/net/socket.c
C | 3444 lines | 2484 code | 499 blank | 461 comment | 387 complexity | 84930f052a3fd0f89ffb7ef85196472a MD5 | raw file
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1/* 2 * NET An implementation of the SOCKET network access protocol. 3 * 4 * Version: @(#)socket.c 1.1.93 18/02/95 5 * 6 * Authors: Orest Zborowski, <obz@Kodak.COM> 7 * Ross Biro 8 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 9 * 10 * Fixes: 11 * Anonymous : NOTSOCK/BADF cleanup. Error fix in 12 * shutdown() 13 * Alan Cox : verify_area() fixes 14 * Alan Cox : Removed DDI 15 * Jonathan Kamens : SOCK_DGRAM reconnect bug 16 * Alan Cox : Moved a load of checks to the very 17 * top level. 18 * Alan Cox : Move address structures to/from user 19 * mode above the protocol layers. 20 * Rob Janssen : Allow 0 length sends. 21 * Alan Cox : Asynchronous I/O support (cribbed from the 22 * tty drivers). 23 * Niibe Yutaka : Asynchronous I/O for writes (4.4BSD style) 24 * Jeff Uphoff : Made max number of sockets command-line 25 * configurable. 26 * Matti Aarnio : Made the number of sockets dynamic, 27 * to be allocated when needed, and mr. 28 * Uphoff's max is used as max to be 29 * allowed to allocate. 30 * Linus : Argh. removed all the socket allocation 31 * altogether: it's in the inode now. 32 * Alan Cox : Made sock_alloc()/sock_release() public 33 * for NetROM and future kernel nfsd type 34 * stuff. 35 * Alan Cox : sendmsg/recvmsg basics. 36 * Tom Dyas : Export net symbols. 37 * Marcin Dalecki : Fixed problems with CONFIG_NET="n". 38 * Alan Cox : Added thread locking to sys_* calls 39 * for sockets. May have errors at the 40 * moment. 41 * Kevin Buhr : Fixed the dumb errors in the above. 42 * Andi Kleen : Some small cleanups, optimizations, 43 * and fixed a copy_from_user() bug. 44 * Tigran Aivazian : sys_send(args) calls sys_sendto(args, NULL, 0) 45 * Tigran Aivazian : Made listen(2) backlog sanity checks 46 * protocol-independent 47 * 48 * 49 * This program is free software; you can redistribute it and/or 50 * modify it under the terms of the GNU General Public License 51 * as published by the Free Software Foundation; either version 52 * 2 of the License, or (at your option) any later version. 53 * 54 * 55 * This module is effectively the top level interface to the BSD socket 56 * paradigm. 57 * 58 * Based upon Swansea University Computer Society NET3.039 59 */ 60 61#include <linux/mm.h> 62#include <linux/socket.h> 63#include <linux/file.h> 64#include <linux/net.h> 65#include <linux/interrupt.h> 66#include <linux/thread_info.h> 67#include <linux/rcupdate.h> 68#include <linux/netdevice.h> 69#include <linux/proc_fs.h> 70#include <linux/seq_file.h> 71#include <linux/mutex.h> 72#include <linux/if_bridge.h> 73#include <linux/if_frad.h> 74#include <linux/if_vlan.h> 75#include <linux/ptp_classify.h> 76#include <linux/init.h> 77#include <linux/poll.h> 78#include <linux/cache.h> 79#include <linux/module.h> 80#include <linux/highmem.h> 81#include <linux/mount.h> 82#include <linux/security.h> 83#include <linux/syscalls.h> 84#include <linux/compat.h> 85#include <linux/kmod.h> 86#include <linux/audit.h> 87#include <linux/wireless.h> 88#include <linux/nsproxy.h> 89#include <linux/magic.h> 90#include <linux/slab.h> 91#include <linux/xattr.h> 92 93#include <linux/uaccess.h> 94#include <asm/unistd.h> 95 96#include <net/compat.h> 97#include <net/wext.h> 98#include <net/cls_cgroup.h> 99 100#include <net/sock.h> 101#include <linux/netfilter.h> 102 103#include <linux/if_tun.h> 104#include <linux/ipv6_route.h> 105#include <linux/route.h> 106#include <linux/sockios.h> 107#include <linux/atalk.h> 108#include <net/busy_poll.h> 109#include <linux/errqueue.h> 110 111#ifdef CONFIG_NET_RX_BUSY_POLL 112unsigned int sysctl_net_busy_read __read_mostly; 113unsigned int sysctl_net_busy_poll __read_mostly; 114#endif 115 116static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to); 117static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from); 118static int sock_mmap(struct file *file, struct vm_area_struct *vma); 119 120static int sock_close(struct inode *inode, struct file *file); 121static unsigned int sock_poll(struct file *file, 122 struct poll_table_struct *wait); 123static long sock_ioctl(struct file *file, unsigned int cmd, unsigned long arg); 124#ifdef CONFIG_COMPAT 125static long compat_sock_ioctl(struct file *file, 126 unsigned int cmd, unsigned long arg); 127#endif 128static int sock_fasync(int fd, struct file *filp, int on); 129static ssize_t sock_sendpage(struct file *file, struct page *page, 130 int offset, size_t size, loff_t *ppos, int more); 131static ssize_t sock_splice_read(struct file *file, loff_t *ppos, 132 struct pipe_inode_info *pipe, size_t len, 133 unsigned int flags); 134 135/* 136 * Socket files have a set of 'special' operations as well as the generic file ones. These don't appear 137 * in the operation structures but are done directly via the socketcall() multiplexor. 138 */ 139 140static const struct file_operations socket_file_ops = { 141 .owner = THIS_MODULE, 142 .llseek = no_llseek, 143 .read_iter = sock_read_iter, 144 .write_iter = sock_write_iter, 145 .poll = sock_poll, 146 .unlocked_ioctl = sock_ioctl, 147#ifdef CONFIG_COMPAT 148 .compat_ioctl = compat_sock_ioctl, 149#endif 150 .mmap = sock_mmap, 151 .release = sock_close, 152 .fasync = sock_fasync, 153 .sendpage = sock_sendpage, 154 .splice_write = generic_splice_sendpage, 155 .splice_read = sock_splice_read, 156}; 157 158/* 159 * The protocol list. Each protocol is registered in here. 160 */ 161 162static DEFINE_SPINLOCK(net_family_lock); 163static const struct net_proto_family __rcu *net_families[NPROTO] __read_mostly; 164 165/* 166 * Statistics counters of the socket lists 167 */ 168 169static DEFINE_PER_CPU(int, sockets_in_use); 170 171/* 172 * Support routines. 173 * Move socket addresses back and forth across the kernel/user 174 * divide and look after the messy bits. 175 */ 176 177/** 178 * move_addr_to_kernel - copy a socket address into kernel space 179 * @uaddr: Address in user space 180 * @kaddr: Address in kernel space 181 * @ulen: Length in user space 182 * 183 * The address is copied into kernel space. If the provided address is 184 * too long an error code of -EINVAL is returned. If the copy gives 185 * invalid addresses -EFAULT is returned. On a success 0 is returned. 186 */ 187 188int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr) 189{ 190 if (ulen < 0 || ulen > sizeof(struct sockaddr_storage)) 191 return -EINVAL; 192 if (ulen == 0) 193 return 0; 194 if (copy_from_user(kaddr, uaddr, ulen)) 195 return -EFAULT; 196 return audit_sockaddr(ulen, kaddr); 197} 198 199/** 200 * move_addr_to_user - copy an address to user space 201 * @kaddr: kernel space address 202 * @klen: length of address in kernel 203 * @uaddr: user space address 204 * @ulen: pointer to user length field 205 * 206 * The value pointed to by ulen on entry is the buffer length available. 207 * This is overwritten with the buffer space used. -EINVAL is returned 208 * if an overlong buffer is specified or a negative buffer size. -EFAULT 209 * is returned if either the buffer or the length field are not 210 * accessible. 