diff options
Diffstat (limited to 'zebra/kernel_netlink.c')
| -rw-r--r-- | zebra/kernel_netlink.c | 1946 |
1 files changed, 1946 insertions, 0 deletions
diff --git a/zebra/kernel_netlink.c b/zebra/kernel_netlink.c new file mode 100644 index 0000000..7c934ed --- /dev/null +++ b/zebra/kernel_netlink.c @@ -0,0 +1,1946 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Kernel communication using netlink interface. + * Copyright (C) 1999 Kunihiro Ishiguro + */ + +#include <zebra.h> + +#ifdef HAVE_NETLINK + +#include "linklist.h" +#include "if.h" +#include "log.h" +#include "prefix.h" +#include "connected.h" +#include "table.h" +#include "memory.h" +#include "rib.h" +#include "frrevent.h" +#include "privs.h" +#include "nexthop.h" +#include "vrf.h" +#include "mpls.h" +#include "lib_errors.h" +#include "hash.h" + +#include "zebra/zebra_router.h" +#include "zebra/zebra_ns.h" +#include "zebra/zebra_vrf.h" +#include "zebra/rt.h" +#include "zebra/debug.h" +#include "zebra/kernel_netlink.h" +#include "zebra/rt_netlink.h" +#include "zebra/if_netlink.h" +#include "zebra/rule_netlink.h" +#include "zebra/tc_netlink.h" +#include "zebra/netconf_netlink.h" +#include "zebra/zebra_errors.h" + +#ifndef SO_RCVBUFFORCE +#define SO_RCVBUFFORCE (33) +#endif + +/* Hack for GNU libc version 2. */ +#ifndef MSG_TRUNC +#define MSG_TRUNC 0x20 +#endif /* MSG_TRUNC */ + +#ifndef NLMSG_TAIL +#define NLMSG_TAIL(nmsg) \ + ((struct rtattr *)(((uint8_t *)(nmsg)) \ + + NLMSG_ALIGN((nmsg)->nlmsg_len))) +#endif + +#ifndef RTA_TAIL +#define RTA_TAIL(rta) \ + ((struct rtattr *)(((uint8_t *)(rta)) + RTA_ALIGN((rta)->rta_len))) +#endif + +#ifndef RTNL_FAMILY_IP6MR +#define RTNL_FAMILY_IP6MR 129 +#endif + +#ifndef RTPROT_MROUTED +#define RTPROT_MROUTED 17 +#endif + +#define NL_DEFAULT_BATCH_BUFSIZE (16 * NL_PKT_BUF_SIZE) + +/* + * We limit the batch's size to a number smaller than the length of the + * underlying buffer since the last message that wouldn't fit the batch would go + * over the upper boundary and then it would have to be encoded again into a new + * buffer. If the difference between the limit and the length of the buffer is + * big enough (bigger than the biggest Netlink message) then this situation + * won't occur. + */ +#define NL_DEFAULT_BATCH_SEND_THRESHOLD (15 * NL_PKT_BUF_SIZE) + +static const struct message nlmsg_str[] = {{RTM_NEWROUTE, "RTM_NEWROUTE"}, + {RTM_DELROUTE, "RTM_DELROUTE"}, + {RTM_GETROUTE, "RTM_GETROUTE"}, + {RTM_NEWLINK, "RTM_NEWLINK"}, + {RTM_SETLINK, "RTM_SETLINK"}, + {RTM_DELLINK, "RTM_DELLINK"}, + {RTM_GETLINK, "RTM_GETLINK"}, + {RTM_NEWADDR, "RTM_NEWADDR"}, + {RTM_DELADDR, "RTM_DELADDR"}, + {RTM_GETADDR, "RTM_GETADDR"}, + {RTM_NEWNEIGH, "RTM_NEWNEIGH"}, + {RTM_DELNEIGH, "RTM_DELNEIGH"}, + {RTM_GETNEIGH, "RTM_GETNEIGH"}, + {RTM_NEWRULE, "RTM_NEWRULE"}, + {RTM_DELRULE, "RTM_DELRULE"}, + {RTM_GETRULE, "RTM_GETRULE"}, + {RTM_NEWNEXTHOP, "RTM_NEWNEXTHOP"}, + {RTM_DELNEXTHOP, "RTM_DELNEXTHOP"}, + {RTM_GETNEXTHOP, "RTM_GETNEXTHOP"}, + {RTM_NEWNETCONF, "RTM_NEWNETCONF"}, + {RTM_DELNETCONF, "RTM_DELNETCONF"}, + {RTM_NEWTUNNEL, "RTM_NEWTUNNEL"}, + {RTM_DELTUNNEL, "RTM_DELTUNNEL"}, + {RTM_GETTUNNEL, "RTM_GETTUNNEL"}, + {RTM_NEWQDISC, "RTM_NEWQDISC"}, + {RTM_DELQDISC, "RTM_DELQDISC"}, + {RTM_GETQDISC, "RTM_GETQDISC"}, + {RTM_NEWTCLASS, "RTM_NEWTCLASS"}, + {RTM_DELTCLASS, "RTM_DELTCLASS"}, + {RTM_GETTCLASS, "RTM_GETTCLASS"}, + {RTM_NEWTFILTER, "RTM_NEWTFILTER"}, + {RTM_DELTFILTER, "RTM_DELTFILTER"}, + {RTM_GETTFILTER, "RTM_GETTFILTER"}, + {RTM_NEWVLAN, "RTM_NEWVLAN"}, + {RTM_DELVLAN, "RTM_DELVLAN"}, + {RTM_GETVLAN, "RTM_GETVLAN"}, + {0}}; + +static const struct message rtproto_str[] = { + {RTPROT_REDIRECT, "redirect"}, + {RTPROT_KERNEL, "kernel"}, + {RTPROT_BOOT, "boot"}, + {RTPROT_STATIC, "static"}, + {RTPROT_GATED, "GateD"}, + {RTPROT_RA, "router advertisement"}, + {RTPROT_MRT, "MRT"}, + {RTPROT_ZEBRA, "Zebra"}, +#ifdef RTPROT_BIRD + {RTPROT_BIRD, "BIRD"}, +#endif /* RTPROT_BIRD */ + {RTPROT_MROUTED, "mroute"}, + {RTPROT_BGP, "BGP"}, + {RTPROT_OSPF, "OSPF"}, + {RTPROT_ISIS, "IS-IS"}, + {RTPROT_RIP, "RIP"}, + {RTPROT_RIPNG, "RIPNG"}, + {RTPROT_ZSTATIC, "static"}, + {0}}; + +static const struct message family_str[] = {{AF_INET, "ipv4"}, + {AF_INET6, "ipv6"}, + {AF_BRIDGE, "bridge"}, + {RTNL_FAMILY_IPMR, "ipv4MR"}, + {RTNL_FAMILY_IP6MR, "ipv6MR"}, + {0}}; + +static const struct message rttype_str[] = {{RTN_UNSPEC, "none"}, + {RTN_UNICAST, "unicast"}, + {RTN_LOCAL, "local"}, + {RTN_BROADCAST, "broadcast"}, + {RTN_ANYCAST, "anycast"}, + {RTN_MULTICAST, "multicast"}, + {RTN_BLACKHOLE, "blackhole"}, + {RTN_UNREACHABLE, "unreachable"}, + {RTN_PROHIBIT, "prohibited"}, + {RTN_THROW, "throw"}, + {RTN_NAT, "nat"}, + {RTN_XRESOLVE, "resolver"}, + {0}}; + +extern struct event_loop *master; + +extern struct zebra_privs_t zserv_privs; + +DEFINE_MTYPE_STATIC(ZEBRA, NL_BUF, "Zebra Netlink buffers"); + +/* Hashtable and mutex to allow lookup of nlsock structs by socket/fd value. + * We have both the main and dplane pthreads using these structs, so we have + * to protect the hash with a lock. + */ +static struct hash *nlsock_hash; +pthread_mutex_t nlsock_mutex; + +/* Lock and unlock wrappers for nlsock hash */ +#define NLSOCK_LOCK() pthread_mutex_lock(&nlsock_mutex) +#define NLSOCK_UNLOCK() pthread_mutex_unlock(&nlsock_mutex) + +size_t nl_batch_tx_bufsize; +char *nl_batch_tx_buf; + +_Atomic uint32_t nl_batch_bufsize = NL_DEFAULT_BATCH_BUFSIZE; +_Atomic uint32_t nl_batch_send_threshold = NL_DEFAULT_BATCH_SEND_THRESHOLD; + +struct nl_batch { + void *buf; + size_t bufsiz; + size_t limit; + + void *buf_head; + size_t curlen; + size_t msgcnt; + + const struct zebra_dplane_info *zns; + + struct dplane_ctx_list_head ctx_list; + + /* + * Pointer to the queue of completed contexts outbound back + * towards the dataplane module. + */ + struct dplane_ctx_list_head *ctx_out_q; +}; + +int netlink_config_write_helper(struct vty *vty) +{ + uint32_t size = + atomic_load_explicit(&nl_batch_bufsize, memory_order_relaxed); + uint32_t threshold = atomic_load_explicit(&nl_batch_send_threshold, + memory_order_relaxed); + + if (size != NL_DEFAULT_BATCH_BUFSIZE + || threshold != NL_DEFAULT_BATCH_SEND_THRESHOLD) + vty_out(vty, "zebra kernel netlink batch-tx-buf %u %u\n", size, + threshold); + + if (if_netlink_frr_protodown_r_bit_is_set()) + vty_out(vty, "zebra protodown reason-bit %u\n", + if_netlink_get_frr_protodown_r_bit()); + + return 0; +} + +void netlink_set_batch_buffer_size(uint32_t