/* * lib/route/rule.c Routing Rules * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation version 2.1 * of the License. * * Copyright (c) 2003-2010 Thomas Graf */ /** * @ingroup rtnl * @defgroup rule Routing Rules * @brief * @{ */ #include #include #include #include #include #include /** @cond SKIP */ #define RULE_ATTR_FAMILY 0x0001 #define RULE_ATTR_TABLE 0x0002 #define RULE_ATTR_ACTION 0x0004 #define RULE_ATTR_FLAGS 0x0008 #define RULE_ATTR_IIFNAME 0x0010 #define RULE_ATTR_OIFNAME 0x0020 #define RULE_ATTR_PRIO 0x0040 #define RULE_ATTR_MARK 0x0080 #define RULE_ATTR_MASK 0x0100 #define RULE_ATTR_GOTO 0x0200 #define RULE_ATTR_SRC 0x0400 #define RULE_ATTR_DST 0x0800 #define RULE_ATTR_DSFIELD 0x1000 #define RULE_ATTR_FLOW 0x2000 static struct nl_cache_ops rtnl_rule_ops; static struct nl_object_ops rule_obj_ops; /** @endcond */ static void rule_free_data(struct nl_object *c) { struct rtnl_rule *rule = nl_object_priv(c); if (!rule) return; nl_addr_put(rule->r_src); nl_addr_put(rule->r_dst); } static int rule_clone(struct nl_object *_dst, struct nl_object *_src) { struct rtnl_rule *dst = nl_object_priv(_dst); struct rtnl_rule *src = nl_object_priv(_src); if (src->r_src) if (!(dst->r_src = nl_addr_clone(src->r_src))) return -NLE_NOMEM; if (src->r_dst) if (!(dst->r_dst = nl_addr_clone(src->r_dst))) return -NLE_NOMEM; return 0; } static struct nla_policy rule_policy[FRA_MAX+1] = { [FRA_TABLE] = { .type = NLA_U32 }, [FRA_IIFNAME] = { .type = NLA_STRING, .maxlen = IFNAMSIZ }, [FRA_OIFNAME] = { .type = NLA_STRING, .maxlen = IFNAMSIZ }, [FRA_PRIORITY] = { .type = NLA_U32 }, [FRA_FWMARK] = { .type = NLA_U32 }, [FRA_FWMASK] = { .type = NLA_U32 }, [FRA_GOTO] = { .type = NLA_U32 }, [FRA_FLOW] = { .type = NLA_U32 }, }; static int rule_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who, struct nlmsghdr *n, struct nl_parser_param *pp) { struct rtnl_rule *rule; struct fib_rule_hdr *frh; struct nlattr *tb[FRA_MAX+1]; int err = 1, family; rule = rtnl_rule_alloc(); if (!rule) { err = -NLE_NOMEM; goto errout; } rule->ce_msgtype = n->nlmsg_type; frh = nlmsg_data(n); err = nlmsg_parse(n, sizeof(*frh), tb, FRA_MAX, rule_policy); if (err < 0) goto errout; rule->r_family = family = frh->family; rule->r_table = frh->table; rule->r_action = frh->action; rule->r_flags = frh->flags; rule->ce_mask = (RULE_ATTR_FAMILY | RULE_ATTR_TABLE | RULE_ATTR_ACTION | RULE_ATTR_FLAGS); /* ipv4 only */ if (frh->tos) { rule->r_dsfield = frh->tos; rule->ce_mask |= RULE_ATTR_DSFIELD; } if (tb[FRA_TABLE]) { rule->r_table = nla_get_u32(tb[FRA_TABLE]); rule->ce_mask |= RULE_ATTR_TABLE; } if (tb[FRA_IIFNAME]) { nla_strlcpy(rule->r_iifname, tb[FRA_IIFNAME], IFNAMSIZ); rule->ce_mask |= RULE_ATTR_IIFNAME; } if (tb[FRA_OIFNAME]) { nla_strlcpy(rule->r_oifname, tb[FRA_OIFNAME], IFNAMSIZ); rule->ce_mask |= RULE_ATTR_OIFNAME; } if (tb[FRA_PRIORITY]) { rule->r_prio = nla_get_u32(tb[FRA_PRIORITY]); rule->ce_mask |= RULE_ATTR_PRIO; } if (tb[FRA_FWMARK]) { rule->r_mark = nla_get_u32(tb[FRA_FWMARK]); rule->ce_mask |= RULE_ATTR_MARK; } if (tb[FRA_FWMASK]) { rule->r_mask = nla_get_u32(tb[FRA_FWMASK]); rule->ce_mask |= RULE_ATTR_MASK; } if (tb[FRA_GOTO]) { rule->r_goto = nla_get_u32(tb[FRA_GOTO]); rule->ce_mask |= RULE_ATTR_GOTO; } if (tb[FRA_SRC]) { if (!(rule->r_src = nl_addr_alloc_attr(tb[FRA_SRC], family))) goto errout_enomem; nl_addr_set_prefixlen(rule->r_src, frh->src_len); rule->ce_mask |= RULE_ATTR_SRC; } if (tb[FRA_DST]) { if (!(rule->r_dst = nl_addr_alloc_attr(tb[FRA_DST], family))) goto errout_enomem; nl_addr_set_prefixlen(rule->r_dst, frh->dst_len); rule->ce_mask |= RULE_ATTR_DST; } /* ipv4 only */ if (tb[FRA_FLOW]) { rule->r_flow = nla_get_u32(tb[FRA_FLOW]); rule->ce_mask |= RULE_ATTR_FLOW; } err = pp->pp_cb((struct nl_object *) rule, pp); errout: rtnl_rule_put(rule); return err; errout_enomem: err = -NLE_NOMEM; goto errout; } static int rule_request_update(struct nl_cache *c, struct nl_sock *h) { return nl_rtgen_request(h, RTM_GETRULE, AF_UNSPEC, NLM_F_DUMP); } static void rule_dump_line(struct nl_object *o, struct nl_dump_params *p) { struct rtnl_rule *r = (struct rtnl_rule *) o; char buf[128]; nl_dump_line(p, "%8d ", (r->ce_mask & RULE_ATTR_PRIO) ? r->r_prio : 0); nl_dump(p, "%s ", nl_af2str(r->r_family, buf, sizeof(buf))); if (r->ce_mask & RULE_ATTR_SRC) nl_dump(p, "from %s ", nl_addr2str(r->r_src, buf, sizeof(buf))); if (r->ce_mask & RULE_ATTR_DST) nl_dump(p, "to %s ", nl_addr2str(r->r_dst, buf, sizeof(buf))); if (r->ce_mask & RULE_ATTR_DSFIELD) nl_dump(p, "tos %u ", r->r_dsfield); if (r->ce_mask & (RULE_ATTR_MARK | RULE_ATTR_MASK)) nl_dump(p, "mark %#x/%#x", r->r_mark, r->r_mask); if (r->ce_mask & RULE_ATTR_IIFNAME) nl_dump(p, "iif %s ", r->r_iifname); if (r->ce_mask & RULE_ATTR_OIFNAME) nl_dump(p, "oif %s ", r->r_oifname); if (r->ce_mask & RULE_ATTR_TABLE) nl_dump(p, "lookup %s ", rtnl_route_table2str(r->r_table, buf, sizeof(buf))); if (r->ce_mask & RULE_ATTR_FLOW) nl_dump(p, "flow %s ", rtnl_realms2str(r->r_flow, buf, sizeof(buf))); if (r->ce_mask & RULE_ATTR_GOTO) nl_dump(p, "goto %u ", r->r_goto); if (r->ce_mask & RULE_ATTR_ACTION) nl_dump(p, "action %s", nl_rtntype2str(r->r_action, buf, sizeof(buf))); nl_dump(p, "\n"); } static void rule_dump_details(struct nl_object *obj, struct nl_dump_params *p) { rule_dump_line(obj, p); } static void rule_dump_stats(struct nl_object *obj, struct nl_dump_params *p) { rule_dump_details(obj, p); } #define RULE_ATTR_FLAGS 0x0008 static uint64_t rule_compare(struct nl_object *_a, struct nl_object *_b, uint64_t attrs, int flags) { struct rtnl_rule *a = (struct rtnl_rule *) _a; struct rtnl_rule *b = (struct