211 * After copying the data up to the limit the user specifies, the true 212 * length of the data is written over the length limit the user 213 * specified. Zero is returned for a success. 214 */ 215 216static int move_addr_to_user(struct sockaddr_storage *kaddr, int klen, 217 void __user *uaddr, int __user *ulen) 218{ 219 int err; 220 int len; 221 222 BUG_ON(klen > sizeof(struct sockaddr_storage)); 223 err = get_user(len, ulen); 224 if (err) 225 return err; 226 if (len > klen) 227 len = klen; 228 if (len < 0) 229 return -EINVAL; 230 if (len) { 231 if (audit_sockaddr(klen, kaddr)) 232 return -ENOMEM; 233 if (copy_to_user(uaddr, kaddr, len)) 234 return -EFAULT; 235 } 236 /* 237 * "fromlen shall refer to the value before truncation.." 238 * 1003.1g 239 */ 240 return __put_user(klen, ulen); 241} 242 243static struct kmem_cache *sock_inode_cachep __read_mostly; 244 245static struct inode *sock_alloc_inode(struct super_block *sb) 246{ 247 struct socket_alloc *ei; 248 struct socket_wq *wq; 249 250 ei = kmem_cache_alloc(sock_inode_cachep, GFP_KERNEL); 251 if (!ei) 252 return NULL; 253 wq = kmalloc(sizeof(*wq), GFP_KERNEL); 254 if (!wq) { 255 kmem_cache_free(sock_inode_cachep, ei); 256 return NULL; 257 } 258 init_waitqueue_head(&wq->wait); 259 wq->fasync_list = NULL; 260 wq->flags = 0; 261 RCU_INIT_POINTER(ei->socket.wq, wq); 262 263 ei->socket.state = SS_UNCONNECTED; 264 ei->socket.flags = 0; 265 ei->socket.ops = NULL; 266 ei->socket.sk = NULL; 267 ei->socket.file = NULL; 268 269 return &ei->vfs_inode; 270} 271 272static void sock_destroy_inode(struct inode *inode) 273{ 274 struct socket_alloc *ei; 275 struct socket_wq *wq; 276 277 ei = container_of(inode, struct socket_alloc, vfs_inode); 278 wq = rcu_dereference_protected(ei->socket.wq, 1); 279 kfree_rcu(wq, rcu); 280 kmem_cache_free(sock_inode_cachep, ei); 281} 282 283static void init_once(void *foo) 284{ 285 struct socket_alloc *ei = (struct socket_alloc *)foo; 286 287 inode_init_once(&ei->vfs_inode); 288} 289 290static void init_inodecache(void) 291{ 292 sock_inode_cachep = kmem_cache_create("sock_inode_cache", 293 sizeof(struct socket_alloc), 294 0, 295 (SLAB_HWCACHE_ALIGN | 296 SLAB_RECLAIM_ACCOUNT | 297 SLAB_MEM_SPREAD | SLAB_ACCOUNT), 298 init_once); 299 BUG_ON(sock_inode_cachep == NULL); 300} 301 302static const struct super_operations sockfs_ops = { 303 .alloc_inode = sock_alloc_inode, 304 .destroy_inode = sock_destroy_inode, 305 .statfs = simple_statfs, 306}; 307 308/* 309 * sockfs_dname() is called from d_path(). 310 */ 311static char *sockfs_dname(struct dentry *dentry, char *buffer, int buflen) 312{ 313 return dynamic_dname(dentry, buffer, buflen, "socket:[%lu]", 314 d_inode(dentry)->i_ino); 315} 316 317static const struct dentry_operations sockfs_dentry_operations = { 318 .d_dname = sockfs_dname, 319}; 320 321static int sockfs_xattr_get(const struct xattr_handler *handler, 322 struct dentry *dentry, struct inode *inode, 323 const char *suffix, void *value, size_t size) 324{ 325 if (value) { 326 if (dentry->d_name.len + 1 > size) 327 return -ERANGE; 328 memcpy(value, dentry->d_name.name, dentry->d_name.len + 1); 329 } 330 return dentry->d_name.len + 1; 331} 332 333#define XATTR_SOCKPROTONAME_SUFFIX "sockprotoname" 334#define XATTR_NAME_SOCKPROTONAME (XATTR_SYSTEM_PREFIX XATTR_SOCKPROTONAME_SUFFIX) 335#define XATTR_NAME_SOCKPROTONAME_LEN (sizeof(XATTR_NAME_SOCKPROTONAME)-1) 336 337static const struct xattr_handler sockfs_xattr_handler = { 338 .name = XATTR_NAME_SOCKPROTONAME, 339 .get = sockfs_xattr_get, 340}; 341 342static int sockfs_security_xattr_set(const