size, uint32_t threshold, bool set) +{ + if (!set) { + size = NL_DEFAULT_BATCH_BUFSIZE; + threshold = NL_DEFAULT_BATCH_SEND_THRESHOLD; + } + + atomic_store_explicit(&nl_batch_bufsize, size, memory_order_relaxed); + atomic_store_explicit(&nl_batch_send_threshold, threshold, + memory_order_relaxed); +} + +int netlink_talk_filter(struct nlmsghdr *h, ns_id_t ns_id, int startup) +{ + /* + * This is an error condition that must be handled during + * development. + * + * The netlink_talk_filter function is used for communication + * down the netlink_cmd pipe and we are expecting + * an ack being received. So if we get here + * then we did not receive the ack and instead + * received some other message in an unexpected + * way. + */ + zlog_debug("%s: ignoring message type 0x%04x(%s) NS %u", __func__, + h->nlmsg_type, nl_msg_type_to_str(h->nlmsg_type), ns_id); + return 0; +} + +static int netlink_recvbuf(struct nlsock *nl, uint32_t newsize) +{ + uint32_t oldsize; + socklen_t newlen = sizeof(newsize); + socklen_t oldlen = sizeof(oldsize); + int ret; + + ret = getsockopt(nl->sock, SOL_SOCKET, SO_RCVBUF, &oldsize, &oldlen); + if (ret < 0) { + flog_err_sys(EC_LIB_SOCKET, + "Can't get %s receive buffer size: %s", nl->name, + safe_strerror(errno)); + return -1; + } + + /* Try force option (linux >= 2.6.14) and fall back to normal set */ + frr_with_privs(&zserv_privs) { + ret = setsockopt(nl->sock, SOL_SOCKET, SO_RCVBUFFORCE, + &rcvbufsize, sizeof(rcvbufsize)); + } + if (ret < 0) + ret = setsockopt(nl->sock, SOL_SOCKET, SO_RCVBUF, &rcvbufsize, + sizeof(rcvbufsize)); + if (ret < 0) { + flog_err_sys(EC_LIB_SOCKET, + "Can't set %s receive buffer size: %s", nl->name, + safe_strerror(errno)); + return -1; + } + + ret = getsockopt(nl->sock, SOL_SOCKET, SO_RCVBUF, &newsize, &newlen); + if (ret < 0) { + flog_err_sys(EC_LIB_SOCKET, + "Can't get %s receive buffer size: %s", nl->name, + safe_strerror(errno)); + return -1; + } + return 0; +} + +static const char *group2str(uint32_t group) +{ + switch (group) { + case RTNLGRP_TUNNEL: + return "RTNLGRP_TUNNEL"; + default: + return "UNKNOWN"; + } +} + +/* Make socket for Linux netlink interface. */ +static int netlink_socket(struct nlsock *nl, unsigned long groups, + uint32_t ext_groups[], uint8_t ext_group_size, + ns_id_t ns_id) +{ + int ret; + struct sockaddr_nl snl; + int sock; + int namelen; + + frr_with_privs(&zserv_privs) { + sock = ns_socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE, ns_id); + if (sock < 0) { + zlog_err("Can't open %s socket: %s", nl->name, + safe_strerror(errno)); + return -1; + } + + memset(&snl, 0, sizeof(snl)); + snl.nl_family = AF_NETLINK; + snl.nl_groups = groups; + + if (ext_group_size) { + uint8_t i; + + for (i = 0; i < ext_group_size; i++) { +#if defined SOL_NETLINK + ret = setsockopt(sock, SOL_NETLINK, + NETLINK_ADD_MEMBERSHIP, + &ext_groups[i], + sizeof(ext_groups[i])); + if (ret < 0) { + zlog_notice( + "can't setsockopt NETLINK_ADD_MEMBERSHIP for group %s(%u), this linux kernel does not support it: %s(%d)", + group2str(ext_groups[i]), + ext_groups[i], + safe_strerror(errno), errno); + } +#else + zlog_notice( + "Unable to use NETLINK_ADD_MEMBERSHIP via SOL_NETLINK for %s(%u) since the linux kernel does not support the socket option", + group2str(ext_groups[i]), + ext_groups[i]); +#endif + } + } + + /* Bind the socket to the netlink structure for anything. */ + ret = bind(sock, (struct sockaddr *)&snl, sizeof(snl)); + } + + if (ret < 0) { + zlog_err("Can't bind %s socket to group 0x%x: %s", nl->name, + snl.nl_groups, safe_strerror(errno)); + close(sock); + return -1; + } + + /* multiple netlink sockets will have different nl_pid */ + namelen = sizeof(snl); + ret = getsockname(sock, (struct sockaddr *)&snl, (socklen_t *)&namelen); + if (ret < 0 || namelen != sizeof(snl)) { + flog_err_sys(EC_LIB_SOCKET, "Can't get %s socket name: %s", + nl->name, safe_strerror(errno)); + close(sock); + return -1; + } + + nl->snl = snl; + nl->sock = sock; + nl->buflen = NL_RCV_PKT_BUF_SIZE; + nl->buf = XMALLOC(MTYPE_NL_BUF, nl->buflen); + + return ret; +} + +/* + * Dispatch an incoming netlink message; used by the zebra main pthread's + * netlink event reader. + */ +static int netlink_information_fetch(struct nlmsghdr *h, ns_id_t ns_id, + int startup) +{ + /* + * When we handle new message types here + * because we are starting to install them + * then lets check the netlink_install_filter + * and see if we should add the corresponding + * allow through entry there. + * Probably not needed to do but please + * think about it. + */ + switch (h->nlmsg_type) { + case RTM_NEWROUTE: + return netlink_route_change(h, ns_id, startup); + case RTM_DELROUTE: + return netlink_route_change(h, ns_id, startup); + case RTM_NEWLINK: + return netlink_link_change(h, ns_id, startup); + case RTM_DELLINK: + return 0; + case RTM_NEWNEIGH: + case RTM_DELNEIGH: + case RTM_GETNEIGH: + return netlink_neigh_change(h, ns_id); + case RTM_NEWRULE: + return netlink_rule_change(h, ns_id, startup); + case RTM_DELRULE: + return netlink_rule_change(h, ns_id, startup); + case RTM_NEWNEXTHOP: + return netlink_nexthop_change(h, ns_id, startup); + case RTM_DELNEXTHOP: + return netlink_nexthop_change(h, ns_id, startup); + case RTM_NEWQDISC: + case RTM_DELQDISC: + return netlink_qdisc_change(h, ns_id, startup); + case RTM_NEWTCLASS: + case RTM_DELTCLASS: + return netlink_tclass_change(h, ns_id, startup); + case RTM_NEWTFILTER: + case RTM_DELTFILTER: + return netlink_tfilter_change(h, ns_id, startup); + case RTM_NEWVLAN: + return netlink_vlan_change(h, ns_id, startup); + case RTM_DELVLAN: + return netlink_vlan_change(h, ns_id, startup); + + /* Messages we may receive, but ignore */ + case RTM_NEWCHAIN: + case RTM_DELCHAIN: + case RTM_GETCHAIN: + return 0; + + /* Messages handled in the dplane thread */ + case RTM_NEWADDR: + case RTM_DELADDR: + case RTM_NEWNETCONF: + case RTM_DELNETCONF: + case RTM_NEWTUNNEL: + case RTM_DELTUNNEL: + case RTM_GETTUNNEL: + return 0; + default: + /* + * If we have received this message then + * we have made a mistake during development + * and we need to write some code to handle + * this message type or not ask for + * it to be sent up to us + */ + flog_err(EC_ZEBRA_UNKNOWN_NLMSG, + "Unknown netlink nlmsg_type %s(%d) vrf %u", + nl_msg_type_to_str(h->nlmsg_type), h->nlmsg_type, + ns_id); + break; + } + return 0; +} + +/* + * Dispatch an incoming netlink message; used by the dataplane pthread's + * netlink event