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 a hash table lock */ 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 net *net = sock_net(skb->sk); 199 int num, s_num, slot, s_slot; 200 struct unix_diag_req *req; 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; slot < UNIX_HASH_SIZE; s_num = 0, slot++) { 208 struct sock *sk; 209 210 num = 0; 211 spin_lock(&net->unx.table.locks[slot]); 212 sk_for_each(sk, &net->unx.table.buckets[slot]) { 213 if (num < s_num) 214 goto next; 215 if (!(req->udiag_states & (1 << sk->sk_state))) 216 goto next; 217 if (sk_diag_dump(sk, skb, req, 218 NETLINK_CB(cb->skb).portid, 219 cb->nlh->nlmsg_seq, 220 NLM_F_MULTI) < 0) { 221 spin_unlock(&net->unx.table.locks[slot]); 222 goto done; 223 } 224 next: 225 num++; 226 } 227 spin_unlock(&net->unx.table.locks[slot]); 228 } 229 done: 230 cb->args[0] = slot; 231 cb->args[1] = num; 232 233 return skb->len; 234 } 235 236 static struct sock *unix_lookup_by_ino(struct net *net, unsigned int ino) 237 { 238 struct sock *sk; 239 int i; 240 241 for (i = 0; i < UNIX_HASH_SIZE; i++) { 242 spin_lock(&net->unx.table.locks[i]); 243 sk_for_each(sk, &net->unx.table.buckets[i]) { 244 if (ino == sock_i_ino(sk)) { 245 sock_hold(sk); 246 spin_unlock(&net->unx.table.locks[i]); 247 return sk; 248 } 249 } 250 spin_unlock(&net->unx.table.locks[i]); 251 } 252 return NULL; 253 } 254 255 static int unix_diag_get_exact(struct sk_buff *in_skb, 256 const struct nlmsghdr *nlh, 257 struct unix_diag_req *req) 258 { 259 struct net *net = sock_net(in_skb->sk); 260 unsigned int extra_len; 261 struct sk_buff *rep; 262 struct sock *sk; 263 int err; 264 265 err = -EINVAL; 266 if (req->udiag_ino == 0) 267 goto out_nosk; 268 269 sk = unix_lookup_by_ino(net, req->udiag_ino); 270 err = -ENOENT; 271 if (sk == NULL) 272 goto out_nosk; 273 274 err = sock_diag_check_cookie(sk, req->udiag_cookie); 275 if (err) 276 goto out; 277 278 extra_len = 256; 279 again: 280 err = -ENOMEM; 281 rep = nlmsg_new(sizeof(struct unix_diag_msg) + extra_len, GFP_KERNEL); 282 if (!rep) 283 goto out; 284 285 err = sk_diag_fill(sk, rep, req, NETLINK_CB(in_skb).portid, 286 nlh->nlmsg_seq, 0, req->udiag_ino); 287 if (err < 0) { 288 nlmsg_free(rep); 289 extra_len += 256; 290 if (extra_len >= PAGE_SIZE) 291 goto out; 292 293 goto again; 294 } 295 err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid); 296 297 out: 298 if (sk) 299 sock_put(sk); 300 out_nosk: 301 return err; 302 } 303 304 static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h) 305 { 306 int hdrlen = sizeof(struct unix_diag_req); 307 308 if (nlmsg_len(h) < hdrlen) 309 return -EINVAL; 310 311 if (h->nlmsg_flags & NLM_F_DUMP) { 312 struct netlink_dump_control c = { 313 .dump = unix_diag_dump, 314 }; 315 return netlink_dump_start(sock_net(skb->sk)->diag_nlsk, skb, h, &c); 316 } else 317 return unix_diag_get_exact(skb, h, nlmsg_data(h)); 318 } 319 320 static const struct sock_diag_handler unix_diag_handler = { 321 .family = AF_UNIX, 322 .dump = unix_diag_handler_dump, 323 }; 324 325 static int __init unix_diag_init(void) 326 { 327 return sock_diag_register(&unix_diag_handler); 328 } 329 330 static void __exit unix_diag_exit(void) 331 { 332 sock_diag_unregister(&unix_diag_handler); 333 } 334 335 module_init(unix_diag_init); 336 module_exit(unix_diag_exit); 337 MODULE_LICENSE("GPL"); 338 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */); 339