struct xattr_handler *handler, 343 struct dentry *dentry, struct inode *inode, 344 const char *suffix, const void *value, 345 size_t size, int flags) 346{ 347 /* Handled by LSM. */ 348 return -EAGAIN; 349} 350 351static const struct xattr_handler sockfs_security_xattr_handler = { 352 .prefix = XATTR_SECURITY_PREFIX, 353 .set = sockfs_security_xattr_set, 354}; 355 356static const struct xattr_handler *sockfs_xattr_handlers[] = { 357 &sockfs_xattr_handler, 358 &sockfs_security_xattr_handler, 359 NULL 360}; 361 362static struct dentry *sockfs_mount(struct file_system_type *fs_type, 363 int flags, const char *dev_name, void *data) 364{ 365 return mount_pseudo_xattr(fs_type, "socket:", &sockfs_ops, 366 sockfs_xattr_handlers, 367 &sockfs_dentry_operations, SOCKFS_MAGIC); 368} 369 370static struct vfsmount *sock_mnt __read_mostly; 371 372static struct file_system_type sock_fs_type = { 373 .name = "sockfs", 374 .mount = sockfs_mount, 375 .kill_sb = kill_anon_super, 376}; 377 378/* 379 * Obtains the first available file descriptor and sets it up for use. 380 * 381 * These functions create file structures and maps them to fd space 382 * of the current process. On success it returns file descriptor 383 * and file struct implicitly stored in sock->file. 384 * Note that another thread may close file descriptor before we return 385 * from this function. We use the fact that now we do not refer 386 * to socket after mapping. If one day we will need it, this 387 * function will increment ref. count on file by 1. 388 * 389 * In any case returned fd MAY BE not valid! 390 * This race condition is unavoidable 391 * with shared fd spaces, we cannot solve it inside kernel, 392 * but we take care of internal coherence yet. 393 */ 394 395struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname) 396{ 397 struct qstr name = { .name = "" }; 398 struct path path; 399 struct file *file; 400 401 if (dname) { 402 name.name = dname; 403 name.len = strlen(name.name); 404 } else if (sock->sk) { 405 name.name = sock->sk->sk_prot_creator->name; 406 name.len = strlen(name.name); 407 } 408 path.dentry = d_alloc_pseudo(sock_mnt->mnt_sb, &name); 409 if (unlikely(!path.dentry)) 410 return ERR_PTR(-ENOMEM); 411 path.mnt = mntget(sock_mnt); 412 413 d_instantiate(path.dentry, SOCK_INODE(sock)); 414 415 file = alloc_file(&path, FMODE_READ | FMODE_WRITE, 416 &socket_file_ops); 417 if (IS_ERR(file)) { 418 /* drop dentry, keep inode */ 419 ihold(d_inode(path.dentry)); 420 path_put(&path); 421 return file; 422 } 423 424 sock->file = file; 425 file->f_flags = O_RDWR | (flags & O_NONBLOCK); 426 file->private_data = sock; 427 return file; 428} 429EXPORT_SYMBOL(sock_alloc_file); 430 431static int sock_map_fd(struct socket *sock, int flags) 432{ 433 struct file *newfile; 434 int fd = get_unused_fd_flags(flags); 435 if (unlikely(fd < 0)) 436 return fd; 437 438 newfile = sock_alloc_file(sock, flags, NULL); 439 if (likely(!IS_ERR(newfile))) { 440 fd_install(fd, newfile); 441 return fd; 442 } 443 444 put_unused_fd(fd); 445 return PTR_ERR(newfile); 446} 447 448struct socket *sock_from_file(struct file *file, int *err) 449{ 450 if (file->f_op == &socket_file_ops) 451 return file->private_data; /* set in sock_map_fd */ 452 453 *err = -ENOTSOCK; 454 return NULL; 455} 456EXPORT_SYMBOL(sock_from_file); 457 458/** 459 * sockfd_lookup - Go from a file number to its socket slot 460 * @fd: file handle 461 * @err: pointer to an error code return 462 * 463 * The file handle passed in is locked and the socket it is bound 464 * to is returned. If an error occurs the err pointer is overwritten 465 * with a negative errno code and NULL is returned. The function checks 466 * for both invalid handles and passing a handle which is not a socket. 