reader code. + */ +static int dplane_netlink_information_fetch(struct nlmsghdr *h, ns_id_t ns_id, + int startup) +{ + /* + * Dispatch the incoming messages that the dplane pthread handles + */ + switch (h->nlmsg_type) { + case RTM_NEWADDR: + case RTM_DELADDR: + return netlink_interface_addr_dplane(h, ns_id, startup); + + case RTM_NEWNETCONF: + case RTM_DELNETCONF: + return netlink_netconf_change(h, ns_id, startup); + + /* TODO -- other messages for the dplane socket and pthread */ + + case RTM_NEWLINK: + case RTM_DELLINK: + return netlink_link_change(h, ns_id, startup); + + default: + break; + } + + return 0; +} + +static void kernel_read(struct event *thread) +{ + struct zebra_ns *zns = (struct zebra_ns *)EVENT_ARG(thread); + struct zebra_dplane_info dp_info; + + /* Capture key info from ns struct */ + zebra_dplane_info_from_zns(&dp_info, zns, false); + + netlink_parse_info(netlink_information_fetch, &zns->netlink, &dp_info, + 5, false); + + event_add_read(zrouter.master, kernel_read, zns, zns->netlink.sock, + &zns->t_netlink); +} + +/* + * Called by the dplane pthread to read incoming OS messages and dispatch them. + */ +int kernel_dplane_read(struct zebra_dplane_info *info) +{ + struct nlsock *nl = kernel_netlink_nlsock_lookup(info->sock); + + netlink_parse_info(dplane_netlink_information_fetch, nl, info, 5, + false); + + return 0; +} + +/* + * Filter out messages from self that occur on listener socket, + * caused by our actions on the command socket(s) + * + * When we add new Netlink message types we probably + * do not need to add them here as that we are filtering + * on the routes we actually care to receive( which is rarer + * then the normal course of operations). We are intentionally + * allowing some messages from ourselves through + * ( I'm looking at you Interface based netlink messages ) + * so that we only have to write one way to handle incoming + * address add/delete and xxxNETCONF changes. + */ +static void netlink_install_filter(int sock, uint32_t pid, uint32_t dplane_pid) +{ + /* + * BPF_JUMP instructions and where you jump to are based upon + * 0 as being the next statement. So count from 0. Writing + * this down because every time I look at this I have to + * re-remember it. + */ + struct sock_filter filter[] = { + /* + * Logic: + * if (nlmsg_pid == pid || + * nlmsg_pid == dplane_pid) { + * if (the incoming nlmsg_type == + * RTM_NEWADDR || RTM_DELADDR || RTM_NEWNETCONF || + * RTM_DELNETCONF) + * keep this message + * else + * skip this message + * } else + * keep this netlink message + */ + /* + * 0: Load the nlmsg_pid into the BPF register + */ + BPF_STMT(BPF_LD | BPF_ABS | BPF_W, + offsetof(struct nlmsghdr, nlmsg_pid)), + /* + * 1: Compare to pid + */ + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htonl(pid), 1, 0), + /* + * 2: Compare to dplane pid + */ + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htonl(dplane_pid), 0, 6), + /* + * 3: Load the nlmsg_type into BPF register + */ + BPF_STMT(BPF_LD | BPF_ABS | BPF_H, + offsetof(struct nlmsghdr, nlmsg_type)), + /* + * 4: Compare to RTM_NEWADDR + */ + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htons(RTM_NEWADDR), 4, 0), + /* + * 5: Compare to RTM_DELADDR + */ + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htons(RTM_DELADDR), 3, 0), + /* + * 6: Compare to RTM_NEWNETCONF + */ + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htons(RTM_NEWNETCONF), 2, + 0), + /* + * 7: Compare to RTM_DELNETCONF + */ + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htons(RTM_DELNETCONF), 1, + 0), + /* + * 8: This is the end state of we want to skip the + * message + */ + BPF_STMT(BPF_RET | BPF_K, 0), + /* 9: This is the end state of we want to keep + * the message + */ + BPF_STMT(BPF_RET | BPF_K, 0xffff), + }; + + struct sock_fprog prog = { + .len = array_size(filter), .filter = filter, + }; + + if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER, &prog, sizeof(prog)) + < 0) + flog_err_sys(EC_LIB_SOCKET, "Can't install socket filter: %s", + safe_strerror(errno)); +} + +void netlink_parse_rtattr_flags(struct rtattr **tb, int max, struct rtattr *rta, + int len, unsigned short flags) +{ + unsigned short type; + + memset(tb, 0, sizeof(struct rtattr *) * (max + 1)); + while (RTA_OK(rta, len)) { + type = rta->rta_type & ~flags; + if ((type <= max) && (!tb[type])) + tb[type] = rta; + rta = RTA_NEXT(rta, len); + } +} + +void netlink_parse_rtattr(struct rtattr **tb, int max, struct rtattr *rta, + int len) +{ + memset(tb, 0, sizeof(struct rtattr *) * (max + 1)); + while (RTA_OK(rta, len)) { + if (rta->rta_type <= max) + tb[rta->rta_type] = rta; + rta = RTA_NEXT(rta, len); + } +} + +/** + * netlink_parse_rtattr_nested() - Parses a nested route attribute + * @tb: Pointer to array for storing rtattr in. + * @max: Max number to store. + * @rta: Pointer to rtattr to look for nested items in. + */ +void netlink_parse_rtattr_nested(struct rtattr **tb, int max, + struct rtattr *rta) +{ + netlink_parse_rtattr(tb, max, RTA_DATA(rta), RTA_PAYLOAD(rta)); +} + +bool nl_addraw_l(struct nlmsghdr *n, unsigned int maxlen, const void *data, + unsigned int len) +{ + if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) { + zlog_err("ERROR message exceeded bound of %d", maxlen); + return false; + } + + memcpy(NLMSG_TAIL(n), data, len); + memset((uint8_t *)NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len); + n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len); + + return true; +} + +bool nl_attr_put(struct nlmsghdr *n, unsigned int maxlen, int type, + const void *data, unsigned int alen) +{ + int len; + struct rtattr *rta; + + len = RTA_LENGTH(alen); + + if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) + return false; + + rta = (struct rtattr *)(((char *)n) + NLMSG_ALIGN(n->nlmsg_len)); + rta->rta_type = type; + rta->rta_len = len; + + if (data) + memcpy(RTA_DATA(rta), data, alen); + else + assert(alen == 0); + + n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len); + + return true; +} + +bool nl_attr_put8(struct nlmsghdr *n, unsigned int maxlen, int type, + uint8_t data) +{ + return nl_attr_put(n, maxlen, type, &data, sizeof(uint8_t)); +} + +bool nl_attr_put16(struct nlmsghdr *n, unsigned int maxlen, int type, + uint16_t data) +{ + return nl_attr_put(n, maxlen, type, &data, sizeof(uint16_t)); +} + +bool nl_attr_put32(struct nlmsghdr *n, unsigned int maxlen, int type, + uint32_t data) +{ + return nl_attr_put(n, maxlen, type, &data, sizeof(uint32_t)); +} + +bool