rtnl_rule *) _b; uint64_t diff = 0; #define RULE_DIFF(ATTR, EXPR) ATTR_DIFF(attrs, RULE_ATTR_##ATTR, a, b, EXPR) diff |= RULE_DIFF(FAMILY, a->r_family != b->r_family); diff |= RULE_DIFF(TABLE, a->r_table != b->r_table); diff |= RULE_DIFF(ACTION, a->r_action != b->r_action); diff |= RULE_DIFF(IIFNAME, strcmp(a->r_iifname, b->r_iifname)); diff |= RULE_DIFF(OIFNAME, strcmp(a->r_oifname, b->r_oifname)); diff |= RULE_DIFF(PRIO, a->r_prio != b->r_prio); diff |= RULE_DIFF(MARK, a->r_mark != b->r_mark); diff |= RULE_DIFF(MASK, a->r_mask != b->r_mask); diff |= RULE_DIFF(GOTO, a->r_goto != b->r_goto); diff |= RULE_DIFF(SRC, nl_addr_cmp(a->r_src, b->r_src)); diff |= RULE_DIFF(DST, nl_addr_cmp(a->r_dst, b->r_dst)); diff |= RULE_DIFF(DSFIELD, a->r_dsfield != b->r_dsfield); diff |= RULE_DIFF(FLOW, a->r_flow != b->r_flow); #undef RULE_DIFF return diff; } static const struct trans_tbl rule_attrs[] = { __ADD(RULE_ATTR_FAMILY, family), __ADD(RULE_ATTR_TABLE, table), __ADD(RULE_ATTR_ACTION, action), __ADD(RULE_ATTR_IIFNAME, iifname), __ADD(RULE_ATTR_OIFNAME, oifname), __ADD(RULE_ATTR_PRIO, prio), __ADD(RULE_ATTR_MARK, mark), __ADD(RULE_ATTR_MASK, mask), __ADD(RULE_ATTR_GOTO, goto), __ADD(RULE_ATTR_SRC, src), __ADD(RULE_ATTR_DST, dst), __ADD(RULE_ATTR_DSFIELD, dsfield), __ADD(RULE_ATTR_FLOW, flow), }; static char *rule_attrs2str(int attrs, char *buf, size_t len) { return __flags2str(attrs, buf, len, rule_attrs, ARRAY_SIZE(rule_attrs)); } /** * @name Allocation/Freeing * @{ */ struct rtnl_rule *rtnl_rule_alloc(void) { return (struct rtnl_rule *) nl_object_alloc(&rule_obj_ops); } void rtnl_rule_put(struct rtnl_rule *rule) { nl_object_put((struct nl_object *) rule); } /** @} */ /** * @name Cache Management * @{ */ /** * Build a rule cache including all rules currently configured in the kernel. * @arg sock Netlink socket. * @arg family Address family or AF_UNSPEC. * @arg result Pointer to store resulting cache. * * Allocates a new rule cache, initializes it properly and updates it * to include all rules currently configured in the kernel. * * @return 0 on success or a negative error code. */ int rtnl_rule_alloc_cache(struct nl_sock *sock, int family, struct nl_cache **result) { struct nl_cache * cache; int err; if (!(cache = nl_cache_alloc(&rtnl_rule_ops))) return -NLE_NOMEM; cache->c_iarg1 = family; if (sock && (err = nl_cache_refill(sock, cache)) < 0) { free(cache); return err; } *result = cache; return 0; } /** @} */ /** * @name Rule Addition * @{ */ static int build_rule_msg(struct rtnl_rule *tmpl, int cmd, int flags, struct nl_msg **result) { struct nl_msg *msg; struct fib_rule_hdr frh = { .family = tmpl->r_family, .table = tmpl->r_table, .action = tmpl->r_action, .flags = tmpl->r_flags, .tos = tmpl->r_dsfield, }; if (!