467 * 468 * On a success the socket object pointer is returned. 469 */ 470 471struct socket *sockfd_lookup(int fd, int *err) 472{ 473 struct file *file; 474 struct socket *sock; 475 476 file = fget(fd); 477 if (!file) { 478 *err = -EBADF; 479 return NULL; 480 } 481 482 sock = sock_from_file(file, err); 483 if (!sock) 484 fput(file); 485 return sock; 486} 487EXPORT_SYMBOL(sockfd_lookup); 488 489static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed) 490{ 491 struct fd f = fdget(fd); 492 struct socket *sock; 493 494 *err = -EBADF; 495 if (f.file) { 496 sock = sock_from_file(f.file, err); 497 if (likely(sock)) { 498 *fput_needed = f.flags; 499 return sock; 500 } 501 fdput(f); 502 } 503 return NULL; 504} 505 506static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer, 507 size_t size) 508{ 509 ssize_t len; 510 ssize_t used = 0; 511 512 len = security_inode_listsecurity(d_inode(dentry), buffer, size); 513 if (len < 0) 514 return len; 515 used += len; 516 if (buffer) { 517 if (size < used) 518 return -ERANGE; 519 buffer += len; 520 } 521 522 len = (XATTR_NAME_SOCKPROTONAME_LEN + 1); 523 used += len; 524 if (buffer) { 525 if (size < used) 526 return -ERANGE; 527 memcpy(buffer, XATTR_NAME_SOCKPROTONAME, len); 528 buffer += len; 529 } 530 531 return used; 532} 533 534static int sockfs_setattr(struct dentry *dentry, struct iattr *iattr) 535{ 536 int err = simple_setattr(dentry, iattr); 537 538 if (!err && (iattr->ia_valid & ATTR_UID)) { 539 struct socket *sock = SOCKET_I(d_inode(dentry)); 540 541 sock->sk->sk_uid = iattr->ia_uid; 542 } 543 544 return err; 545} 546 547static const struct inode_operations sockfs_inode_ops = { 548 .listxattr = sockfs_listxattr, 549 .setattr = sockfs_setattr, 550}; 551 552/** 553 * sock_alloc - allocate a socket 554 * 555 * Allocate a new inode and socket object. The two are bound together 556 * and initialised. The socket is then returned. If we are out of inodes 557 * NULL is returned. 558 */ 559 560struct socket *sock_alloc(void) 561{ 562 struct inode *inode; 563 struct socket *sock; 564 565 inode = new_inode_pseudo(sock_mnt->mnt_sb); 566 if (!inode) 567 return NULL; 568 569 sock = SOCKET_I(inode); 570 571 kmemcheck_annotate_bitfield(sock, type); 572 inode->i_ino = get_next_ino(); 573 inode->i_mode = S_IFSOCK | S_IRWXUGO; 574 inode->i_uid = current_fsuid(); 575 inode->i_gid = current_fsgid(); 576 inode->i_op = &sockfs_inode_ops; 577 578 this_cpu_add(sockets_in_use, 1); 579 return sock; 580} 581EXPORT_SYMBOL(sock_alloc); 582 583/** 584 * sock_release - close a socket 585 * @sock: socket to close 586 * 587 * The socket is released from the protocol stack if it has a release 588 * callback, and the inode is then released if the socket is bound to 589 * an inode not a file. 590 */ 591 592void sock_release(struct socket *sock) 593{ 594 if (sock->ops) { 595 struct module *owner = sock->ops->owner; 596 597 sock->ops->release(sock); 598 sock->ops = NULL; 599 module_put(owner); 600 } 601 602 if (rcu_dereference_protected(sock->wq, 1)->fasync_list) 603 pr_err("%s: fasync list not empty!