nl_attr_put64(struct nlmsghdr *n, unsigned int maxlen, int type, + uint64_t data) +{ + return nl_attr_put(n, maxlen, type, &data, sizeof(uint64_t)); +} + +struct rtattr *nl_attr_nest(struct nlmsghdr *n, unsigned int maxlen, int type) +{ + struct rtattr *nest = NLMSG_TAIL(n); + + if (!nl_attr_put(n, maxlen, type, NULL, 0)) + return NULL; + + nest->rta_type |= NLA_F_NESTED; + return nest; +} + +int nl_attr_nest_end(struct nlmsghdr *n, struct rtattr *nest) +{ + nest->rta_len = (uint8_t *)NLMSG_TAIL(n) - (uint8_t *)nest; + return n->nlmsg_len; +} + +struct rtnexthop *nl_attr_rtnh(struct nlmsghdr *n, unsigned int maxlen) +{ + struct rtnexthop *rtnh = (struct rtnexthop *)NLMSG_TAIL(n); + + if (NLMSG_ALIGN(n->nlmsg_len) + RTNH_ALIGN(sizeof(struct rtnexthop)) + > maxlen) + return NULL; + + memset(rtnh, 0, sizeof(struct rtnexthop)); + n->nlmsg_len = + NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(sizeof(struct rtnexthop)); + + return rtnh; +} + +void nl_attr_rtnh_end(struct nlmsghdr *n, struct rtnexthop *rtnh) +{ + rtnh->rtnh_len = (uint8_t *)NLMSG_TAIL(n) - (uint8_t *)rtnh; +} + +const char *nl_msg_type_to_str(uint16_t msg_type) +{ + return lookup_msg(nlmsg_str, msg_type, ""); +} + +const char *nl_rtproto_to_str(uint8_t rtproto) +{ + return lookup_msg(rtproto_str, rtproto, ""); +} + +const char *nl_family_to_str(uint8_t family) +{ + return lookup_msg(family_str, family, ""); +} + +const char *nl_rttype_to_str(uint8_t rttype) +{ + return lookup_msg(rttype_str, rttype, ""); +} + +#define NLA_OK(nla, len) \ + ((len) >= (int)sizeof(struct nlattr) \ + && (nla)->nla_len >= sizeof(struct nlattr) \ + && (nla)->nla_len <= (len)) +#define NLA_NEXT(nla, attrlen) \ + ((attrlen) -= NLA_ALIGN((nla)->nla_len), \ + (struct nlattr *)(((char *)(nla)) + NLA_ALIGN((nla)->nla_len))) +#define NLA_LENGTH(len) (NLA_ALIGN(sizeof(struct nlattr)) + (len)) +#define NLA_DATA(nla) ((struct nlattr *)(((char *)(nla)) + NLA_LENGTH(0))) + +#define ERR_NLA(err, inner_len) \ + ((struct nlattr *)(((char *)(err)) \ + + NLMSG_ALIGN(sizeof(struct nlmsgerr)) \ + + NLMSG_ALIGN((inner_len)))) + +static void netlink_parse_nlattr(struct nlattr **tb, int max, + struct nlattr *nla, int len) +{ + while (NLA_OK(nla, len)) { + if (nla->nla_type <= max) + tb[nla->nla_type] = nla; + nla = NLA_NEXT(nla, len); + } +} + +static void netlink_parse_extended_ack(struct nlmsghdr *h) +{ + struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {}; + const struct nlmsgerr *err = (const struct nlmsgerr *)NLMSG_DATA(h); + const struct nlmsghdr *err_nlh = NULL; + /* Length not including nlmsghdr */ + uint32_t len = 0; + /* Inner error netlink message length */ + uint32_t inner_len = 0; + const char *msg = NULL; + uint32_t off = 0; + + if (!(h->nlmsg_flags & NLM_F_CAPPED)) + inner_len = (uint32_t)NLMSG_PAYLOAD(&err->msg, 0); + + len = (uint32_t)(NLMSG_PAYLOAD(h, sizeof(struct nlmsgerr)) - inner_len); + + netlink_parse_nlattr(tb, NLMSGERR_ATTR_MAX, ERR_NLA(err, inner_len), + len); + + if (tb[NLMSGERR_ATTR_MSG]) + msg = (const char *)NLA_DATA(tb[NLMSGERR_ATTR_MSG]); + + if (tb[NLMSGERR_ATTR_OFFS]) { + off = *(uint32_t *)NLA_DATA(tb[NLMSGERR_ATTR_OFFS]); + + if (off > h->nlmsg_len) { + zlog_err("Invalid offset for NLMSGERR_ATTR_OFFS"); + } else if (!(h->nlmsg_flags & NLM_F_CAPPED)) { + /* + * Header of failed message + * we are not doing anything currently with it + * but noticing it for later. + */ + err_nlh = &err->msg; + zlog_debug("%s: Received %s extended Ack", __func__, + nl_msg_type_to_str(err_nlh->nlmsg_type)); + } + } + + if (msg && *msg != '\0') { + bool is_err = !!err->error; + + if (is_err) + zlog_err("Extended Error: %s", msg); + else + flog_warn(EC_ZEBRA_NETLINK_EXTENDED_WARNING, + "Extended Warning: %s", msg); + } +} + +/* + * netlink_send_msg - send a netlink message of a certain size. + * + * Returns -1 on error. Otherwise, it returns the number of bytes sent. + */ +static ssize_t netlink_send_msg(const struct nlsock *nl, void *buf, + size_t buflen) +{ + struct sockaddr_nl snl = {}; + struct iovec iov = {}; + struct msghdr msg = {}; + ssize_t status; + int save_errno = 0; + + iov.iov_base = buf; + iov.iov_len = buflen; + msg.msg_name = &snl; + msg.msg_namelen = sizeof(snl); + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + + snl.nl_family = AF_NETLINK; + + /* Send message to netlink interface. */ + frr_with_privs(&zserv_privs) { + status = sendmsg(nl->sock, &msg, 0); + save_errno = errno; + } + + if (IS_ZEBRA_DEBUG_KERNEL_MSGDUMP_SEND) { + zlog_debug("%s: >> netlink message dump [sent]", __func__); +#ifdef NETLINK_DEBUG + nl_dump(buf, buflen); +#else + zlog_hexdump(buf, buflen); +#endif /* NETLINK_DEBUG */ + } + + if (status == -1) { + flog_err_sys(EC_LIB_SOCKET, "%s error: %s", __func__, + safe_strerror(save_errno)); + return -1; + } + + return status; +} + +/* + * netlink_recv_msg - receive a netlink message. + * + * Returns -1 on error, 0 if read would block or the number of bytes received. + */ +static int netlink_recv_msg(struct nlsock *nl, struct msghdr *msg) +{ + struct iovec iov; + int status; + + iov.iov_base = nl->buf; + iov.iov_len = nl->buflen; + msg->msg_iov = &iov; + msg->msg_iovlen = 1; + + do { + int bytes; + + bytes = recv(nl->sock, NULL, 0, MSG_PEEK | MSG_TRUNC); + + if (bytes >= 0 && (size_t)bytes > nl->buflen) { + nl->buf = XREALLOC(MTYPE_NL_BUF, nl->buf, bytes); + nl->buflen = bytes; + iov.iov_base = nl->buf; + iov.iov_len = nl->buflen; + } + + status = recvmsg(nl->sock, msg, 0); + } while (status == -1 && errno == EINTR); + + if (status == -1) { + if (errno == EWOULDBLOCK || errno == EAGAIN) + return 0; + flog_err(EC_ZEBRA_RECVMSG_OVERRUN, "%s recvmsg overrun: %s", + nl->name, safe_strerror(errno)); + /* + * In this case we are screwed. There is no good way to recover + * zebra at this point. + */ + exit(-1); + } + + if (status == 0) { + flog_err_sys(EC_LIB_SOCKET, "%s EOF", nl->name); + return -1; + } + + if (msg->msg_namelen != sizeof(struct sockaddr_nl)) { + flog_err(EC_ZEBRA_NETLINK_LENGTH_ERROR, + "%s sender address length error: length %d", nl->name, + msg->msg_namelen); + return -1; + } + + if (IS_ZEBRA_DEBUG_KERNEL_MSGDUMP_RECV) { + zlog_debug("%s: << netlink message dump [recv]", __func__); +#ifdef NETLINK_DEBUG + nl_dump(nl->buf, status); +#else + zlog_hexdump(nl->buf, status); +#endif /* NETLINK_DEBUG */ + } + + return status; +} + +/* + * netlink_parse_error - parse a netlink error message + * + * Returns 1 if this message is