diff options
Diffstat (limited to 'netlink.c')
| -rw-r--r-- | netlink.c | 237 |
1 files changed, 148 insertions, 89 deletions
@@ -185,15 +185,71 @@ unsigned int nl_get_ext_if(sa_family_t af) } /** - * nl_route() - Get/set/copy routes for given interface and address family - * @op: Requested operation - * @ifi: Interface index in outer network namespace - * @ifi_ns: Interface index in target namespace for NL_SET, NL_DUP + * nl_route_get_def() - Get default route for given interface and address family + * @ifi: Interface index + * @af: Address family + * @gw: Default gateway to fill on NL_GET + */ +void nl_route_get_def(unsigned int ifi, sa_family_t af, void *gw) +{ + struct req_t { + struct nlmsghdr nlh; + struct rtmsg rtm; + struct rtattr rta; + unsigned int ifi; + } req = { + .nlh.nlmsg_type = RTM_GETROUTE, + .nlh.nlmsg_len = sizeof(req), + .nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP, + .nlh.nlmsg_seq = nl_seq++, + + .rtm.rtm_family = af, + .rtm.rtm_table = RT_TABLE_MAIN, + .rtm.rtm_scope = RT_SCOPE_UNIVERSE, + .rtm.rtm_type = RTN_UNICAST, + + .rta.rta_type = RTA_OIF, + .rta.rta_len = RTA_LENGTH(sizeof(unsigned int)), + .ifi = ifi, + }; + struct nlmsghdr *nh; + char buf[NLBUFSIZ]; + ssize_t n; + + if ((n = nl_req(0, buf, &req, req.nlh.nlmsg_len)) < 0) + return; + + for (nh = (struct nlmsghdr *)buf; + NLMSG_OK(nh, n) && nh->nlmsg_type != NLMSG_DONE; + nh = NLMSG_NEXT(nh, n)) { + struct rtmsg *rtm = (struct rtmsg *)NLMSG_DATA(nh); + struct rtattr *rta; + size_t na; + + if (nh->nlmsg_type != RTM_NEWROUTE) + continue; + + if (rtm->rtm_dst_len) + continue; + + for (rta = RTM_RTA(rtm), na = RTM_PAYLOAD(nh); RTA_OK(rta, na); + rta = RTA_NEXT(rta, na)) { + if (rta->rta_type != RTA_GATEWAY) + continue; + + memcpy(gw, RTA_DATA(rta), RTA_PAYLOAD(rta)); + return; + } + } +} + +/** + * nl_route_set_def() - Set default route for given interface and address family + * @ifi: Interface index in target namespace * @af: Address family - * @gw: Default gateway to fill on NL_GET, to set on NL_SET + * @gw: Default gateway to set */ -void nl_route(enum nl_op op, unsigned int ifi, unsigned int ifi_ns, - sa_family_t af, void *gw) +void nl_route_set_def(unsigned int ifi, sa_family_t af, void *gw) { struct req_t { struct nlmsghdr nlh; @@ -215,122 +271,125 @@ void nl_route(enum nl_op op, unsigned int ifi, unsigned int ifi_ns, } r4; } set; } req = { - .nlh.nlmsg_type = op == NL_SET ? RTM_NEWROUTE : RTM_GETROUTE, - .nlh.nlmsg_flags = NLM_F_REQUEST, + .nlh.nlmsg_type = RTM_NEWROUTE, + .nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | + NLM_F_CREATE | NLM_F_EXCL, .nlh.nlmsg_seq = nl_seq++, .rtm.rtm_family = af, .rtm.rtm_table = RT_TABLE_MAIN, .rtm.rtm_scope = RT_SCOPE_UNIVERSE, .rtm.rtm_type = RTN_UNICAST, + .rtm.rtm_protocol = RTPROT_BOOT, .rta.rta_type = RTA_OIF, .rta.rta_len = RTA_LENGTH(sizeof(unsigned int)), - .ifi = op == NL_SET ? ifi_ns : ifi, + .ifi = ifi, }; - unsigned dup_routes = 0; - ssize_t n, nlmsgs_size; - struct nlmsghdr *nh; - struct rtattr *rta; char buf[NLBUFSIZ]; - struct rtmsg *rtm; - size_t na; - - if (op == NL_SET) { - if (af == AF_INET6) { - size_t rta_len = RTA_LENGTH(sizeof(req.set.r6.d)); - req.nlh.nlmsg_len = offsetof(struct req_t, set.r6) - + sizeof(req.set.r6); + if (af == AF_INET6) { + size_t rta_len = RTA_LENGTH(sizeof(req.set.r6.d)); - req.set.r6.rta_dst.rta_type = RTA_DST; - req.set.r6.rta_dst.rta_len = rta_len; + req.nlh.nlmsg_len = offsetof(struct req_t, set.r6) + + sizeof(req.set.r6); - memcpy(&req.set.r6.a, gw, sizeof(req.set.r6.a)); - req.set.r6.rta_gw.rta_type = RTA_GATEWAY; - req.set.r6.rta_gw.rta_len = rta_len; - } else { - size_t rta_len = RTA_LENGTH(sizeof(req.set.r4.d)); + req.set.r6.rta_dst.rta_type = RTA_DST; + req.set.r6.rta_dst.rta_len = rta_len; - req.nlh.nlmsg_len = offsetof(struct req_t, set.r4) - + sizeof(req.set.r4); + memcpy(&req.set.r6.a, gw, sizeof(req.set.r6.a)); + req.set.r6.rta_gw.rta_type = RTA_GATEWAY; + req.set.r6.rta_gw.rta_len = rta_len; + } else { + size_t rta_len = RTA_LENGTH(sizeof(req.set.r4.d)); - req.set.r4.rta_dst.rta_type = RTA_DST; - req.set.r4.rta_dst.rta_len = rta_len; + req.nlh.nlmsg_len = offsetof(struct req_t, set.r4) + + sizeof(req.set.r4); - req.set.r4.a = *(uint32_t *)gw; - req.set.r4.rta_gw.rta_type = RTA_GATEWAY; - req.set.r4.rta_gw.rta_len = rta_len; - } + req.set.r4.rta_dst.rta_type = RTA_DST; + req.set.r4.rta_dst.rta_len = rta_len; - req.rtm.rtm_protocol = RTPROT_BOOT; - req.nlh.nlmsg_flags |= NLM_F_ACK | NLM_F_EXCL | NLM_F_CREATE; - } else { - req.nlh.nlmsg_len = offsetof(struct req_t, set.r6); - req.nlh.nlmsg_flags |= NLM_F_DUMP; + req.set.r4.a = *(uint32_t *)gw; + req.set.r4.rta_gw.rta_type = RTA_GATEWAY; + req.set.r4.rta_gw.rta_len = rta_len; } - if ((n = nl_req(op == NL_SET, buf, &req, req.nlh.nlmsg_len)) < 0) - return; + nl_req(1, buf, &req, req.nlh.nlmsg_len); +} - if (op == NL_SET) +/** + * nl_route_dup() - Copy routes for given interface and address family + * @ifi: Interface index in outer network namespace + * @ifi_ns: Interface index in target namespace for NL_SET, NL_DUP + * @af: Address family + */ +void nl_route_dup(unsigned int ifi, unsigned int ifi_ns, sa_family_t af) +{ + struct req_t { + struct nlmsghdr nlh; + struct rtmsg rtm; + struct rtattr rta; + unsigned int ifi; + } req = { + .nlh.nlmsg_type = RTM_GETROUTE, + .nlh.nlmsg_len = sizeof(req), + .nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP, + .nlh.nlmsg_seq = nl_seq++, + + .rtm.rtm_family = af, + .rtm.rtm_table = RT_TABLE_MAIN, + .rtm.rtm_scope = RT_SCOPE_UNIVERSE, + .rtm.rtm_type = RTN_UNICAST, + + .rta.rta_type = RTA_OIF, + .rta.rta_len = RTA_LENGTH(sizeof(unsigned int)), + .ifi = ifi, + }; + char buf[NLBUFSIZ], resp[NLBUFSIZ]; + unsigned dup_routes = 0; + ssize_t n, nlmsgs_size; + struct nlmsghdr *nh; + unsigned i; + + if ((n = nl_req(0, buf, &req, req.nlh.nlmsg_len)) < 0) return; - nh = (struct nlmsghdr *)buf; nlmsgs_size = n; - for ( ; NLMSG_OK(nh, n); nh = NLMSG_NEXT(nh, n)) { - if (nh->nlmsg_type != RTM_NEWROUTE) - goto next; - - if (op == NL_DUP) { - nh->nlmsg_seq = nl_seq++; - nh->nlmsg_pid = 0; - nh->nlmsg_flags &= ~NLM_F_DUMP_FILTERED; - nh->nlmsg_flags |= NLM_F_REQUEST | NLM_F_ACK | - NLM_F_CREATE; - dup_routes++; - } + for (nh = (struct nlmsghdr *)buf; + NLMSG_OK(nh, n) && nh->nlmsg_type != NLMSG_DONE; + nh = NLMSG_NEXT(nh, n)) { + struct rtmsg *rtm = (struct rtmsg *)NLMSG_DATA(nh); + struct rtattr *rta; + size_t na; - rtm = (struct rtmsg *)NLMSG_DATA(nh); - if (op == NL_GET && rtm->rtm_dst_len) + if (nh->nlmsg_type != RTM_NEWROUTE) continue; + nh->nlmsg_seq = nl_seq++; + nh->nlmsg_pid = 0; + nh->nlmsg_flags &= ~NLM_F_DUMP_FILTERED; + nh->nlmsg_flags |= NLM_F_REQUEST | NLM_F_ACK | + NLM_F_CREATE; + dup_routes++; + for (rta = RTM_RTA(rtm), na = RTM_PAYLOAD(nh); RTA_OK(rta, na); rta = RTA_NEXT(rta, na)) { - if (op == NL_GET) { - if (rta->rta_type != RTA_GATEWAY) - continue; - - memcpy(gw, RTA_DATA(rta), RTA_PAYLOAD(rta)); - return; - } - - if (op == NL_DUP && rta->rta_type == RTA_OIF) + if (rta->rta_type == RTA_OIF) *(unsigned int *)RTA_DATA(rta) = ifi_ns; } - -next: - if (nh->nlmsg_type == NLMSG_DONE) - break; } - if (op == NL_DUP) { - char resp[NLBUFSIZ]; - unsigned i; - - nh = (struct nlmsghdr *)buf; - /* Routes might have dependencies between each other, and the - * kernel processes RTM_NEWROUTE messages sequentially. For n - * valid routes, we might need to send up to n requests to get - * all of them inserted. Routes that have been already inserted - * won't cause the whole request to fail, so we can simply - * repeat the whole request. This approach avoids the need to - * calculate dependencies: let the kernel do that. - */ - for (i = 0; i < dup_routes; i++) - nl_req(1, resp, nh, nlmsgs_size); - } + nh = (struct nlmsghdr *)buf; + /* Routes might have dependencies between each other, and the kernel + * processes RTM_NEWROUTE messages sequentially. For n valid routes, we + * might need to send up to n requests to get all of them inserted. + * Routes that have been already inserted won't cause the whole request + * to fail, so we can simply repeat the whole request. This approach + * avoids the need to calculate dependencies: let the kernel do that. + */ + for (i = 0; i < dup_routes; i++) + nl_req(1, resp, nh, nlmsgs_size); } /** |