\n", __func__); 604 605 this_cpu_sub(sockets_in_use, 1); 606 if (!sock->file) { 607 iput(SOCK_INODE(sock)); 608 return; 609 } 610 sock->file = NULL; 611} 612EXPORT_SYMBOL(sock_release); 613 614void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags) 615{ 616 u8 flags = *tx_flags; 617 618 if (tsflags & SOF_TIMESTAMPING_TX_HARDWARE) 619 flags |= SKBTX_HW_TSTAMP; 620 621 if (tsflags & SOF_TIMESTAMPING_TX_SOFTWARE) 622 flags |= SKBTX_SW_TSTAMP; 623 624 if (tsflags & SOF_TIMESTAMPING_TX_SCHED) 625 flags |= SKBTX_SCHED_TSTAMP; 626 627 *tx_flags = flags; 628} 629EXPORT_SYMBOL(__sock_tx_timestamp); 630 631static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg) 632{ 633 int ret = sock->ops->sendmsg(sock, msg, msg_data_left(msg)); 634 BUG_ON(ret == -EIOCBQUEUED); 635 return ret; 636} 637 638int sock_sendmsg(struct socket *sock, struct msghdr *msg) 639{ 640 int err = security_socket_sendmsg(sock, msg, 641 msg_data_left(msg)); 642 643 return err ?: sock_sendmsg_nosec(sock, msg); 644} 645EXPORT_SYMBOL(sock_sendmsg); 646 647int kernel_sendmsg(struct socket *sock, struct msghdr *msg, 648 struct kvec *vec, size_t num, size_t size) 649{ 650 iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC, vec, num, size); 651 return sock_sendmsg(sock, msg); 652} 653EXPORT_SYMBOL(kernel_sendmsg); 654 655static bool skb_is_err_queue(const struct sk_buff *skb) 656{ 657 /* pkt_type of skbs enqueued on the error queue are set to 658 * PACKET_OUTGOING in skb_set_err_queue(). This is only safe to do 659 * in recvmsg, since skbs received on a local socket will never 660 * have a pkt_type of PACKET_OUTGOING. 661 */ 662 return skb->pkt_type == PACKET_OUTGOING; 663} 664 665/* On transmit, software and hardware timestamps are returned independently. 666 * As the two skb clones share the hardware timestamp, which may be updated 667 * before the software timestamp is received, a hardware TX timestamp may be 668 * returned only if there is no software TX timestamp. Ignore false software 669 * timestamps, which may be made in the __sock_recv_timestamp() call when the 670 * option SO_TIMESTAMP(NS) is enabled on the socket, even when the skb has a 671 * hardware timestamp. 672 */ 673static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp) 674{ 675 return skb->tstamp && !false_tstamp && skb_is_err_queue(skb); 676} 677 678static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb) 679{ 680 struct scm_ts_pktinfo ts_pktinfo; 681 struct net_device *orig_dev; 682 683 if (!skb_mac_header_was_set(skb)) 684 return; 685 686 memset(&ts_pktinfo, 0, sizeof(ts_pktinfo)); 687 688 rcu_read_lock(); 689 orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); 690 if (orig_dev) 691 ts_pktinfo.if_index = orig_dev->ifindex; 692 rcu_read_unlock(); 693 694 ts_pktinfo.pkt_length = skb->len - skb_mac_offset(skb); 695 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO, 696 sizeof(ts_pktinfo), &ts_pktinfo); 697} 698 699/* 700 * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP) 701 */ 702void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, 703 struct sk_buff *skb) 704{ 705 int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP); 706 struct scm_timestamping tss; 707 int empty = 1, false_tstamp = 0; 708 struct skb_shared_hwtstamps *shhwtstamps = 709 skb_hwtstamps(skb); 710 711 /* Race occurred between timestamp enabling and packet 712 receiving. Fill in the current time for now. */ 713 if (need_software_tstamp && skb->tstamp == 0) { 714 __net_timestamp(skb); 715 false_tstamp = 1; 716 } 717 718 if (need_software_tstamp) { 719 if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) { 720 struct timeval tv; 721 skb_get_timestamp(skb, &tv); 722 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP, 723 sizeof(tv), &tv); 724 } else { 725 struct timespec ts; 726 skb_get_timestampns(skb, &ts); 727 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS, 728 sizeof(ts), &ts); 729 } 730 } 731 732 memset(&tss, 