(tmpl->ce_mask & RULE_ATTR_FAMILY)) return -NLE_MISSING_ATTR; msg = nlmsg_alloc_simple(cmd, flags); if (!msg) return -NLE_NOMEM; if (tmpl->ce_mask & RULE_ATTR_SRC) frh.src_len = nl_addr_get_prefixlen(tmpl->r_src); if (tmpl->ce_mask & RULE_ATTR_DST) frh.dst_len = nl_addr_get_prefixlen(tmpl->r_dst); if (nlmsg_append(msg, &frh, sizeof(frh), NLMSG_ALIGNTO) < 0) goto nla_put_failure; /* Additional table attribute replacing the 8bit in the header, was * required to allow more than 256 tables. */ NLA_PUT_U32(msg, FRA_TABLE, tmpl->r_table); if (tmpl->ce_mask & RULE_ATTR_SRC) NLA_PUT_ADDR(msg, FRA_SRC, tmpl->r_src); if (tmpl->ce_mask & RULE_ATTR_DST) NLA_PUT_ADDR(msg, FRA_DST, tmpl->r_dst); if (tmpl->ce_mask & RULE_ATTR_IIFNAME) NLA_PUT_STRING(msg, FRA_IIFNAME, tmpl->r_iifname); if (tmpl->ce_mask & RULE_ATTR_OIFNAME) NLA_PUT_STRING(msg, FRA_OIFNAME, tmpl->r_oifname); if (tmpl->ce_mask & RULE_ATTR_PRIO) NLA_PUT_U32(msg, FRA_PRIORITY, tmpl->r_prio); if (tmpl->ce_mask & RULE_ATTR_MARK) NLA_PUT_U32(msg, FRA_FWMARK, tmpl->r_mark); if (tmpl->ce_mask & RULE_ATTR_MASK) NLA_PUT_U32(msg, FRA_FWMASK, tmpl->r_mask); if (tmpl->ce_mask & RULE_ATTR_GOTO) NLA_PUT_U32(msg, FRA_GOTO, tmpl->r_goto); if (tmpl->ce_mask & RULE_ATTR_FLOW) NLA_PUT_U32(msg, FRA_FLOW, tmpl->r_flow); *result = msg; return 0; nla_put_failure: nlmsg_free(msg); return -NLE_MSGSIZE; } /** * Build netlink request message to add a new rule * @arg tmpl template with data of new rule * @arg flags additional netlink message flags * @arg result Result pointer * * Builds a new netlink message requesting a addition of a new * rule. The netlink message header isn't fully equipped with * all relevant fields and must thus be sent out via nl_send_auto_complete() * or supplemented as needed. \a tmpl must contain the attributes of the new * address set via \c rtnl_rule_set_* functions. * * @return 0 on success or a negative error code. */ int rtnl_rule_build_add_request(struct rtnl_rule *tmpl, int flags, struct nl_msg **result) { return build_rule_msg(tmpl, RTM_NEWRULE, NLM_F_CREATE | flags, result); } /** * Add a new rule * @arg sk Netlink socket. * @arg tmpl template with requested changes * @arg flags additional netlink message flags * * Builds a netlink message by calling rtnl_rule_build_add_request(), * sends the request to the kernel and waits for the next ACK to be * received and thus blocks until the request has been fullfilled. * * @return 0 on sucess or a negative error if an error occured. */ int rtnl_rule_add(struct nl_sock *sk, struct rtnl_rule *tmpl, int flags) { struct nl_msg *msg; int err; if ((err = rtnl_rule_build_add_request(tmpl, flags, &msg)) < 0) return err; err = nl_send_auto_complete(sk, msg); nlmsg_free(msg); if (err < 0) return err; return wait_for_ack(sk); } /** @} */ /** * @name Rule Deletion * @{ */ /** * Build a netlink request message to delete a rule * @arg rule rule to delete * @arg flags additional netlink message flags * @arg result Result pointer * * Builds a new netlink message requesting a deletion of a rule. * The netlink message header isn't fully equipped with all relevant * fields and must thus be sent out via nl_send_auto_complete() * or supplemented as needed. \a rule must point to an existing * address. * * @return 0 on success or a negative error code. */ int rtnl_rule_build_delete_request(struct rtnl_rule *rule, int flags, struct nl_msg **result) { return build_rule_msg(rule, RTM_DELRULE, flags, result); } /** * Delete a rule * @arg sk Netlink socket. * @arg rule rule to delete * @arg flags additional netlink message flags * * Builds a netlink message by calling rtnl_rule_build_delete_request(), * sends the request to the kernel and waits for the next ACK to be * received and thus blocks until the request has been fullfilled. * * @return 0 on sucess or a negative error if an error occured. */ int rtnl_rule_delete(struct nl_sock *sk, struct rtnl_rule *rule, int flags) { struct nl_msg *msg; int err; if ((err = rtnl_rule_build_delete_request(rule, flags, &msg)) < 0) return err; err = nl_send_auto_complete(sk, msg); nlmsg_free(msg); if (err < 0) return err; return wait_for_ack(sk); } /** @} */ /** * @name Attribute Modification * @{ */ void rtnl_rule_set_family(struct rtnl_rule *rule, int family) { rule->r_family = family; rule->ce_mask |= RULE_ATTR_FAMILY; } int rtnl_rule_get_family(struct rtnl_rule *rule) { if (rule->ce_mask & RULE_ATTR_FAMILY) return rule->r_family; else return AF_UNSPEC; } void rtnl_rule_set_prio(struct rtnl_rule *rule, uint32_t prio) { rule->r_prio = prio; rule->ce_mask |= RULE_ATTR_PRIO; } uint32_t rtnl_rule_get_prio(struct rtnl_rule *rule) { return rule->r_prio; } void rtnl_rule_set_mark(struct rtnl_rule *rule, uint32_t mark) { rule->r_mark = mark; rule->ce_mask |= RULE_ATTR_MARK; } uint32_t rtnl_rule_get_mark(struct rtnl_rule *rule) { return rule->r_mark; } void rtnl_rule_set_mask(struct rtnl_rule *rule, uint32_t mask) { rule->r_mask = mask; rule->ce_mask |= RULE_ATTR_MASK; } uint32_t rtnl_rule_get_mask(struct rtnl_rule *rule) { return rule->r_mask; } void rtnl_rule_set_table(struct rtnl_rule *rule, uint32_t table) { rule->r_table = table; rule->ce_mask |= RULE_ATTR_TABLE; } uint32_t rtnl_rule_get_table(struct rtnl_rule *rule) { return rule->r_table; } void rtnl_rule_set_dsfield(struct rtnl_rule *rule, uint8_t dsfield) { rule->r_dsfield = dsfield; rule->ce_mask |= RULE_ATTR_DSFIELD; } uint8_t rtnl_rule_get_dsfield(struct rtnl_rule *rule) { return rule->r_dsfield; } static inline int __assign_addr(struct rtnl_rule *rule, struct nl_addr **pos, struct nl_addr *new, int flag) { if (rule->ce_mask & RULE_ATTR_FAMILY) { if (new->a_family != rule->r_family) return -NLE_AF_MISMATCH; } else rule->r_family = new->a_family; if (*pos) nl_addr_put(*pos); nl_addr_get(new); *pos = new; rule->ce_mask |= (flag | RULE_ATTR_FAMILY); return 0; } int rtnl_rule_set_src(struct rtnl_rule *rule, struct nl_addr *src) { return __assign_addr(rule, &rule->r_src, src, RULE_ATTR_SRC); } struct nl_addr *rtnl_rule_get_src(struct rtnl_rule *rule) { return rule->r_src; } int rtnl_rule_set_dst(struct rtnl_rule *rule, struct nl_addr *dst) { return __assign_addr(rule, &rule->r_dst, dst, RULE_ATTR_DST); } struct nl_addr *rtnl_rule_get_dst(struct rtnl_rule *rule) { return rule->r_dst; } int rtnl_rule_set_iif(struct rtnl_rule *rule, const char *dev) { if (strlen(dev) > IFNAMSIZ-1) return -NLE_RANGE; strcpy(rule->r_iifname, dev); rule->ce_mask |= RULE_ATTR_IIFNAME; return 0; } char *rtnl_rule_get_iif(struct rtnl_rule *rule) { if (rule->ce_mask & RULE_ATTR_IIFNAME) return rule->r_iifname; else return NULL; } int rtnl_rule_set_oif(struct rtnl_rule *rule, const char *dev) { if (strlen(dev) > IFNAMSIZ-1) return -NLE_RANGE; strcpy(rule->r_oifname, dev); rule->ce_mask |= RULE_ATTR_OIFNAME; return 0; } char *rtnl_rule_get_oif(struct rtnl_rule *rule) { if (rule->ce_mask & RULE_ATTR_OIFNAME) return rule->r_oifname; else return NULL; } void rtnl_rule_set_action(struct rtnl_rule *rule, uint8_t action) { rule->r_action = action; rule->ce_mask |= RULE_ATTR_ACTION; } uint8_t rtnl_rule_get_action(struct rtnl_rule *rule) { return rule->r_action; } void rtnl_rule_set_realms(struct rtnl_rule *rule, uint32_t realms) { rule->r_flow = realms; rule->ce_mask |= RULE_ATTR_FLOW; } uint32_t rtnl_rule_get_realms(struct rtnl_rule *rule) { return rule->r_flow; } void rtnl_rule_set_goto(struct rtnl_rule *rule, uint32_t ref) { rule->r_goto = ref; rule->ce_mask |= RULE_ATTR_GOTO; } uint32_t rtnl_rule_get_goto(struct rtnl_rule *rule) { return rule->r_goto; } /** @} */ static struct nl_object_ops rule_obj_ops = { .oo_name = "route/rule", .oo_size = sizeof(struct rtnl_rule), .oo_free_data = rule_free_data, .oo_clone = rule_clone, .oo_dump = { [NL_DUMP_LINE] = rule_dump_line, [NL_DUMP_DETAILS] = rule_dump_details, [NL_DUMP_STATS] = rule_dump_stats, }, .oo_compare = rule_compare, .oo_attrs2str = rule_attrs2str, .oo_id_attrs = ~0, }; static struct nl_cache_ops rtnl_rule_ops = { .co_name = "route/rule", .co_hdrsize = sizeof(struct fib_rule_hdr), .co_msgtypes = { { RTM_NEWRULE, NL_ACT_NEW, "new" }, { RTM_DELRULE, NL_ACT_DEL, "del" }, { RTM_GETRULE, NL_ACT_GET, "get" }, END_OF_MSGTYPES_LIST, }, .co_protocol = NETLINK_ROUTE, .co_request_update = rule_request_update, .co_msg_parser = rule_msg_parser, .co_obj_ops = &rule_obj_ops, }; static void __init rule_init(void) { nl_cache_mngt_register(&rtnl_rule_ops); } static void __exit rule_exit(void) { nl_cache_mngt_unregister(&rtnl_rule_ops); } /** @} */