1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/types.h>
29 #include <sys/ck.h>
30 #include <sys/epoch.h>
31 #include <sys/kernel.h>
32 #include <sys/malloc.h>
33 #include <sys/socket.h>
34
35 #include <net/route.h>
36 #include <net/route/route_ctl.h>
37 #include <netlink/netlink.h>
38 #include <netlink/netlink_ctl.h>
39 #include <netlink/netlink_route.h>
40 #include <netlink/route/route_var.h>
41
42 #define DEBUG_MOD_NAME nl_route_core
43 #define DEBUG_MAX_LEVEL LOG_DEBUG3
44 #include <netlink/netlink_debug.h>
45 _DECLARE_DEBUG(LOG_INFO);
46
47 #define HANDLER_MAX_NUM (NL_RTM_MAX + 10)
48 static const struct rtnl_cmd_handler *rtnl_handler[HANDLER_MAX_NUM] = {};
49
50 bool
rtnl_register_messages(const struct rtnl_cmd_handler * handlers,int count)51 rtnl_register_messages(const struct rtnl_cmd_handler *handlers, int count)
52 {
53 for (int i = 0; i < count; i++) {
54 if (handlers[i].cmd >= HANDLER_MAX_NUM)
55 return (false);
56 MPASS(rtnl_handler[handlers[i].cmd] == NULL);
57 }
58 for (int i = 0; i < count; i++)
59 rtnl_handler[handlers[i].cmd] = &handlers[i];
60 return (true);
61 }
62
63 /*
64 * Handler called by netlink subsystem when matching netlink message is received
65 */
66 static int
rtnl_handle_message(struct nlmsghdr * hdr,struct nl_pstate * npt)67 rtnl_handle_message(struct nlmsghdr *hdr, struct nl_pstate *npt)
68 {
69 const struct rtnl_cmd_handler *cmd;
70 struct epoch_tracker et;
71 struct nlpcb *nlp = npt->nlp;
72 int error = 0;
73
74 if (__predict_false(hdr->nlmsg_type >= HANDLER_MAX_NUM)) {
75 NLMSG_REPORT_ERR_MSG(npt, "unknown message type: %d", hdr->nlmsg_type);
76 return (ENOTSUP);
77 }
78
79 cmd = rtnl_handler[hdr->nlmsg_type];
80 if (__predict_false(cmd == NULL)) {
81 NLMSG_REPORT_ERR_MSG(npt, "unknown message type: %d", hdr->nlmsg_type);
82 return (ENOTSUP);
83 }
84
85 NLP_LOG(LOG_DEBUG2, nlp, "received msg %s(%d) len %d", cmd->name,
86 hdr->nlmsg_type, hdr->nlmsg_len);
87
88 if (cmd->priv != 0 && !nlp_has_priv(nlp, cmd->priv)) {
89 NLP_LOG(LOG_DEBUG2, nlp, "priv %d check failed for msg %s", cmd->priv, cmd->name);
90 return (EPERM);
91 } else if (cmd->priv != 0)
92 NLP_LOG(LOG_DEBUG3, nlp, "priv %d check passed for msg %s", cmd->priv, cmd->name);
93
94 if (!nlp_unconstrained_vnet(nlp) && (cmd->flags & RTNL_F_ALLOW_NONVNET_JAIL) == 0) {
95 NLP_LOG(LOG_DEBUG2, nlp, "jail check failed for msg %s", cmd->name);
96 return (EPERM);
97 }
98
99 bool need_epoch = !(cmd->flags & RTNL_F_NOEPOCH);
100
101 if (need_epoch)
102 NET_EPOCH_ENTER(et);
103 error = cmd->cb(hdr, nlp, npt);
104 if (need_epoch)
105 NET_EPOCH_EXIT(et);
106
107 NLP_LOG(LOG_DEBUG3, nlp, "message %s -> error %d", cmd->name, error);
108
109 return (error);
110 }
111
112 static struct rtbridge nlbridge = {
113 .route_f = rtnl_handle_route_event,
114 .ifmsg_f = rtnl_handle_ifnet_event,
115 };
116 static struct rtbridge *nlbridge_orig_p;
117
118 static void
rtnl_load(void * u __unused)119 rtnl_load(void *u __unused)
120 {
121 NL_LOG(LOG_DEBUG2, "rtnl loading");
122 nlbridge_orig_p = netlink_callback_p;
123 netlink_callback_p = &nlbridge;
124 rtnl_neighs_init();
125 rtnl_ifaces_init();
126 rtnl_nexthops_init();
127 rtnl_routes_init();
128 netlink_register_proto(NETLINK_ROUTE, "NETLINK_ROUTE", rtnl_handle_message);
129 }
130 SYSINIT(rtnl_load, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, rtnl_load, NULL);
131
132 static void
rtnl_unload(void * u __unused)133 rtnl_unload(void *u __unused)
134 {
135 netlink_callback_p = nlbridge_orig_p;
136 netlink_unregister_proto(NETLINK_ROUTE);
137 rtnl_ifaces_destroy();
138 rtnl_neighs_destroy();
139
140 /* Wait till all consumers read nlbridge data */
141 NET_EPOCH_WAIT();
142 }
143 SYSUNINIT(rtnl_unload, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, rtnl_unload, NULL);
144