1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <linux/types.h> 3 #include <linux/spinlock.h> 4 #include <linux/sock_diag.h> 5 #include <linux/unix_diag.h> 6 #include <linux/skbuff.h> 7 #include <linux/module.h> 8 #include <linux/uidgid.h> 9 #include <net/netlink.h> 10 #include <net/af_unix.h> 11 #include <net/tcp_states.h> 12 #include <net/sock.h> 13 14 static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb) 15 { 16 /* might or might not have unix_table_locks */ 17 struct unix_address *addr = smp_load_acquire(&unix_sk(sk)->addr); 18 19 if (!addr) 20 return 0; 21 22 return nla_put(nlskb, UNIX_DIAG_NAME, 23 addr->len - offsetof(struct sockaddr_un, sun_path), 24 addr->name->sun_path); 25 } 26 27 static int sk_diag_dump_vfs(struct sock *sk, struct sk_buff *nlskb) 28 { 29 struct dentry *dentry = unix_sk(sk)->path.dentry; 30 31 if (dentry) { 32 struct unix_diag_vfs uv = { 33 .udiag_vfs_ino = d_backing_inode(dentry)->i_ino, 34 .udiag_vfs_dev = dentry->d_sb->s_dev, 35 }; 36 37 return nla_put(nlskb, UNIX_DIAG_VFS, sizeof(uv), &uv); 38 } 39 40 return 0; 41 } 42 43 static int sk_diag_dump_peer(struct sock *sk, struct sk_buff *nlskb) 44 { 45 struct sock *peer; 46 int ino; 47 48 peer = unix_peer_get(sk); 49 if (peer) { 50 unix_state_lock(peer); 51 ino = sock_i_ino(peer); 52 unix_state_unlock(peer); 53 sock_put(peer); 54 55 return nla_put_u32(nlskb, UNIX_DIAG_PEER, ino); 56 } 57 58 return 0; 59 } 60 61 static int sk_diag_dump_icons(struct sock *sk, struct sk_buff *nlskb) 62 { 63 struct sk_buff *skb; 64 struct nlattr *attr; 65 u32 *buf; 66 int i; 67 68 if (sk->sk_state == TCP_LISTEN) { 69 spin_lock(&sk->sk_receive_queue.lock); 70 71 attr = nla_reserve(nlskb, UNIX_DIAG_ICONS, 72 sk->sk_receive_queue.qlen * sizeof(u32)); 73 if (!attr) 74 goto errout; 75 76 buf = nla_data(attr); 77 i = 0; 78 skb_queue_walk(&sk->sk_receive_queue, skb) { 79 struct sock *req, *peer; 80 81 req = skb->sk; 82 /* 83 * The state lock is outer for the same sk's 84 * queue lock. With the other's queue locked it's 85 * OK to lock the state. 86 */ 87 unix_state_lock_nested(req); 88 peer = unix_sk(req)->peer; 89 buf[i++] = (peer ? sock_i_ino(peer) : 0); 90 unix_state_unlock(req); 91 } 92 spin_unlock(&sk->sk_receive_queue.lock); 93 } 94 95 return 0; 96 97 errout: 98 spin_unlock(&sk->sk_receive_queue.lock); 99 return -EMSGSIZE; 100 } 101 102 static int sk_diag_show_rqlen(struct sock *sk, struct sk_buff *nlskb) 103 { 104 struct unix_diag_rqlen rql; 105 106 if (sk->sk_state == TCP_LISTEN) { 107 rql.udiag_rqueue = sk->sk_receive_queue.qlen; 108 rql.udiag_wqueue = sk->sk_max_ack_backlog; 109 } else { 110 rql.udiag_rqueue = (u32) unix_inq_len(sk); 111 rql.udiag_wqueue = (u32) unix_outq_len(sk); 112 } 113 114 return nla_put(nlskb, UNIX_DIAG_RQLEN, sizeof(rql), &rql); 115 } 116 117 static int sk_diag_dump_uid(struct sock *sk, struct sk_buff *nlskb) 118 { 119 uid_t uid = from_kuid_munged(sk_user_ns(nlskb->sk), sock_i_uid(sk)); 120 return nla_put(nlskb, UNIX_DIAG_UID, sizeof(uid_t), &uid); 121 } 122 123 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req, 124 u32 portid, u32 seq, u32 flags, int sk_ino) 125 { 126 struct nlmsghdr *nlh; 127 struct unix_diag_msg *rep; 128 129 nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep), 130 flags); 131 if (!nlh) 132 return -EMSGSIZE; 133 134 rep = nlmsg_data(nlh); 135 rep->udiag_family = AF_UNIX; 136 rep->udiag_type = sk->sk_type; 137 rep->udiag_state = sk->sk_state; 138 rep->pad = 0; 139 rep->udiag_ino = sk_ino; 140 sock_diag_save_cookie(sk, rep->udiag_cookie); 141 142 if ((req->udiag_show & UDIAG_SHOW_NAME) && 143 sk_diag_dump_name(sk, skb)) 144 goto out_nlmsg_trim; 145 146 if ((req->udiag_show & UDIAG_SHOW_VFS) && 147 sk_diag_dump_vfs(sk, skb)) 148 goto out_nlmsg_trim; 149 150 if ((req->udiag_show & UDIAG_SHOW_PEER) && 151 sk_diag_dump_peer(sk, skb)) 152 goto out_nlmsg_trim; 153 154 if ((req->udiag_show & UDIAG_SHOW_ICONS) && 155 sk_diag_dump_icons(sk, skb)) 156 goto out_nlmsg_trim; 157 158 if ((req->udiag_show & UDIAG_SHOW_RQLEN) && 159 sk_diag_show_rqlen(sk, skb)) 160 goto out_nlmsg_trim; 161 162 if ((req->udiag_show & UDIAG_SHOW_MEMINFO) && 163 sock_diag_put_meminfo(sk, skb, UNIX_DIAG_MEMINFO)) 