diff options
Diffstat (limited to 'nhrpd/netlink_gre.c')
| -rw-r--r-- | nhrpd/netlink_gre.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/nhrpd/netlink_gre.c b/nhrpd/netlink_gre.c new file mode 100644 index 0000000000..93998dc5f5 --- /dev/null +++ b/nhrpd/netlink_gre.c @@ -0,0 +1,142 @@ +/* NHRP netlink/GRE tunnel configuration code + * Copyright (c) 2014-2016 Timo Teräs + * + * This file is free software: you may copy, redistribute and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + */ + +#include <sys/socket.h> +#include <linux/netlink.h> +#include <linux/rtnetlink.h> +#include <linux/in.h> +#include <linux/if.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/if_tunnel.h> + +#include "debug.h" +#include "netlink.h" +#include "znl.h" + +static int __netlink_gre_get_data(struct zbuf *zb, struct zbuf *data, int ifindex) +{ + struct nlmsghdr *n; + struct ifinfomsg *ifi; + struct zbuf payload, rtapayload; + struct rtattr *rta; + + debugf(NHRP_DEBUG_KERNEL, "netlink-link-gre: get-info %u", ifindex); + + n = znl_nlmsg_push(zb, RTM_GETLINK, NLM_F_REQUEST); + ifi = znl_push(zb, sizeof(*ifi)); + *ifi = (struct ifinfomsg) { + .ifi_index = ifindex, + }; + znl_nlmsg_complete(zb, n); + + if (zbuf_send(zb, netlink_req_fd) < 0 || + zbuf_recv(zb, netlink_req_fd) < 0) + return -1; + + n = znl_nlmsg_pull(zb, &payload); + if (!n) return -1; + + if (n->nlmsg_type != RTM_NEWLINK) + return -1; + + ifi = znl_pull(&payload, sizeof(struct ifinfomsg)); + if (!ifi) + return -1; + + debugf(NHRP_DEBUG_KERNEL, "netlink-link-gre: ifindex %u, receive msg_type %u, msg_flags %u", + ifi->ifi_index, n->nlmsg_type, n->nlmsg_flags); + + if (ifi->ifi_index != ifindex) + return -1; + + while ((rta = znl_rta_pull(&payload, &rtapayload)) != NULL) + if (rta->rta_type == IFLA_LINKINFO) + break; + if (!rta) return -1; + + payload = rtapayload; + while ((rta = znl_rta_pull(&payload, &rtapayload)) != NULL) + if (rta->rta_type == IFLA_INFO_DATA) + break; + if (!rta) return -1; + + *data = rtapayload; + return 0; +} + +void netlink_gre_get_info(unsigned int ifindex, uint32_t *gre_key, unsigned int *link_index, struct in_addr *saddr) +{ + struct zbuf *zb = zbuf_alloc(8192), data, rtapl; + struct rtattr *rta; + + *link_index = 0; + *gre_key = 0; + saddr->s_addr = 0; + + if (__netlink_gre_get_data(zb, &data, ifindex) < 0) + goto err; + + while ((rta = znl_rta_pull(&data, &rtapl)) != NULL) { + switch (rta->rta_type) { + case IFLA_GRE_LINK: + *link_index = zbuf_get32(&rtapl); + break; + case IFLA_GRE_IKEY: + case IFLA_GRE_OKEY: + *gre_key = zbuf_get32(&rtapl); + break; + case IFLA_GRE_LOCAL: + saddr->s_addr = zbuf_get32(&rtapl); + break; + } + } +err: + zbuf_free(zb); +} + +void netlink_gre_set_link(unsigned int ifindex, unsigned int link_index) +{ + struct nlmsghdr *n; + struct ifinfomsg *ifi; + struct rtattr *rta_info, *rta_data, *rta; + struct zbuf *zr = zbuf_alloc(8192), data, rtapl; + struct zbuf *zb = zbuf_alloc(8192); + size_t len; + + if (__netlink_gre_get_data(zr, &data, ifindex) < 0) + goto err; + + n = znl_nlmsg_push(zb, RTM_NEWLINK, NLM_F_REQUEST); + ifi = znl_push(zb, sizeof(*ifi)); + *ifi = (struct ifinfomsg) { + .ifi_index = ifindex, + }; + rta_info = znl_rta_nested_push(zb, IFLA_LINKINFO); + znl_rta_push(zb, IFLA_INFO_KIND, "gre", 3); + rta_data = znl_rta_nested_push(zb, IFLA_INFO_DATA); + + znl_rta_push_u32(zb, IFLA_GRE_LINK, link_index); + while ((rta = znl_rta_pull(&data, &rtapl)) != NULL) { + if (rta->rta_type == IFLA_GRE_LINK) + continue; + len = zbuf_used(&rtapl); + znl_rta_push(zb, rta->rta_type, zbuf_pulln(&rtapl, len), len); + } + + znl_rta_nested_complete(zb, rta_data); + znl_rta_nested_complete(zb, rta_info); + + znl_nlmsg_complete(zb, n); + zbuf_send(zb, netlink_req_fd); + zbuf_recv(zb, netlink_req_fd); +err: + zbuf_free(zb); + zbuf_free(zr); +} |