diff options
Diffstat (limited to 'pingu_netlink.c')
| -rw-r--r-- | pingu_netlink.c | 117 |
1 files changed, 98 insertions, 19 deletions
diff --git a/pingu_netlink.c b/pingu_netlink.c index a032861..19ee4cd 100644 --- a/pingu_netlink.c +++ b/pingu_netlink.c @@ -186,8 +186,9 @@ static int netlink_enumerate(struct netlink_fd *fd, int family, int type) (struct sockaddr *) &addr, sizeof(addr)) >= 0; } -int netlink_route_replace_or_add(struct netlink_fd *fd, - in_addr_t destination, uint32_t masklen, in_addr_t gateway, int iface_index, int table) +int netlink_route_modify(struct netlink_fd *fd, int type, + in_addr_t destination, uint32_t masklen, in_addr_t gateway, + uint32_t metric, int iface_index, int table) { struct { struct nlmsghdr nlh; @@ -201,9 +202,11 @@ int netlink_route_replace_or_add(struct netlink_fd *fd, addr.nl_family = AF_NETLINK; req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)); - req.nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_REPLACE; - req.nlh.nlmsg_type = RTM_NEWROUTE; - + req.nlh.nlmsg_flags = NLM_F_REQUEST; + req.nlh.nlmsg_type = type; + if (type == RTM_NEWROUTE) + req.nlh.nlmsg_flags |= NLM_F_CREATE | NLM_F_REPLACE; + req.msg.rtm_family = AF_INET; req.msg.rtm_table = table; req.msg.rtm_dst_len = masklen; @@ -214,12 +217,30 @@ int netlink_route_replace_or_add(struct netlink_fd *fd, netlink_add_rtattr_l(&req.nlh, sizeof(req), RTA_DST, &destination, 4); netlink_add_rtattr_l(&req.nlh, sizeof(req), RTA_OIF, &iface_index, 4); netlink_add_rtattr_l(&req.nlh, sizeof(req), RTA_GATEWAY, &gateway, 4); + if (metric != 0) + netlink_add_rtattr_l(&req.nlh, sizeof(req), RTA_PRIORITY, &metric, 4); return sendto(fd->fd, (void *) &req, sizeof(req), 0, (struct sockaddr *) &addr, sizeof(addr)); } +int netlink_route_replace_or_add(struct netlink_fd *fd, + in_addr_t destination, uint32_t masklen, in_addr_t gateway, + uint32_t metric, int iface_index, int table) +{ + return netlink_route_modify(fd, RTM_NEWROUTE, destination, masklen, + gateway, metric, iface_index, table); +} + +int netlink_route_delete(struct netlink_fd *fd, + in_addr_t destination, uint32_t masklen, in_addr_t gateway, + uint32_t metric, int iface_index, int table) +{ + return netlink_route_modify(fd, RTM_DELROUTE, destination, masklen, + gateway, metric, iface_index, table); +} + int netlink_rule_modify(struct netlink_fd *fd, struct pingu_iface *iface, int type) { @@ -268,7 +289,7 @@ int netlink_rule_replace_or_add(struct netlink_fd *fd, struct pingu_iface *iface return netlink_rule_modify(fd, iface, RTM_NEWRULE); } -static void netlink_link_new(struct nlmsghdr *msg) +static void netlink_link_new_cb(struct nlmsghdr *msg) { struct pingu_iface *iface; struct ifinfomsg *ifi = NLMSG_DATA(msg); @@ -298,7 +319,7 @@ static void netlink_link_new(struct nlmsghdr *msg) netlink_rule_replace_or_add(&talk_fd, iface); } -static void netlink_link_del(struct nlmsghdr *msg) +static void netlink_link_del_cb(struct nlmsghdr *msg) { struct pingu_iface *iface; struct ifinfomsg *ifi = NLMSG_DATA(msg); @@ -320,7 +341,7 @@ static void netlink_link_del(struct nlmsghdr *msg) netlink_rule_del(&talk_fd, iface); } -static void netlink_addr_new(struct nlmsghdr *msg) +static void netlink_addr_new_cb(struct nlmsghdr *msg) { struct pingu_iface *iface; struct ifaddrmsg *ifa = NLMSG_DATA(msg); @@ -342,7 +363,7 @@ static void netlink_addr_new(struct nlmsghdr *msg) RTA_PAYLOAD(rta[IFA_LOCAL])); } -static void netlink_addr_del(struct nlmsghdr *nlmsg) +static void netlink_addr_del_cb(struct nlmsghdr *nlmsg) { struct pingu_iface *iface; struct ifaddrmsg *ifa = NLMSG_DATA(nlmsg); @@ -362,8 +383,7 @@ static void netlink_addr_del(struct nlmsghdr *nlmsg) pingu_iface_set_addr(iface, 0, NULL, 0); } - -static void netlink_route_new(struct nlmsghdr *msg) +static void netlink_route_new_cb(struct nlmsghdr *msg) { struct pingu_iface *iface; struct rtmsg *rtm = NLMSG_DATA(msg); @@ -371,8 +391,13 @@ static void netlink_route_new(struct nlmsghdr *msg) in_addr_t destination = 0; in_addr_t gateway = 0; + uint32_t metric = 0; char deststr[64], gwstr[64]; + /* ignore route changes that we made ourselves via talk_fd */ + if (msg->nlmsg_pid == getpid()) + return; + netlink_parse_rtattr(rta, RTA_MAX, RTM_RTA(rtm), RTM_PAYLOAD(msg)); if (rta[RTA_OIF] == NULL || rta[RTA_GATEWAY] == NULL || rtm->rtm_family != PF_INET || rtm->rtm_table != RT_TABLE_MAIN) @@ -381,6 +406,9 @@ static void netlink_route_new(struct nlmsghdr *msg) if (rta[RTA_DST] != NULL) destination = *(in_addr_t *)RTA_DATA(rta[RTA_DST]); + if (rta[RTA_PRIORITY] != NULL) + metric = *(uint32_t *)RTA_DATA(rta[RTA_PRIORITY]); + iface = pingu_iface_get_by_index(*(int*)RTA_DATA(rta[RTA_OIF])); if (iface == NULL) return; @@ -394,16 +422,58 @@ static void netlink_route_new(struct nlmsghdr *msg) iface->name, iface->route_table); netlink_route_replace_or_add(&talk_fd, destination, rtm->rtm_dst_len, - gateway, iface->index, iface->route_table); + gateway, metric, iface->index, iface->route_table); +} + +static void netlink_route_del_cb(struct nlmsghdr *msg) +{ + struct pingu_iface *iface; + struct rtmsg *rtm = NLMSG_DATA(msg); + struct rtattr *rta[RTA_MAX+1]; + + in_addr_t destination = 0; + in_addr_t gateway = 0; + uint32_t metric = 0; + char deststr[64], gwstr[64]; + + /* ignore route changes that we made ourselves via talk_fd */ + if (msg->nlmsg_pid == getpid()) + return; + + netlink_parse_rtattr(rta, RTA_MAX, RTM_RTA(rtm), RTM_PAYLOAD(msg)); + if (rta[RTA_OIF] == NULL || rta[RTA_GATEWAY] == NULL + || rtm->rtm_family != PF_INET || rtm->rtm_table != RT_TABLE_MAIN) + return; + + if (rta[RTA_DST] != NULL) + destination = *(in_addr_t *)RTA_DATA(rta[RTA_DST]); + + if (rta[RTA_PRIORITY] != NULL) + metric = *(uint32_t *)RTA_DATA(rta[RTA_PRIORITY]); + + iface = pingu_iface_get_by_index(*(int*)RTA_DATA(rta[RTA_OIF])); + if (iface == NULL) + return; + + gateway = *(in_addr_t *)RTA_DATA(rta[RTA_GATEWAY]); + + inet_ntop(rtm->rtm_family, &destination, deststr, sizeof(deststr)); + inet_ntop(rtm->rtm_family, &gateway, gwstr, sizeof(gwstr)); + + log_debug("Delete route to %s via %s dev %s table %i", deststr, gwstr, + iface->name, iface->route_table); + + netlink_route_delete(&talk_fd, destination, rtm->rtm_dst_len, + gateway, metric, iface->index, iface->route_table); } static const netlink_dispatch_f route_dispatch[RTM_MAX] = { - [RTM_NEWLINK] = netlink_link_new, - [RTM_DELLINK] = netlink_link_del, - [RTM_NEWADDR] = netlink_addr_new, - [RTM_DELADDR] = netlink_addr_del, - [RTM_NEWROUTE] = netlink_route_new, -// [RTM_DELROUTE] = netlink_route_del, + [RTM_NEWLINK] = netlink_link_new_cb, + [RTM_DELLINK] = netlink_link_del_cb, + [RTM_NEWADDR] = netlink_addr_new_cb, + [RTM_DELADDR] = netlink_addr_del_cb, + [RTM_NEWROUTE] = netlink_route_new_cb, + [RTM_DELROUTE] = netlink_route_del_cb, }; static void netlink_read_cb(struct ev_loop *loop, struct ev_io *w, int revents) @@ -484,7 +554,16 @@ int kernel_init(struct ev_loop *loop) netlink_enumerate(&talk_fd, PF_UNSPEC, RTM_GETADDR); netlink_read_cb(loop, &talk_fd.io, EV_READ); - netlink_enumerate(&talk_fd, PF_UNSPEC, RTM_GETROUTE); + /* man page netlink(7) says that first created netlink socket will + * get the getpid() assigned as nlmsg_pid. This is our talk_fd. + * + * Our route callbacks will ignore route changes made by ourselves + * (nlmsg_pid == getpid()) but we still need to get the initial + * route enumration. Therefore we use another netlink socket to + * "pretend" that it was not us who created those routes and the + * route callback will pick them up. + */ + netlink_enumerate(&netlink_fds[1], PF_UNSPEC, RTM_GETROUTE); netlink_read_cb(loop, &talk_fd.io, EV_READ); return TRUE; |