .vifc_rmt_addr.s_addr = htonl(INADDR_ANY), }; setsockopt(fd, IPPROTO_IP, MRT_ADD_VIF, &vc, sizeof(vc)); This leads (in the kernel) to calling vif_add() function call which search the (physical) device using assigned IP address: dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr); The current API (struct vifctl) does not allow to specify an interface other way than using it's IP, and if there are more than a single interface with specified IP only the first one will be found. The attached patch (against 2.6.30.4) allows to specify an interface by its index, instead of IP address: struct vifctl vc = { .vifc_vifi = 1, .vifc_flags = VIFF_USE_IFINDEX, /* NEW */ .vifc_threshold = 1, .vifc_rate_limit = 0, .vifc_lcl_ifindex = if_nametoindex("eth0"), /* NEW */ .vifc_rmt_addr.s_addr = htonl(INADDR_ANY), }; setsockopt(fd, IPPROTO_IP, MRT_ADD_VIF, &vc, sizeof(vc)); Signed-off-by: Ilia K. === modified file 'include/linux/mroute.h' Signed-off-by: David S. Miller --- include/linux/mroute.h | 13 +++++++++---- net/ipv4/ipmr.c | 12 +++++++++++- 2 files changed, 20 insertions(+), 5 deletions(-) diff --git a/include/linux/mroute.h b/include/linux/mroute.h index 08bc776d05e2..d5f69151f692 100644 --- a/include/linux/mroute.h +++ b/include/linux/mroute.h @@ -59,13 +59,18 @@ struct vifctl { unsigned char vifc_flags; /* VIFF_ flags */ unsigned char vifc_threshold; /* ttl limit */ unsigned int vifc_rate_limit; /* Rate limiter values (NI) */ - struct in_addr vifc_lcl_addr; /* Our address */ + union { + struct in_addr vifc_lcl_addr; /* Local interface address */ + int vifc_lcl_ifindex; /* Local interface index */ + }; struct in_addr vifc_rmt_addr; /* IPIP tunnel addr */ }; -#define VIFF_TUNNEL 0x1 /* IPIP tunnel */ -#define VIFF_SRCRT 0x2 /* NI */ -#define VIFF_REGISTER 0x4 /* register vif */ +#define VIFF_TUNNEL 0x1 /* IPIP tunnel */ +#define VIFF_SRCRT 0x2 /* NI */ +#define VIFF_REGISTER 0x4 /* register vif */ +#define VIFF_USE_IFINDEX 0x8 /* use vifc_lcl_ifindex instead of + vifc_lcl_addr to find an interface */ /* * Cache manipulation structures for mrouted and PIMd diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 630a56df7b47..c757f0b4b74c 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -469,8 +469,18 @@ static int vif_add(struct net *net, struct vifctl *vifc, int mrtsock) return err; } break; + + case VIFF_USE_IFINDEX: case 0: - dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr); + if (vifc->vifc_flags == VIFF_USE_IFINDEX) { + dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex); + if (dev && dev->ip_ptr == NULL) { + dev_put(dev); + return -EADDRNOTAVAIL; + } + } else + dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr); + if (!dev) return -EADDRNOTAVAIL; err = dev_set_allmulti(dev, 1); -- 2.20.1