0, sizeof(tss)); 733 if ((sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) && 734 ktime_to_timespec_cond(skb->tstamp, tss.ts + 0)) 735 empty = 0; 736 if (shhwtstamps && 737 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) && 738 !skb_is_swtx_tstamp(skb, false_tstamp) && 739 ktime_to_timespec_cond(shhwtstamps->hwtstamp, tss.ts + 2)) { 740 empty = 0; 741 if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) && 742 !skb_is_err_queue(skb)) 743 put_ts_pktinfo(msg, skb); 744 } 745 if (!empty) { 746 put_cmsg(msg, SOL_SOCKET, 747 SCM_TIMESTAMPING, sizeof(tss), &tss); 748 749 if (skb_is_err_queue(skb) && skb->len && 750 SKB_EXT_ERR(skb)->opt_stats) 751 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_OPT_STATS, 752 skb->len, skb->data); 753 } 754} 755EXPORT_SYMBOL_GPL(__sock_recv_timestamp); 756 757void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk, 758 struct sk_buff *skb) 759{ 760 int ack; 761 762 if (!sock_flag(sk, SOCK_WIFI_STATUS)) 763 return; 764 if (!skb->wifi_acked_valid) 765 return; 766 767 ack = skb->wifi_acked; 768 769 put_cmsg(msg, SOL_SOCKET, SCM_WIFI_STATUS, sizeof(ack), &ack); 770} 771EXPORT_SYMBOL_GPL(__sock_recv_wifi_status); 772 773static inline void sock_recv_drops(struct msghdr *msg, struct sock *sk, 774 struct sk_buff *skb) 775{ 776 if (sock_flag(sk, SOCK_RXQ_OVFL) && skb && SOCK_SKB_CB(skb)->dropcount) 777 put_cmsg(msg, SOL_SOCKET, SO_RXQ_OVFL, 778 sizeof(__u32), &SOCK_SKB_CB(skb)->dropcount); 779} 780 781void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, 782 struct sk_buff *skb) 783{ 784 sock_recv_timestamp(msg, sk, skb); 785 sock_recv_drops(msg, sk, skb); 786} 787EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops); 788 789static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg, 790 int flags) 791{ 792 return sock->ops->recvmsg(sock, msg, msg_data_left(msg), flags); 793} 794 795int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags) 796{ 797 int err = security_socket_recvmsg(sock, msg, msg_data_left(msg), flags); 798 799 return err ?: sock_recvmsg_nosec(sock, msg, flags); 800} 801EXPORT_SYMBOL(sock_recvmsg); 802 803/** 804 * kernel_recvmsg - Receive a message from a socket (kernel space) 805 * @sock: The socket to receive the message from 806 * @msg: Received message 807 * @vec: Input s/g array for message data 808 * @num: Size of input s/g array 809 * @size: Number of bytes to read 810 * @flags: Message flags (MSG_DONTWAIT, etc...) 811 * 812 * On return the msg structure contains the scatter/gather array passed in the 813 * vec argument. The array is modified so that it consists of the unfilled 814 * portion of the original array. 815 * 816 * The returned value is the total number of bytes received, or an error. 817 */ 818int kernel_recvmsg(struct socket *sock, struct msghdr *msg, 819 struct kvec *vec, size_t num, size_t size, int flags) 820{ 821 mm_segment_t oldfs = get_fs(); 822 int result; 823 824 iov_iter_kvec(&msg->msg_iter, READ | ITER_KVEC, vec, num, size); 825 set_fs(KERNEL_DS); 826 result = sock_recvmsg(sock, msg, flags); 827 set_fs(oldfs); 828 return result; 829} 830EXPORT_SYMBOL(kernel_recvmsg); 831 832static ssize_t sock_sendpage(struct file *file, struct page *page, 833 int offset, size_t size, loff_t *ppos, int more) 834{ 835 struct socket *sock; 836 int flags; 837 838 sock = file->private_data; 839 840 flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0; 841 /* more is a combination of MSG_MORE and MSG_SENDPAGE_NOTLAST */ 842 flags |= more; 843 844 return kernel_sendpage(sock, page, offset, size, flags); 845} 846 847static ssize_t