acknowledgement, 0 if this error should be + * ignored, -1 otherwise. + */ +static int netlink_parse_error(const struct nlsock *nl, struct nlmsghdr *h, + bool is_cmd, bool startup) +{ + struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h); + int errnum = err->error; + int msg_type = err->msg.nlmsg_type; + + if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) { + flog_err(EC_ZEBRA_NETLINK_LENGTH_ERROR, + "%s error: message truncated", nl->name); + return -1; + } + + /* + * Parse the extended information before we actually handle it. At this + * point in time we do not do anything other than report the issue. + */ + if (h->nlmsg_flags & NLM_F_ACK_TLVS) + netlink_parse_extended_ack(h); + + /* If the error field is zero, then this is an ACK. */ + if (err->error == 0) { + if (IS_ZEBRA_DEBUG_KERNEL) { + zlog_debug("%s: %s ACK: type=%s(%u), seq=%u, pid=%u", + __func__, nl->name, + nl_msg_type_to_str(err->msg.nlmsg_type), + err->msg.nlmsg_type, err->msg.nlmsg_seq, + err->msg.nlmsg_pid); + } + + return 1; + } + + /* + * Deal with errors that occur because of races in link handling + * or types are not supported in kernel. + */ + if (is_cmd && + ((msg_type == RTM_DELROUTE && + (-errnum == ENODEV || -errnum == ESRCH)) || + (msg_type == RTM_NEWROUTE && + (-errnum == ENETDOWN || -errnum == EEXIST)) || + ((msg_type == RTM_NEWTUNNEL || msg_type == RTM_DELTUNNEL || + msg_type == RTM_GETTUNNEL) && + (-errnum == EOPNOTSUPP)))) { + if (IS_ZEBRA_DEBUG_KERNEL) + zlog_debug("%s: error: %s type=%s(%u), seq=%u, pid=%u", + nl->name, safe_strerror(-errnum), + nl_msg_type_to_str(msg_type), msg_type, + err->msg.nlmsg_seq, err->msg.nlmsg_pid); + return 0; + } + + /* + * We see RTM_DELNEIGH when shutting down an interface with an IPv4 + * link-local. The kernel should have already deleted the neighbor so + * do not log these as an error. + */ + if (msg_type == RTM_DELNEIGH + || (is_cmd && msg_type == RTM_NEWROUTE + && (-errnum == ESRCH || -errnum == ENETUNREACH))) { + /* + * This is known to happen in some situations, don't log as + * error. + */ + if (IS_ZEBRA_DEBUG_KERNEL) + zlog_debug("%s error: %s, type=%s(%u), seq=%u, pid=%u", + nl->name, safe_strerror(-errnum), + nl_msg_type_to_str(msg_type), msg_type, + err->msg.nlmsg_seq, err->msg.nlmsg_pid); + } else { + if ((msg_type != RTM_GETNEXTHOP && msg_type != RTM_GETVLAN) || + !startup) + flog_err(EC_ZEBRA_UNEXPECTED_MESSAGE, + "%s error: %s, type=%s(%u), seq=%u, pid=%u", + nl->name, safe_strerror(-errnum), + nl_msg_type_to_str(msg_type), msg_type, + err->msg.nlmsg_seq, err->msg.nlmsg_pid); + } + + return -1; +} + +/* + * netlink_parse_info + * + * Receive message from netlink interface and pass those information + * to the given function. + * + * filter -> Function to call to read the results + * nl -> netlink socket information + * zns -> The zebra namespace data + * count -> How many we should read in, 0 means as much as possible + * startup -> Are we reading in under startup conditions? passed to + * the filter. + */ +int netlink_parse_info(int (*filter)(struct nlmsghdr *, ns_id_t, int), + struct nlsock *nl, const struct zebra_dplane_info *zns, + int count, bool startup) +{ + int status; + int ret = 0; + int error; + int read_in = 0; + + while (1) { + struct sockaddr_nl snl; + struct msghdr msg = {.msg_name = (void *)&snl, + .msg_namelen = sizeof(snl)}; + struct nlmsghdr *h; + + if (count && read_in >= count) + return 0; + + status = netlink_recv_msg(nl, &msg); + if (status == -1) + return -1; + else if (status == 0) + break; + + read_in++; + for (h = (struct nlmsghdr *)nl->buf; + (status >= 0 && NLMSG_OK(h, (unsigned int)status)); + h = NLMSG_NEXT(h, status)) { + /* Finish of reading. */ + if (h->nlmsg_type == NLMSG_DONE) + return ret; + + /* Error handling. */ + if (h->nlmsg_type == NLMSG_ERROR) { + int err = netlink_parse_error( + nl, h, zns->is_cmd, startup); + + if (err == 1) { + if (!(h->nlmsg_flags & NLM_F_MULTI)) + return 0; + continue; + } else + return err; + } + + /* + * What is the right thing to do? The kernel + * is telling us that the dump request was interrupted + * and we more than likely are out of luck and have + * missed data from the kernel. At this point in time + * lets just note that this is happening. + */ + if (h->nlmsg_flags & NLM_F_DUMP_INTR) + flog_err( + EC_ZEBRA_NETLINK_BAD_SEQUENCE, + "netlink recvmsg: The Dump request was interrupted"); + + /* OK we got netlink message. */ + if (IS_ZEBRA_DEBUG_KERNEL) + zlog_debug( + "%s: %s type %s(%u), len=%d, seq=%u, pid=%u", + __func__, nl->name, + nl_msg_type_to_str(h->nlmsg_type), + h->nlmsg_type, h->nlmsg_len, + h->nlmsg_seq, h->nlmsg_pid); + + /* + * Ignore messages that maybe sent from + * other actors besides the kernel + */ + if (snl.nl_pid != 0) { + zlog_debug("Ignoring message from pid %u", + snl.nl_pid); + continue; + } + + error = (*filter)(h, zns->ns_id, startup); + if (error < 0) { + zlog_debug("%s filter function error", + nl->name); + ret = error; + } + } + + /* After error care. */ + if (msg.msg_flags & MSG_TRUNC) { + flog_err(EC_ZEBRA_NETLINK_LENGTH_ERROR, + "%s error: message truncated", nl->name); + continue; + } + if (status) { + flog_err(EC_ZEBRA_NETLINK_LENGTH_ERROR, + "%s error: data remnant size %d", nl->name, + status); + return -1; + } + } + return ret; +} + +/* + * netlink_talk_info + * + * sendmsg() to netlink socket then recvmsg(). + * Calls netlink_parse_info to parse returned data + * + * filter -> The filter to read final results from kernel + * nlmsghdr -> The data to send to the kernel + * dp_info -> The dataplane and netlink socket information + * startup -> Are we reading in under startup conditions + * This is passed through eventually to filter. + */ +static int netlink_talk_info(int (*filter)(struct nlmsghdr *, ns_id_t, + int startup), + struct nlmsghdr *n, + struct zebra_dplane_info *dp_info, bool startup) +{ + struct nlsock *nl; + + nl = kernel_netlink_nlsock_lookup(dp_info->sock); + n->nlmsg_seq = dp_info->seq; + n->nlmsg_pid = nl->snl.nl_pid; + + if (IS_ZEBRA_DEBUG_KERNEL) + zlog_debug( + "netlink_talk: %s type %s(%u), len=%d seq=%u flags 0x%x", + nl->name, nl_msg_type_to_str(n->nlmsg_type), + n->nlmsg_type, n->nlmsg_len, n->nlmsg_seq, + n->nlmsg_flags); + + if (netlink_send_msg(nl, n, n->nlmsg_len) == -1) + return -1; + + /* + * Get reply from netlink socket. + * The reply should either be an acknowlegement or an error. + */ + return netlink_parse_info(filter, nl, dp_info, 