From a54cee0d033ada75724b18a9350103a02e0ba956 Mon Sep 17 00:00:00 2001 From: Hans Dedecker Date: Thu, 7 Feb 2019 13:18:40 +0100 Subject: [PATCH] netlink: rework handling of netlink messages Multiple logical OpenWrt interfaces can be stacked on top of the same Linux device. As such netlink events for addresses/routes/ifindex changes need to be propagated to the different logical OpenWrt interfaces which use the Linux device as reported in the netlink message. Signed-off-by: Hans Dedecker --- src/netlink.c | 384 +++++++++++++++++++++++++++++++++----------------- src/odhcpd.c | 14 -- src/odhcpd.h | 1 - 3 files changed, 252 insertions(+), 147 deletions(-) diff --git a/src/netlink.c b/src/netlink.c index 9ed91b1..abd326e 100644 --- a/src/netlink.c +++ b/src/netlink.c @@ -129,222 +129,342 @@ static void handle_rtnl_event(struct odhcpd_event *e) nl_recvmsgs_default(ev_sock->sock); } -static void refresh_iface_addr4(struct netevent_handler_info *event_info) +static void refresh_iface_addr4(int ifindex) { struct odhcpd_ipaddr *addr = NULL; - struct interface *iface = event_info->iface; - ssize_t len = netlink_get_interface_addrs(iface->ifindex, false, &addr); + struct interface *iface; + ssize_t len = netlink_get_interface_addrs(ifindex, false, &addr); + bool change = false; if (len < 0) return; - bool change = len != (ssize_t)iface->addr4_len; - for (ssize_t i = 0; !change && i < len; ++i) - if (addr[i].addr.in.s_addr != iface->addr4[i].addr.in.s_addr) - change = true; + avl_for_each_element(&interfaces, iface, avl) { + if (iface->ifindex != ifindex) + continue; - event_info->addrs_old.addrs = iface->addr4; - event_info->addrs_old.len = iface->addr4_len; + change = len != (ssize_t)iface->addr4_len; + for (ssize_t i = 0; !change && i < len; ++i) { + if (addr[i].addr.in.s_addr != iface->addr4[i].addr.in.s_addr) + change = true; + } + break; + } + + if (!change) { + free(addr); + return; + } + + avl_for_element_range(iface, avl_last_element(&interfaces, iface, avl), iface, avl) { + struct netevent_handler_info event_info; + + if (iface->ifindex != ifindex) + continue; + + memset(&event_info, 0, sizeof(event_info)); + event_info.iface = iface; + event_info.addrs_old.addrs = iface->addr4; + event_info.addrs_old.len = iface->addr4_len; - iface->addr4 = addr; - iface->addr4_len = len; + iface->addr4 = addr; + iface->addr4_len = len; - if (change) - call_netevent_handler_list(NETEV_ADDRLIST_CHANGE, event_info); + call_netevent_handler_list(NETEV_ADDRLIST_CHANGE, &event_info); - free(event_info->addrs_old.addrs); + free(event_info.addrs_old.addrs); + + if (len) { + addr = malloc(len * sizeof(*addr)); + if (!addr) + return; + + memcpy(addr, iface->addr4, len * sizeof(*addr)); + } + } + + free(addr); } -static void refresh_iface_addr6(struct netevent_handler_info *event_info) +static void refresh_iface_addr6(int ifindex) { struct odhcpd_ipaddr *addr = NULL; - struct interface *iface = event_info->iface; - ssize_t len = netlink_get_interface_addrs(iface->ifindex, true, &addr); + struct