1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2023 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 "opt_netlink.h" 29 30 #include <sys/param.h> 31 #include <sys/kernel.h> 32 #include <sys/malloc.h> 33 #include <sys/lock.h> 34 #include <sys/rmlock.h> 35 #include <sys/domain.h> 36 #include <sys/mbuf.h> 37 #include <sys/protosw.h> 38 #include <sys/proc.h> 39 #include <sys/ck.h> 40 #include <sys/socket.h> 41 #include <sys/socketvar.h> 42 #include <sys/sysent.h> 43 #include <sys/syslog.h> 44 #include <sys/priv.h> /* priv_check */ 45 46 #include <net/route.h> 47 #include <net/route/route_ctl.h> 48 49 #include <netlink/netlink.h> 50 #include <netlink/netlink_ctl.h> 51 #include <netlink/netlink_var.h> 52 #include <netlink/route/route_var.h> 53 54 /* Standard bits: built-in the kernel */ 55 SYSCTL_NODE(_net, OID_AUTO, netlink, CTLFLAG_RD, 0, ""); 56 SYSCTL_NODE(_net_netlink, OID_AUTO, debug, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, ""); 57 58 MALLOC_DEFINE(M_NETLINK, "netlink", "Memory used for netlink packets"); 59 60 /* Netlink-related callbacks needed to glue rtsock, netlink and linuxolator */ 61 static void 62 ignore_route_event(uint32_t fibnum, const struct rib_cmd_info *rc) 63 { 64 } 65 66 static void 67 ignore_ifmsg_event(struct ifnet *ifp, int if_flags_mask) 68 { 69 } 70 71 static struct rtbridge ignore_cb = { 72 .route_f = ignore_route_event, 73 .ifmsg_f = ignore_ifmsg_event, 74 }; 75 76 void *linux_netlink_p = NULL; /* Callback pointer for Linux translator functions */ 77 struct rtbridge *rtsock_callback_p = &ignore_cb; 78 struct rtbridge *netlink_callback_p = &ignore_cb; 79 80 81 /* 82 * nlp accessors. 83 * TODO: move to a separate file once the number grows. 84 */ 85 bool 86 nlp_has_priv(struct nlpcb *nlp, int priv) 87 { 88 return (priv_check_cred(nlp->nl_cred, priv) == 0); 89 } 90 91 struct ucred * 92 nlp_get_cred(struct nlpcb *nlp) 93 { 94 return (nlp->nl_cred); 95 } 96 97 uint32_t 98 nlp_get_pid(const struct nlpcb *nlp) 99 { 100 return (nlp->nl_process_id); 101 } 102 103 bool 104 nlp_unconstrained_vnet(const struct nlpcb *nlp) 105 { 106 return (nlp->nl_unconstrained_vnet); 107 } 108 109 #ifndef NETLINK 110 /* Stub implementations for the loadable functions */ 111 112 static bool 113 get_stub_writer(struct nl_writer *nw) 114 { 115 bzero(nw, sizeof(*nw)); 116 nw->writer_type = NS_WRITER_TYPE_STUB; 117 nw->enomem = true; 118 119 return (false); 120 } 121 122 static bool 123 nlmsg_get_unicast_writer_stub(struct nl_writer *nw, int size, struct nlpcb *nlp) 124 { 125 return (get_stub_writer(nw)); 126 } 127 128 static bool 129 nlmsg_get_group_writer_stub(struct nl_writer *nw, int size, int protocol, int group_id) 130 { 131 return (get_stub_writer(nw)); 132 } 133 134 static bool 135 nlmsg_get_chain_writer_stub(struct nl_writer *nw, int size, struct mbuf **pm) 136 { 137 return (get_stub_writer(nw)); 138 } 139 140 static bool 141 nlmsg_flush_stub(struct nl_writer *nw __unused) 142 { 143 return (false); 144 } 145 146 static void 147 nlmsg_ignore_limit_stub(struct nl_writer *nw __unused) 148 { 149 } 150 151 static bool 152 nlmsg_refill_buffer_stub(struct nl_writer *nw __unused, int required_len __unused) 153 { 154 return (false); 155 } 156 157 static bool 158 nlmsg_add_stub(struct nl_writer *nw, uint32_t portid, uint32_t seq, uint16_t type, 159 uint16_t flags, uint32_t len) 160 { 161 return (false); 162 } 163 164 static bool 165 nlmsg_end_stub(struct nl_writer *nw __unused) 166 { 167 return (false); 168 } 169 170 static void 171 nlmsg_abort_stub(struct nl_writer *nw __unused) 172 { 173 } 174 175 static bool 176 nlmsg_end_dump_stub(struct nl_writer *nw, int error, struct nlmsghdr *hdr) 177 { 178 return (false); 179 } 180 181 static int 182 nl_modify_ifp_generic_stub(struct ifnet *ifp __unused, 183 struct nl_parsed_link *lattrs __unused, const struct nlattr_bmask *bm __unused, 184 struct nl_pstate *npt __unused) 185 { 186 return (ENOTSUP); 187 } 188 189 static void 190 nl_store_ifp_cookie_stub(struct nl_pstate *npt __unused, struct ifnet *ifp __unused) 191 { 192 } 193 194 static struct nlpcb * 195 nl_get_thread_nlp_stub(struct thread *td __unused) 196 { 197 return (NULL); 198 } 199 200 const static struct nl_function_wrapper nl_stub = { 201 .nlmsg_add = nlmsg_add_stub, 202 .nlmsg_refill_buffer = nlmsg_refill_buffer_stub, 203 .nlmsg_flush = nlmsg_flush_stub, 204 .nlmsg_end = nlmsg_end_stub, 205 .nlmsg_abort = nlmsg_abort_stub, 206 .nlmsg_ignore_limit = nlmsg_ignore_limit_stub, 207 .nlmsg_get_unicast_writer = nlmsg_get_unicast_writer_stub, 208 .nlmsg_get_group_writer = nlmsg_get_group_writer_stub, 209 .nlmsg_get_chain_writer = nlmsg_get_chain_writer_stub, 210 .nlmsg_end_dump = nlmsg_end_dump_stub, 211 .nl_modify_ifp_generic = nl_modify_ifp_generic_stub, 212 .nl_store_ifp_cookie = nl_store_ifp_cookie_stub, 213 .nl_get_thread_nlp = nl_get_thread_nlp_stub, 214 }; 215 216 /* 217 * If the kernel is compiled with netlink as a module, 218 * provide a way to introduce non-stub functioms 219 */ 220 static const struct nl_function_wrapper *_nl = &nl_stub; 221 222 void 223 nl_set_functions(const struct nl_function_wrapper *nl) 224 { 225 _nl = (nl != NULL) ? nl : &nl_stub; 226 } 227 228 /* Function wrappers */ 229 bool 230 nlmsg_get_unicast_writer(struct nl_writer *nw, int size, struct nlpcb *nlp) 231 { 232 return (_nl->nlmsg_get_unicast_writer(nw, size, nlp)); 233 } 234 235 bool 236 nlmsg_get_group_writer(struct nl_writer *nw, int size, int protocol, int group_id) 237 { 238 return (_nl->nlmsg_get_group_writer(nw, size, protocol, group_id)); 239 } 240 241 bool 242 nlmsg_get_chain_writer(struct nl_writer *nw, int size, struct mbuf **pm) 243 { 244 return (_nl->nlmsg_get_chain_writer(nw, size, pm)); 245 } 246 247 bool 248 nlmsg_flush(struct nl_writer *nw) 249 { 250 return (_nl->nlmsg_flush(nw)); 251 } 252 253 void nlmsg_ignore_limit(struct nl_writer *nw) 254 { 255 _nl->nlmsg_ignore_limit(nw); 256 } 257 258 bool 259 nlmsg_refill_buffer(struct nl_writer *nw, int required_len) 260 { 261 return (_nl->nlmsg_refill_buffer(nw, required_len)); 262 } 263 264 bool 265 nlmsg_add(struct nl_writer *nw, uint32_t portid, uint32_t seq, uint16_t type, 266 uint16_t flags, uint32_t len) 267 { 268 return (_nl->nlmsg_add(nw, portid, seq, type, flags, len)); 269 } 270 271 bool 272 nlmsg_end(struct nl_writer *nw) 273 { 274 return (_nl->nlmsg_end(nw)); 275 } 276 277 void 278 nlmsg_abort(struct nl_writer *nw) 279 { 280 _nl->nlmsg_abort(nw); 281 } 282 283 bool 284 nlmsg_end_dump(struct nl_writer *nw, int error, struct nlmsghdr *hdr) 285 { 286 return (_nl->nlmsg_end_dump(nw, error, hdr)); 287 } 288 289 int 290 nl_modify_ifp_generic(struct ifnet *ifp, struct nl_parsed_link *lattrs, 291 const struct nlattr_bmask *bm , struct nl_pstate *npt) 292 { 293 return (_nl->nl_modify_ifp_generic(ifp, lattrs, bm, npt)); 294 } 295 296 void 297 nl_store_ifp_cookie(struct nl_pstate *npt, struct ifnet *ifp) 298 { 299 return (_nl->nl_store_ifp_cookie(npt, ifp)); 300 } 301 302 struct nlpcb * 303 nl_get_thread_nlp(struct thread *td) 304 { 305 return (_nl->nl_get_thread_nlp(td)); 306 } 307 308 #endif /* !NETLINK */ 309 310