0, startup); +} + +/* + * Synchronous version of netlink_talk_info. Converts args to suit the + * common version, which is suitable for both sync and async use. + */ +int netlink_talk(int (*filter)(struct nlmsghdr *, ns_id_t, int startup), + struct nlmsghdr *n, struct nlsock *nl, struct zebra_ns *zns, + bool startup) +{ + struct zebra_dplane_info dp_info; + + /* Increment sequence number before capturing snapshot of ns socket + * info. + */ + nl->seq++; + + /* Capture info in intermediate info struct */ + zebra_dplane_info_from_zns(&dp_info, zns, (nl == &(zns->netlink_cmd))); + + return netlink_talk_info(filter, n, &dp_info, startup); +} + +/* Issue request message to kernel via netlink socket. GET messages + * are issued through this interface. + */ +int netlink_request(struct nlsock *nl, void *req) +{ + struct nlmsghdr *n = (struct nlmsghdr *)req; + + /* Check netlink socket. */ + if (nl->sock < 0) { + flog_err_sys(EC_LIB_SOCKET, "%s socket isn't active.", + nl->name); + return -1; + } + + /* Fill common fields for all requests. */ + n->nlmsg_pid = nl->snl.nl_pid; + n->nlmsg_seq = ++nl->seq; + + if (netlink_send_msg(nl, req, n->nlmsg_len) == -1) + return -1; + + return 0; +} + +static int nl_batch_read_resp(struct nl_batch *bth, struct nlsock *nl) +{ + struct nlmsghdr *h; + struct sockaddr_nl snl; + struct msghdr msg = {}; + int status, seq; + struct zebra_dplane_ctx *ctx; + bool ignore_msg; + + msg.msg_name = (void *)&snl; + msg.msg_namelen = sizeof(snl); + + /* + * The responses are not batched, so we need to read and process one + * message at a time. + */ + while (true) { + status = netlink_recv_msg(nl, &msg); + /* + * status == -1 is a full on failure somewhere + * since we don't know where the problem happened + * we must mark all as failed + * + * Else we mark everything as worked + * + */ + if (status == -1 || status == 0) { + while ((ctx = dplane_ctx_dequeue(&(bth->ctx_list))) != + NULL) { + if (status == -1) + dplane_ctx_set_status( + ctx, + ZEBRA_DPLANE_REQUEST_FAILURE); + dplane_ctx_enqueue_tail(bth->ctx_out_q, ctx); + } + return status; + } + + h = (struct nlmsghdr *)nl->buf; + ignore_msg = false; + seq = h->nlmsg_seq; + /* + * Find the corresponding context object. Received responses are + * in the same order as requests we sent, so we can simply + * iterate over the context list and match responses with + * requests at same time. + */ + while (true) { + ctx = dplane_ctx_get_head(&(bth->ctx_list)); + if (ctx == NULL) { + /* + * This is a situation where we have gotten + * into a bad spot. We need to know that + * this happens( does it? ) + */ + zlog_err( + "%s:WARNING Received netlink Response for an error and no Contexts to associate with it", + __func__); + break; + } + + /* + * 'update' context objects take two consecutive + * sequence numbers. + */ + if (dplane_ctx_is_update(ctx) && + dplane_ctx_get_ns(ctx)->seq + 1 == seq) { + /* + * This is the situation where we get a response + * to a message that should be ignored. + */ + ignore_msg = true; + break; + } + + ctx = dplane_ctx_dequeue(&(bth->ctx_list)); + dplane_ctx_enqueue_tail(bth->ctx_out_q, ctx); + + /* We have found corresponding context object. */ + if (dplane_ctx_get_ns(ctx)->seq == seq) + break; + + if (dplane_ctx_get_ns(ctx)->seq > seq) + zlog_warn( + "%s:WARNING Received %u is less than any context on the queue ctx->seq %u", + __func__, seq, + dplane_ctx_get_ns(ctx)->seq); + } + + if (ignore_msg) { + /* + * If we ignore the message due to an update + * above we should still fricking decode the + * message for our operator to understand + * what is going on + */ + int err = netlink_parse_error(nl, h, bth->zns->is_cmd, + false); + + zlog_debug("%s: netlink error message seq=%d %d", + __func__, h->nlmsg_seq, err); + continue; + } + + /* + * We received a message with the sequence number that isn't + * associated with any dplane context object. + */ + if (ctx == NULL) { + if (IS_ZEBRA_DEBUG_KERNEL) + zlog_debug( + "%s: skipping unassociated response, seq number %d NS %u", + __func__, h->nlmsg_seq, + bth->zns->ns_id); + continue; + } + + if (h->nlmsg_type == NLMSG_ERROR) { + int err = netlink_parse_error(nl, h, bth->zns->is_cmd, + false); + + if (err == -1) + dplane_ctx_set_status( + ctx, ZEBRA_DPLANE_REQUEST_FAILURE); + + if (IS_ZEBRA_DEBUG_KERNEL) + zlog_debug("%s: netlink error message seq=%d ", + __func__, h->nlmsg_seq); + continue; + } + + /* + * If we get here then we did not receive neither the ack nor + * the error and instead received some other message in an + * unexpected way. + */ + if (IS_ZEBRA_DEBUG_KERNEL) + zlog_debug("%s: ignoring message type 0x%04x(%s) NS %u", + __func__, h->nlmsg_type, + nl_msg_type_to_str(h->nlmsg_type), + bth->zns->ns_id); + } + + return 0; +} + +static void nl_batch_reset(struct nl_batch *bth) +{ + bth->buf_head = bth->buf; + bth->curlen = 0; + bth->msgcnt = 0; + bth->zns = NULL; + + dplane_ctx_q_init(&(bth->ctx_list)); +} + +static void nl_batch_init(struct nl_batch *bth, + struct dplane_ctx_list_head *ctx_out_q) +{ + /* + * If the size of the buffer has changed, free and then allocate a new + * one. + */ + size_t bufsize = + atomic_load_explicit(&nl_batch_bufsize, memory_order_relaxed); + if (bufsize != nl_batch_tx_bufsize) { + if (nl_batch_tx_buf) + XFREE(MTYPE_NL_BUF, nl_batch_tx_buf); + + nl_batch_tx_buf = XCALLOC(MTYPE_NL_BUF, bufsize); + nl_batch_tx_bufsize = bufsize; + } + + bth->buf = nl_batch_tx_buf; + bth->bufsiz = bufsize; + bth->limit = atomic_load_explicit(&nl_batch_send_threshold, + memory_order_relaxed); + + bth->ctx_out_q = ctx_out_q; + + nl_batch_reset(bth); +} + +static void nl_batch_send(struct nl_batch *bth) +{ + struct zebra_dplane_ctx *ctx; + bool err = false; + + if (bth->curlen != 0 && bth->zns != NULL) { + struct nlsock *nl = + kernel_netlink_nlsock_lookup(bth->zns->sock); + + if (IS_ZEBRA_DEBUG_KERNEL) + zlog_debug("%s: %s, batch size=%zu, msg cnt=%zu", + __func__, nl->name, bth->curlen, + bth->msgcnt); + + if (netlink_send_msg(nl, bth->buf, bth->curlen) == -1) + err = true; + + if (!err) { + if (nl_batch_read_resp(bth, nl) == -1) + err = true; + } + } + + /* Move remaining contexts to the outbound queue. */ + while (true) { + ctx = dplane_ctx_dequeue(&(bth->ctx_list)); + if (ctx == NULL) + break; + + if (err) + dplane_ctx_set_status(ctx, + ZEBRA_DPLANE_REQUEST_FAILURE); + + dplane_ctx_enqueue_tail(bth->ctx_out_q, ctx); + } + + nl_batch_reset(bth); +} + +enum netlink_msg_status netlink_batch_add_msg( + struct