interface *iface; + ssize_t len = netlink_get_interface_addrs(ifindex, true, &addr); time_t now = odhcpd_time(); + bool change = false; if (len < 0) return; - bool change = len != (ssize_t)iface->addr6_len; - for (ssize_t i = 0; !change && i < len; ++i) - if (!IN6_ARE_ADDR_EQUAL(&addr[i].addr.in6, &iface->addr6[i].addr.in6) || - (addr[i].preferred > (uint32_t)now) != (iface->addr6[i].preferred > (uint32_t)now) || - addr[i].valid < iface->addr6[i].valid || - addr[i].preferred < iface->addr6[i].preferred) - change = true; + avl_for_each_element(&interfaces, iface, avl) { + if (iface->ifindex != ifindex) + continue; - event_info->addrs_old.addrs = iface->addr6; - event_info->addrs_old.len = iface->addr6_len; + change = len != (ssize_t)iface->addr6_len; + for (ssize_t i = 0; !change && i < len; ++i) { + if (!IN6_ARE_ADDR_EQUAL(&addr[i].addr.in6, &iface->addr6[i].addr.in6) || + (addr[i].preferred > (uint32_t)now) != (iface->addr6[i].preferred > (uint32_t)now) || + addr[i].valid < iface->addr6[i].valid || addr[i].preferred < iface->addr6[i].preferred) + change = true; + } + break; + } - iface->addr6 = addr; - iface->addr6_len = len; + if (!change) { + free(addr); + return; + } + + avl_for_element_range(iface, avl_last_element(&interfaces, iface, avl), iface, avl) { + struct netevent_handler_info event_info; + + if (iface->ifindex != ifindex) + continue; + + memset(&event_info, 0, sizeof(event_info)); + event_info.iface = iface; + event_info.addrs_old.addrs = iface->addr6; + event_info.addrs_old.len = iface->addr6_len; + + iface->addr6 = addr; + iface->addr6_len = len; + + call_netevent_handler_list(NETEV_ADDR6LIST_CHANGE, &event_info); + + free(event_info.addrs_old.addrs); - if (change) - call_netevent_handler_list(NETEV_ADDR6LIST_CHANGE, event_info); + if (len) { + addr = malloc(len * sizeof(*addr)); + if (!addr) + return; - free(event_info->addrs_old.addrs); + memcpy(addr, iface->addr6, len * sizeof(*addr)); + } + } + + free(addr); } -/* Handler for neighbor cache entries from the kernel. This is our source - * to learn and unlearn hosts on interfaces. */ -static int cb_rtnl_valid(struct nl_msg *msg, _unused void *arg) +static int handle_rtm_link(struct nlmsghdr *hdr) { - struct nlmsghdr *hdr = nlmsg_hdr(msg); + struct ifinfomsg *ifi = nlmsg_data(hdr); + struct nlattr *nla[__IFLA_MAX]; + struct interface *iface; struct netevent_handler_info event_info; - bool add = false; - char ipbuf[INET6_ADDRSTRLEN]; + const char *ifname; memset(&event_info, 0, sizeof(event_info)); - switch (hdr->nlmsg_type) { - case RTM_NEWLINK: { - struct ifinfomsg *ifi = nlmsg_data(hdr); - struct nlattr *nla[__IFLA_MAX]; - if (!nlmsg_valid_hdr(hdr, sizeof(*ifi)) || - ifi->ifi_family != AF_UNSPEC) - return NL_SKIP; + if (!nlmsg_valid_hdr(hdr, sizeof(*ifi)) || ifi->ifi_family != AF_UNSPEC) + return NL_SKIP; - nlmsg_parse(hdr, sizeof(*ifi), nla, __IFLA_MAX - 1, NULL); - if (!nla[IFLA_IFNAME]) - return NL_SKIP; + nlmsg_parse(hdr, sizeof(*ifi), nla, __IFLA_MAX - 1, NULL); + if (!nla[IFLA_IFNAME]) + return NL_SKIP; - event_info.iface = odhcpd_get_interface_by_name(nla_get_string(nla[IFLA_IFNAME])); - if (!event_info.iface) - return NL_SKIP; + ifname = nla_get_string(nla[IFLA_IFNAME]); - if (event_info.iface->ifindex != ifi->ifi_index) { - event_info.iface->ifindex = ifi->ifi_index; - call_netevent_handler_list(NETEV_IFINDEX_CHANGE, &event_info); - } - break; + avl_for_each_element(&interfaces, iface, avl) { + if (strcmp(iface->ifname, ifname) || iface->ifindex == ifi->ifi_index) + continue; + + iface->ifindex = ifi->ifi_index; + event_info.iface = iface; + call_netevent_handler_list(NETEV_IFINDEX_CHANGE, &event_info); } - case RTM_NEWROUTE: - add = true; - /* fall through */ - case RTM_DELROUTE: { - struct rtmsg *rtm = nlmsg_data(hdr); - struct nlattr *nla[__RTA_MAX]; + return NL_OK; +} - if (!nlmsg_valid_hdr(hdr, sizeof(*rtm)) || - rtm->rtm_family != AF_INET6) - return NL_SKIP; +static int handle_rtm_route(struct nlmsghdr *hdr, bool add) +{ + struct rtmsg *rtm = nlmsg_data(hdr); + struct nlattr *nla[__RTA_MAX]; + struct interface *iface; + struct netevent_handler_info event_info; + int ifindex = 0; - nlmsg_parse(hdr, sizeof(*rtm), nla, __RTA_MAX - 1, NULL); + if (!nlmsg_valid_hdr(hdr, sizeof(*rtm)) || rtm->rtm_family != AF_INET6) + return NL_SKIP; + + nlmsg_parse(hdr, sizeof(*rtm), nla, __RTA_MAX - 1, NULL); + + memset(&event_info, 0, sizeof(event_info)); + event_info.rt.dst_len = rtm->rtm_dst_len; - event_info.rt.dst_len = rtm->rtm_dst_len; - if (nla[RTA_DST]) - nla_memcpy(&event_info.rt.dst, nla[RTA_DST], - sizeof(event_info.rt.dst)); + if (nla[RTA_DST]) + nla_memcpy(&event_info.rt.dst, nla[RTA_DST], + sizeof(event_info.rt.dst)); - if (nla[RTA_OIF]) - event_info.iface = odhcpd_get_interface_by_index(nla_get_u32(nla[RTA_OIF])); + if (nla[RTA_OIF]) + ifindex = nla_get_u32(nla[RTA_OIF]); - if (nla[RTA_GATEWAY]) - nla_memcpy(&event_info.rt.gateway, nla[RTA_GATEWAY], - sizeof(event_info.rt.gateway)); + if (nla[RTA_GATEWAY]) + nla_memcpy(&event_info.rt.gateway, nla[RTA_GATEWAY], + sizeof(event_info.rt.gateway)); + avl_for_each_element(&interfaces, iface, avl) { + if (ifindex && iface->ifindex != ifindex) + continue; + + event_info.iface = ifindex ? iface : NULL; call_netevent_handler_list(add ? NETEV_ROUTE6_ADD : NETEV_ROUTE6_DEL, - &event_info); - break; + &event_info); } - case RTM_NEWADDR: - add = true; - /* fall through */ - case RTM_DELADDR: { - struct ifaddrmsg *ifa = nlmsg_data(hdr); - struct nlattr *nla[__IFA_MAX]; + return NL_OK; +} - if (!nlmsg_valid_hdr(hdr, sizeof(*ifa)) || - (ifa->ifa_family != AF_INET6 && - ifa->ifa_family != AF_INET)) - return NL_SKIP; +static int handle_rtm_addr(struct nlmsghdr *hdr, bool add) +{ + struct ifaddrmsg *ifa = nlmsg_data(hdr); + struct nlattr *nla[__IFA_MAX]; + struct interface *iface; + struct netevent_handler_info event_info; + char buf[INET6_ADDRSTRLEN]; - event_info.iface = odhcpd_get_interface_by_index(ifa->ifa_index); - if (!event_info.iface) + if (!nlmsg_valid_hdr(hdr, sizeof(*ifa)) || + (ifa->ifa_family != AF_INET6 && + ifa->ifa_family != AF_INET)) + return NL_SKIP; + + memset(&event_info, 0, sizeof(event_info)); + + nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL); + + if (ifa->ifa_family == AF_INET6) { + if (!nla[IFA_ADDRESS]) return NL_SKIP; - nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL); + nla_memcpy(&event_info.addr, nla[IFA_ADDRESS], sizeof(event_info.addr)); - if (ifa->ifa_family == AF_INET6) { - if (!nla[IFA_ADDRESS]) - return NL_SKIP; + if (IN6_IS_ADDR_LINKLOCAL(&event_info.addr) || IN6_IS_ADDR_MULTICAST(&event_info.addr)) + return NL_SKIP; - nla_memcpy(&event_info.addr, nla[IFA_ADDRESS], sizeof(event_info.addr)); + inet_ntop(AF_INET6, &event_info.addr, buf, sizeof(buf)); - if (IN6_IS_ADDR_LINKLOCAL(&event_info.addr) || - IN6_IS_ADDR_MULTICAST(&event_info.addr)) - return NL_SKIP; + avl_for_each_element(&interfaces, iface, avl) { + if (iface->ifindex != (int)ifa->ifa_index) + continue; - inet_ntop(AF_INET6, &event_info.addr, ipbuf, sizeof(ipbuf)); syslog(LOG_DEBUG, "Netlink %s %s on %s", add ? "newaddr" : "deladdr", - ipbuf, event_info.iface->name); + buf, iface->name); + event_info.iface = iface; call_netevent_handler_list(add ? NETEV_ADDR6_ADD : NETEV_ADDR6_DEL, &event_info); + } - refresh_iface_addr6(&event_info); - } else { - if (!nla[IFA_LOCAL]) - return NL_SKIP; + refresh_iface_addr6(ifa->ifa_index); + } else { + if (!nla[IFA_LOCAL]) + return NL_SKIP; - nla_memcpy(&event_info.addr, nla[IFA_LOCAL], sizeof(event_info.addr)); + nla_memcpy(&event_info.addr, nla[IFA_LOCAL], sizeof(event_info.addr)); + + inet_ntop(AF_INET, &event_info.addr, buf, sizeof(buf)); + + avl_for_each_element(&interfaces, iface, avl) { + if (iface->ifindex != (int)ifa->ifa_index) + continue; - inet_ntop(AF_INET, &event_info.addr, ipbuf, sizeof(ipbuf)); syslog(LOG_DEBUG, "Netlink %s %s on %s", add ? "newaddr" : "deladdr", - ipbuf, event_info.iface->name); + buf, iface->name); + event_info.iface = iface; call_netevent_handler_list(add ? NETEV_ADDR_ADD : NETEV_ADDR_DEL, &event_info); - - refresh_iface_addr4(&event_info); } - break; + + refresh_iface_addr4(ifa->ifa_index); } - case RTM_NEWNEIGH: - add = true; - /* fall through */ - case RTM_DELNEIGH: { - struct ndmsg *ndm = nlmsg_data(hdr); - struct nlattr *nla[__NDA_MAX]; + return NL_OK; +} - if (!nlmsg_valid_hdr(hdr, sizeof(*ndm)) || - ndm->ndm_family != AF_INET6) - return NL_SKIP; +static int handle_rtm_neigh(struct nlmsghdr *hdr, bool add) +{ + struct ndmsg *ndm = nlmsg_data(hdr); + struct nlattr *nla[__NDA_MAX]; + struct interface *iface; + struct netevent_handler_info event_info; + char buf[INET6_ADDRSTRLEN]; - event_info.iface = odhcpd_get_interface_by_index(ndm->ndm_ifindex); - if (!event_info.iface) - return NL_SKIP; + if (!nlmsg_valid_hdr(hdr, sizeof(*ndm)) || + ndm->ndm_family != AF_INET6) + return NL_SKIP; - nlmsg_parse(hdr, sizeof(*ndm), nla, __NDA_MAX - 1, NULL); - if (!nla[NDA_DST]) - return NL_SKIP; + nlmsg_parse(hdr, sizeof(*ndm), nla, __NDA_MAX - 1, NULL); + if (!nla[NDA_DST]) + return NL_SKIP; + + memset(&event_info, 0, sizeof(event_info)); - nla_memcpy(&event_info.neigh.dst, nla[NDA_DST], sizeof(event_info.neigh.dst)); + nla_memcpy(&event_info.neigh.dst, nla[NDA_DST], sizeof(event_info.neigh.dst)); - if (IN6_IS_ADDR_LINKLOCAL(&event_info.neigh.dst) || - IN6_IS_ADDR_MULTICAST(&event_info.neigh.dst)) - return NL_SKIP; + if (IN6_IS_ADDR_LINKLOCAL(&event_info.neigh.dst) || + IN6_IS_ADDR_MULTICAST(&event_info.neigh.dst)) + return NL_SKIP; + + inet_ntop(AF_INET6, &event_info.neigh.dst, buf, sizeof(buf)); + + avl_for_each_element(&interfaces, iface, avl) { + if (iface->ifindex != ndm->ndm_ifindex) + continue; - inet_ntop(AF_INET6, &event_info.neigh.dst, ipbuf, sizeof(ipbuf)); syslog(LOG_DEBUG, "Netlink %s %s on %s", true ? "newneigh" : "delneigh", - ipbuf, event_info.iface->name); + buf, iface->name); event_info.neigh.state = ndm->ndm_state; event_info.neigh.flags = ndm->ndm_flags; call_netevent_handler_list(add ? NETEV_NEIGH6_ADD : NETEV_NEIGH6_DEL, &event_info); - break; } + return NL_OK; +} + +/* Handler for neighbor cache entries from the kernel. This is our source + * to learn and unlearn hosts on interfaces. */ +static int cb_rtnl_valid(struct nl_msg *msg, _unused void *arg) +{ + struct nlmsghdr *hdr = nlmsg_hdr(msg); + int ret = NL_SKIP; + bool add = false; + + switch (hdr->nlmsg_type) { + case RTM_NEWLINK: + ret = handle_rtm_link(hdr); + break; + + case RTM_NEWROUTE: + add = true; + /* fall through */ + case RTM_DELROUTE: + ret = handle_rtm_route(hdr, add); + break; + + case RTM_NEWADDR: + add = true; + /* fall through */ + case RTM_DELADDR: + ret = handle_rtm_addr(hdr, add); + break; + + case RTM_NEWNEIGH: + add = true; + /* fall through */ + case RTM_DELNEIGH: + ret = handle_rtm_neigh(hdr, add); + break; + default: - return NL_SKIP; + break; } - return NL_OK; + return ret; } static void catch_rtnl_err(struct odhcpd_event *e, int error) diff --git a/src/odhcpd.c b/src/odhcpd.c index 46878f7..fafa3f6 100644 --- a/src/odhcpd.c +++ b/src/odhcpd.c @@ -300,20 +300,6 @@ struct interface* odhcpd_get_interface_by_index(int ifindex) return NULL; } - -struct interface* odhcpd_get_interface_by_name(const char *name) -{ - struct interface *iface; - - avl_for_each_element(&interfaces, iface, avl) { - if (!strcmp(iface->ifname, name)) - return iface; - } - - return NULL; -} - - struct interface* odhcpd_get_master_interface(void) { struct interface *iface; diff --git a/src/odhcpd.h b/src/odhcpd.h index a1d89e8..f32f34b 100644 --- a/src/odhcpd.h +++ b/src/odhcpd.h @@ -263,7 +263,6 @@ ssize_t odhcpd_send(int socket, struct sockaddr_in6 *dest, const struct interface *iface); int odhcpd_get_interface_dns_addr(const struct interface *iface, struct in6_addr *addr); -struct interface* odhcpd_get_interface_by_name(const char *name); int odhcpd_get_interface_config(const char *ifname, const char *what); int odhcpd_get_mac(const struct interface *iface, uint8_t mac[6]); struct interface* odhcpd_get_interface_by_index(int ifindex); -- 2.30.2