164 goto out_nlmsg_trim; 165 166 if (nla_put_u8(skb, UNIX_DIAG_SHUTDOWN, sk->sk_shutdown)) 167 goto out_nlmsg_trim; 168 169 if ((req->udiag_show & UDIAG_SHOW_UID) && 170 sk_diag_dump_uid(sk, skb)) 171 goto out_nlmsg_trim; 172 173 nlmsg_end(skb, nlh); 174 return 0; 175 176 out_nlmsg_trim: 177 nlmsg_cancel(skb, nlh); 178 return -EMSGSIZE; 179 } 180 181 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req, 182 u32 portid, u32 seq, u32 flags) 183 { 184 int sk_ino; 185 186 unix_state_lock(sk); 187 sk_ino = sock_i_ino(sk); 188 unix_state_unlock(sk); 189 190 if (!sk_ino) 191 return 0; 192 193 return sk_diag_fill(sk, skb, req, portid, seq, flags, sk_ino); 194 } 195 196 static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb) 197 { 198 struct unix_diag_req *req; 199 int num, s_num, slot, s_slot; 200 struct net *net = sock_net(skb->sk); 201 202 req = nlmsg_data(cb->nlh); 203 204 s_slot = cb->args[0]; 205 num = s_num = cb->args[1]; 206 207 for (slot = s_slot; 208 slot < ARRAY_SIZE(unix_socket_table); 209 s_num = 0, slot++) { 210 struct sock *sk; 211 212 num = 0; 213 spin_lock(&unix_table_locks[slot]); 214 sk_for_each(sk, &unix_socket_table[slot]) { 215 if (!net_eq(sock_net(sk), net)) 216 continue; 217 if (num < s_num) 218 goto next; 219 if (!(req->udiag_states & (1 << sk->sk_state))) 220 goto next; 221 if (sk_diag_dump(sk, skb, req, 222 NETLINK_CB(cb->skb).portid, 223 cb->nlh->nlmsg_seq, 224 NLM_F_MULTI) < 0) { 225 spin_unlock(&unix_table_locks[slot]); 226 goto done; 227 } 228 next: 229 num++; 230 } 231 spin_unlock(&unix_table_locks[slot]); 232 } 233 done: 234 cb->args[0] = slot; 235 cb->args[1] = num; 236 237 return skb->len; 238 } 239 240 static struct sock *unix_lookup_by_ino(unsigned int ino) 241 { 242 struct sock *sk; 243 int i; 244 245 for (i = 0; i < ARRAY_SIZE(unix_socket_table); i++) { 246 spin_lock(&unix_table_locks[i]); 247 sk_for_each(sk, &unix_socket_table[i]) 248 if (ino == sock_i_ino(sk)) { 249 sock_hold(sk); 250 spin_unlock(&unix_table_locks[i]); 251 return sk; 252 } 253 spin_unlock(&unix_table_locks[i]); 254 } 255 return NULL; 256 } 257 258 static int unix_diag_get_exact(struct sk_buff *in_skb, 259 const struct nlmsghdr *nlh, 260 struct unix_diag_req *req) 261 { 262 int err = -EINVAL; 263 struct sock *sk; 264 struct sk_buff *rep; 265 unsigned int extra_len; 266 struct net *net = sock_net(in_skb->sk); 267 268 if (req->udiag_ino == 0) 269 goto out_nosk; 270 271 sk = unix_lookup_by_ino(req->udiag_ino); 272 err = -ENOENT; 273 if (sk == NULL) 274 goto out_nosk; 275 if (!net_eq(sock_net(sk), net)) 276 goto out; 277 278 err = sock_diag_check_cookie(sk, req->udiag_cookie); 279 if (err) 280 goto out; 281 282 extra_len = 256; 283 again: 284 err = -ENOMEM; 285 rep = nlmsg_new(sizeof(struct unix_diag_msg) + extra_len, GFP_KERNEL); 286 if (!rep) 287 goto out; 288 289 err = sk_diag_fill(sk, rep, req, NETLINK_CB(in_skb).portid, 290 nlh->nlmsg_seq, 0, req->udiag_ino); 291 if (err < 0) { 292 nlmsg_free(rep); 293 extra_len += 256; 294 if (extra_len >= PAGE_SIZE) 295 goto out; 296 297 goto again; 298 } 299 err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid); 300 301 out: 302 if (sk) 303 sock_put(sk); 304 out_nosk: 305 return err; 306 } 307 308 static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h) 309 { 310 int hdrlen = sizeof(struct unix_diag_req); 311 struct net *net = sock_net(skb->sk); 312 313 if (nlmsg_len(h) < hdrlen) 314 return -EINVAL; 315 316 if (h->nlmsg_flags & NLM_F_DUMP) { 317 struct netlink_dump_control c = { 318 .dump = unix_diag_dump, 319 }; 320 return netlink_dump_start(net->diag_nlsk, skb, h, &c); 321 } else 322 return unix_diag_get_exact(skb, h, nlmsg_data(h)); 323 } 324 325 static const struct sock_diag_handler unix_diag_handler = { 326 .family = AF_UNIX, 327 .dump = unix_diag_handler_dump, 328 }; 329 330 static int __init unix_diag_init(void) 331 { 332 return sock_diag_register(&unix_diag_handler); 333 } 334 335 static void __exit unix_diag_exit(void) 336 { 337 sock_diag_unregister(&unix_diag_handler); 338 } 339 340 module_init(unix_diag_init); 341 module_exit(unix_diag_exit); 342 MODULE_LICENSE("GPL"); 343 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */); 344