nl_batch *bth, struct zebra_dplane_ctx *ctx, + ssize_t (*msg_encoder)(struct zebra_dplane_ctx *, void *, size_t), + bool ignore_res) +{ + int seq; + ssize_t size; + struct nlmsghdr *msgh; + struct nlsock *nl; + + size = (*msg_encoder)(ctx, bth->buf_head, bth->bufsiz - bth->curlen); + + /* + * If there was an error while encoding the message (other than buffer + * overflow) then return an error. + */ + if (size < 0) + return FRR_NETLINK_ERROR; + + /* + * If the message doesn't fit entirely in the buffer then send the batch + * and retry. + */ + if (size == 0) { + nl_batch_send(bth); + size = (*msg_encoder)(ctx, bth->buf_head, + bth->bufsiz - bth->curlen); + /* + * If the message doesn't fit in the empty buffer then just + * return an error. + */ + if (size <= 0) + return FRR_NETLINK_ERROR; + } + + seq = dplane_ctx_get_ns(ctx)->seq; + nl = kernel_netlink_nlsock_lookup(dplane_ctx_get_ns_sock(ctx)); + + if (ignore_res) + seq++; + + msgh = (struct nlmsghdr *)bth->buf_head; + msgh->nlmsg_seq = seq; + msgh->nlmsg_pid = nl->snl.nl_pid; + + bth->zns = dplane_ctx_get_ns(ctx); + bth->buf_head = ((char *)bth->buf_head) + size; + bth->curlen += size; + bth->msgcnt++; + + return FRR_NETLINK_QUEUED; +} + +static enum netlink_msg_status nl_put_msg(struct nl_batch *bth, + struct zebra_dplane_ctx *ctx) +{ + if (dplane_ctx_is_skip_kernel(ctx)) + return FRR_NETLINK_SUCCESS; + + switch (dplane_ctx_get_op(ctx)) { + + case DPLANE_OP_ROUTE_INSTALL: + case DPLANE_OP_ROUTE_UPDATE: + case DPLANE_OP_ROUTE_DELETE: + return netlink_put_route_update_msg(bth, ctx); + + case DPLANE_OP_NH_INSTALL: + case DPLANE_OP_NH_UPDATE: + case DPLANE_OP_NH_DELETE: + return netlink_put_nexthop_update_msg(bth, ctx); + + case DPLANE_OP_LSP_INSTALL: + case DPLANE_OP_LSP_UPDATE: + case DPLANE_OP_LSP_DELETE: + return netlink_put_lsp_update_msg(bth, ctx); + + case DPLANE_OP_PW_INSTALL: + case DPLANE_OP_PW_UNINSTALL: + return netlink_put_pw_update_msg(bth, ctx); + + case DPLANE_OP_ADDR_INSTALL: + case DPLANE_OP_ADDR_UNINSTALL: + return netlink_put_address_update_msg(bth, ctx); + + case DPLANE_OP_MAC_INSTALL: + case DPLANE_OP_MAC_DELETE: + return netlink_put_mac_update_msg(bth, ctx); + + case DPLANE_OP_NEIGH_INSTALL: + case DPLANE_OP_NEIGH_UPDATE: + case DPLANE_OP_NEIGH_DELETE: + case DPLANE_OP_VTEP_ADD: + case DPLANE_OP_VTEP_DELETE: + case DPLANE_OP_NEIGH_DISCOVER: + case DPLANE_OP_NEIGH_IP_INSTALL: + case DPLANE_OP_NEIGH_IP_DELETE: + case DPLANE_OP_NEIGH_TABLE_UPDATE: + return netlink_put_neigh_update_msg(bth, ctx); + + case DPLANE_OP_RULE_ADD: + case DPLANE_OP_RULE_DELETE: + case DPLANE_OP_RULE_UPDATE: + return netlink_put_rule_update_msg(bth, ctx); + + case DPLANE_OP_SYS_ROUTE_ADD: + case DPLANE_OP_SYS_ROUTE_DELETE: + case DPLANE_OP_ROUTE_NOTIFY: + case DPLANE_OP_LSP_NOTIFY: + case DPLANE_OP_BR_PORT_UPDATE: + return FRR_NETLINK_SUCCESS; + + case DPLANE_OP_IPTABLE_ADD: + case DPLANE_OP_IPTABLE_DELETE: + case DPLANE_OP_IPSET_ADD: + case DPLANE_OP_IPSET_DELETE: + case DPLANE_OP_IPSET_ENTRY_ADD: + case DPLANE_OP_IPSET_ENTRY_DELETE: + case DPLANE_OP_STARTUP_STAGE: + return FRR_NETLINK_ERROR; + + case DPLANE_OP_GRE_SET: + return netlink_put_gre_set_msg(bth, ctx); + + case DPLANE_OP_INTF_ADDR_ADD: + case DPLANE_OP_INTF_ADDR_DEL: + case DPLANE_OP_NONE: + return FRR_NETLINK_ERROR; + + case DPLANE_OP_INTF_NETCONFIG: + return netlink_put_intf_netconfig(bth, ctx); + + case DPLANE_OP_INTF_INSTALL: + case DPLANE_OP_INTF_UPDATE: + case DPLANE_OP_INTF_DELETE: + return netlink_put_intf_update_msg(bth, ctx); + + case DPLANE_OP_TC_QDISC_INSTALL: + case DPLANE_OP_TC_QDISC_UNINSTALL: + return netlink_put_tc_qdisc_update_msg(bth, ctx); + case DPLANE_OP_TC_CLASS_ADD: + case DPLANE_OP_TC_CLASS_DELETE: + case DPLANE_OP_TC_CLASS_UPDATE: + return netlink_put_tc_class_update_msg(bth, ctx); + case DPLANE_OP_TC_FILTER_ADD: + case DPLANE_OP_TC_FILTER_DELETE: + case DPLANE_OP_TC_FILTER_UPDATE: + return netlink_put_tc_filter_update_msg(bth, ctx); + } + + return FRR_NETLINK_ERROR; +} + +void kernel_update_multi(struct dplane_ctx_list_head *ctx_list) +{ + struct nl_batch batch; + struct zebra_dplane_ctx *ctx; + struct dplane_ctx_list_head handled_list; + enum netlink_msg_status res; + + dplane_ctx_q_init(&handled_list); + nl_batch_init(&batch, &handled_list); + + while (true) { + ctx = dplane_ctx_dequeue(ctx_list); + if (ctx == NULL) + break; + + if (batch.zns != NULL + && batch.zns->ns_id != dplane_ctx_get_ns(ctx)->ns_id) + nl_batch_send(&batch); + + /* + * Assume all messages will succeed and then mark only the ones + * that failed. + */ + dplane_ctx_set_status(ctx, ZEBRA_DPLANE_REQUEST_SUCCESS); + + res = nl_put_msg(&batch, ctx); + + dplane_ctx_enqueue_tail(&(batch.ctx_list), ctx); + if (res == FRR_NETLINK_ERROR) + dplane_ctx_set_status(ctx, + ZEBRA_DPLANE_REQUEST_FAILURE); + + if (batch.curlen > batch.limit) + nl_batch_send(&batch); + } + + nl_batch_send(&batch); + + dplane_ctx_q_init(ctx_list); + dplane_ctx_list_append(ctx_list, &handled_list); +} + +struct nlsock *kernel_netlink_nlsock_lookup(int sock) +{ + struct nlsock lookup, *retval; + + lookup.sock = sock; + + NLSOCK_LOCK(); + retval = hash_lookup(nlsock_hash, &lookup); + NLSOCK_UNLOCK(); + + return retval; +} + +/* Insert nlsock entry into hash */ +static void kernel_netlink_nlsock_insert(struct nlsock *nls) +{ + NLSOCK_LOCK(); + (void)hash_get(nlsock_hash, nls, hash_alloc_intern); + NLSOCK_UNLOCK(); +} + +/* Remove nlsock entry from hash */ +static void kernel_netlink_nlsock_remove(struct nlsock *nls) +{ + NLSOCK_LOCK(); + (void)hash_release(nlsock_hash, nls); + NLSOCK_UNLOCK(); +} + +static uint32_t kernel_netlink_nlsock_key(const void *arg) +{ + const struct nlsock *nl = arg; + + return nl->sock; +} + +static bool kernel_netlink_nlsock_hash_equal(const void *arg1, const void *arg2) +{ + const struct nlsock *nl1 = arg1; + const struct nlsock *nl2 = arg2; + + if (nl1->sock == nl2->sock) + return true; + + return false; +} + +/* Exported interface function. This function simply calls + netlink_socket (). */ +void kernel_init(struct zebra_ns *zns) +{ + uint32_t groups, dplane_groups, ext_groups; +#if defined SOL_NETLINK + int one, ret, grp; +#endif + + /* + * Initialize netlink sockets + * + * If RTMGRP_XXX exists use that, but at some point + * I think the kernel developers realized that + * keeping track of all the different values would + * lead to confusion, so we need to convert the + * RTNLGRP_XXX to a bit position for ourself + * + * + * NOTE: If the bit is >= 32, you must use setsockopt(). Those + * groups are added further below after SOL_NETLINK is verified to + * exist. + */ + groups = RTMGRP_IPV4_ROUTE | RTMGRP_IPV6_ROUTE | RTMGRP_IPV4_MROUTE | + RTMGRP_NEIGH | ((uint32_t)1 << (RTNLGRP_IPV4_RULE - 1)) | + ((uint32_t)1 << (RTNLGRP_IPV6_RULE - 1)) | + ((uint32_t)1 << (RTNLGRP_NEXTHOP - 1)) | + ((uint32_t)1 << (RTNLGRP_TC - 1)); + + dplane_groups = (RTMGRP_LINK | + RTMGRP_IPV4_IFADDR | + RTMGRP_IPV6_IFADDR | + ((uint32_t) 1 << (RTNLGRP_IPV4_NETCONF - 1)) | + ((uint32_t) 1 << (RTNLGRP_IPV6_NETCONF - 1)) | + ((uint32_t) 1 << (RTNLGRP_MPLS_NETCONF - 1))); + + /* Use setsockopt for > 31 group */ + ext_groups = RTNLGRP_TUNNEL; + + snprintf(zns->netlink.name, sizeof(zns->netlink.name), + "netlink-listen (NS %u)", zns->ns_id); + zns->netlink.sock = -1; + if (netlink_socket(&zns->netlink, groups, &ext_groups, 1, zns->ns_id) < + 0) { + zlog_err("Failure to create %s socket", + zns->netlink.name); + exit(-1); + } + + kernel_netlink_nlsock_insert(&zns->netlink); + + snprintf(zns->netlink_cmd.name, sizeof(zns->netlink_cmd.name), + "netlink-cmd (NS %u)", zns->ns_id); + zns->netlink_cmd.sock = -1; + if (netlink_socket(&zns->netlink_cmd, 0, 0, 0, zns->ns_id) < 0) { + zlog_err("Failure to create %s socket", + zns->netlink_cmd.name); + exit(-1); + } + + kernel_netlink_nlsock_insert(&zns->netlink_cmd); + + /* Outbound socket for dplane programming of the host OS. */ + snprintf(zns->netlink_dplane_out.name, + sizeof(zns->netlink_dplane_out.name), "netlink-dp (NS %u)", + zns->ns_id); + zns->netlink_dplane_out.sock = -1; + if (netlink_socket(&zns->netlink_dplane_out, 0, 0, 0, zns->ns_id) < 0) { + zlog_err("Failure to create %s socket", + zns->netlink_dplane_out.name); + exit(-1); + } + + kernel_netlink_nlsock_insert(&zns->netlink_dplane_out); + + /* Inbound socket for OS events coming to the dplane. */ + snprintf(zns->netlink_dplane_in.name, + sizeof(zns->netlink_dplane_in.name), "netlink-dp-in (NS %u)", + zns->ns_id); + zns->netlink_dplane_in.sock = -1; + if (netlink_socket(&zns->netlink_dplane_in, dplane_groups, 0, 0, + zns->ns_id) < 0) { + zlog_err("Failure to create %s socket", + zns->netlink_dplane_in.name); + exit(-1); + } + + kernel_netlink_nlsock_insert(&zns->netlink_dplane_in); + + /* + * SOL_NETLINK is not available on all platforms yet + * apparently. It's in bits/socket.h which I am not + * sure that we want to pull into our build system. + */ +#if defined SOL_NETLINK + + /* + * setsockopt multicast group subscriptions that don't fit in nl_groups + */ + grp = RTNLGRP_BRVLAN; + ret = setsockopt(zns->netlink.sock, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, + &grp, sizeof(grp)); + + if (ret < 0) + zlog_notice( + "Registration for RTNLGRP_BRVLAN Membership failed : %d %s", + errno, safe_strerror(errno)); + /* + * Let's tell the kernel that we want to receive extended + * ACKS over our command socket(s) + */ + one = 1; + ret = setsockopt(zns->netlink_cmd.sock, SOL_NETLINK, NETLINK_EXT_ACK, + &one, sizeof(one)); + + if (ret < 0) + zlog_notice("Registration for extended cmd ACK failed : %d %s", + errno, safe_strerror(errno)); + + one = 1; + ret = setsockopt(zns->netlink_dplane_out.sock, SOL_NETLINK, + NETLINK_EXT_ACK, &one, sizeof(one)); + + if (ret < 0) + zlog_notice("Registration for extended dp ACK failed : %d %s", + errno, safe_strerror(errno)); + + /* + * Trim off the payload of the original netlink message in the + * acknowledgment. This option is available since Linux 4.2, so if + * setsockopt fails, ignore the error. + */ + one = 1; + ret = setsockopt(zns->netlink_dplane_out.sock, SOL_NETLINK, + NETLINK_CAP_ACK, &one, sizeof(one)); + if (ret < 0) + zlog_notice( + "Registration for reduced ACK packet size failed, probably running an early kernel"); +#endif + + /* Register kernel socket. */ + if (fcntl(zns->netlink.sock, F_SETFL, O_NONBLOCK) < 0) + flog_err_sys(EC_LIB_SOCKET, "Can't set %s socket flags: %s", + zns->netlink.name, safe_strerror(errno)); + + if (fcntl(zns->netlink_cmd.sock, F_SETFL, O_NONBLOCK) < 0) + zlog_err("Can't set %s socket error: %s(%d)", + zns->netlink_cmd.name, safe_strerror(errno), errno); + + if (fcntl(zns->netlink_dplane_out.sock, F_SETFL, O_NONBLOCK) < 0) + zlog_err("Can't set %s socket error: %s(%d)", + zns->netlink_dplane_out.name, safe_strerror(errno), + errno); + + if (fcntl(zns->netlink_dplane_in.sock, F_SETFL, O_NONBLOCK) < 0) + zlog_err("Can't set %s socket error: %s(%d)", + zns->netlink_dplane_in.name, safe_strerror(errno), + errno); + + /* Set receive buffer size if it's set from command line */ + if (rcvbufsize) { + netlink_recvbuf(&zns->netlink, rcvbufsize); + netlink_recvbuf(&zns->netlink_cmd, rcvbufsize); + netlink_recvbuf(&zns->netlink_dplane_out, rcvbufsize); + netlink_recvbuf(&zns->netlink_dplane_in, rcvbufsize); + } + + /* Set filter for inbound sockets, to exclude events we've generated + * ourselves. + */ + netlink_install_filter(zns->netlink.sock, zns->netlink_cmd.snl.nl_pid, + zns->netlink_dplane_out.snl.nl_pid); + + netlink_install_filter(zns->netlink_dplane_in.sock, + zns->netlink_cmd.snl.nl_pid, + zns->netlink_dplane_out.snl.nl_pid); + + zns->t_netlink = NULL; + + event_add_read(zrouter.master, kernel_read, zns, zns->netlink.sock, + &zns->t_netlink); + + rt_netlink_init(); +} + +/* Helper to clean up an nlsock */ +static void kernel_nlsock_fini(struct nlsock *nls) +{ + if (nls && nls->sock >= 0) { + kernel_netlink_nlsock_remove(nls); + close(nls->sock); + nls->sock = -1; + XFREE(MTYPE_NL_BUF, nls->buf); + nls->buflen = 0; + } +} + +void kernel_terminate(struct zebra_ns *zns, bool complete) +{ + EVENT_OFF(zns->t_netlink); + + kernel_nlsock_fini(&zns->netlink); + + kernel_nlsock_fini(&zns->netlink_cmd); + + kernel_nlsock_fini(&zns->netlink_dplane_in); + + /* During zebra shutdown, we need to leave the dataplane socket + * around until all work is done. + */ + if (complete) + kernel_nlsock_fini(&zns->netlink_dplane_out); +} + +/* + * Global init for platform-/OS-specific things + */ +void kernel_router_init(void) +{ + /* Init nlsock hash and lock */ + pthread_mutex_init(&nlsock_mutex, NULL); + nlsock_hash = hash_create_size(8, kernel_netlink_nlsock_key, + kernel_netlink_nlsock_hash_equal, + "Netlink Socket Hash"); +} + +/* + * Global deinit for platform-/OS-specific things + */ +void kernel_router_terminate(void) +{ + pthread_mutex_destroy(&nlsock_mutex); + + hash_free(nlsock_hash); + nlsock_hash = NULL; +} + +#endif /* HAVE_NETLINK */ |