sock_splice_read(struct file *file, loff_t *ppos, 848 struct pipe_inode_info *pipe, size_t len, 849 unsigned int flags) 850{ 851 struct socket *sock = file->private_data; 852 853 if (unlikely(!sock->ops->splice_read)) 854 return -EINVAL; 855 856 return sock->ops->splice_read(sock, ppos, pipe, len, flags); 857} 858 859static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to) 860{ 861 struct file *file = iocb->ki_filp; 862 struct socket *sock = file->private_data; 863 struct msghdr msg = {.msg_iter = *to, 864 .msg_iocb = iocb}; 865 ssize_t res; 866 867 if (file->f_flags & O_NONBLOCK) 868 msg.msg_flags = MSG_DONTWAIT; 869 870 if (iocb->ki_pos != 0) 871 return -ESPIPE; 872 873 if (!iov_iter_count(to)) /* Match SYS5 behaviour */ 874 return 0; 875 876 res = sock_recvmsg(sock, &msg, msg.msg_flags); 877 *to = msg.msg_iter; 878 return res; 879} 880 881static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from) 882{ 883 struct file *file = iocb->ki_filp; 884 struct socket *sock = file->private_data; 885 struct msghdr msg = {.msg_iter = *from, 886 .msg_iocb = iocb}; 887 ssize_t res; 888 889 if (iocb->ki_pos != 0) 890 return -ESPIPE; 891 892 if (file->f_flags & O_NONBLOCK) 893 msg.msg_flags = MSG_DONTWAIT; 894 895 if (sock->type == SOCK_SEQPACKET) 896 msg.msg_flags |= MSG_EOR; 897 898 res = sock_sendmsg(sock, &msg); 899 *from = msg.msg_iter; 900 return res; 901} 902 903/* 904 * Atomic setting of ioctl hooks to avoid race 905 * with module unload. 906 */ 907 908static DEFINE_MUTEX(br_ioctl_mutex); 909static int (*br_ioctl_hook) (struct net *, unsigned int cmd, void __user *arg); 910 911void brioctl_set(int (*hook) (struct net *, unsigned int, void __user *)) 912{ 913 mutex_lock(&br_ioctl_mutex); 914 br_ioctl_hook = hook; 915 mutex_unlock(&br_ioctl_mutex); 916} 917EXPORT_SYMBOL(brioctl_set); 918 919static DEFINE_MUTEX(vlan_ioctl_mutex); 920static int (*vlan_ioctl_hook) (struct net *, void __user *arg); 921 922void vlan_ioctl_set(int (*hook) (struct net *, void __user *)) 923{ 924 mutex_lock(&vlan_ioctl_mutex); 925 vlan_ioctl_hook = hook; 926 mutex_unlock(&vlan_ioctl_mutex); 927} 928EXPORT_SYMBOL(vlan_ioctl_set); 929 930static DEFINE_MUTEX(dlci_ioctl_mutex); 931static int (*dlci_ioctl_hook) (unsigned int, void __user *); 932 933void dlci_ioctl_set(int (*hook) (unsigned int, void __user *)) 934{ 935 mutex_lock(&dlci_ioctl_mutex); 936 dlci_ioctl_hook = hook; 937 mutex_unlock(&dlci_ioctl_mutex); 938} 939EXPORT_SYMBOL(dlci_ioctl_set); 940 941static long sock_do_ioctl(struct net *net, struct socket *sock, 942 unsigned int cmd, unsigned long arg) 943{ 944 int err; 945 void __user *argp = (void __user *)arg; 946 947 err = sock->ops->ioctl(sock, cmd, arg); 948 949 /* 950 * If this ioctl is unknown try to hand it down 951 * to the NIC driver. 952 */ 953 if (err == -ENOIOCTLCMD) 954 err = dev_ioctl(net, cmd, argp); 955 956 return err; 957} 958 959/* 960 * With an ioctl, arg may well be a user mode pointer, but we don't know 961 * what to do with it - that's up to the protocol still. 962 */ 963 964static struct ns_common *get_net_ns(struct ns_common *ns) 965{ 966 return &get_net(container_of(ns, struct net, ns))->ns; 967} 968 969static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg) 970{ 971 struct socket *sock; 972 struct sock *sk; 973 void __user *argp = (void __user *)arg; 974 int pid, err; 975 struct net *net; 976 977 sock = file->private_data; 978 sk = sock->sk; 979 net = sock_net(sk); 980 if (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15)) { 981 err = dev_ioctl(net, cmd, argp); 982 } else 983#ifdef CONFIG_WEXT_CORE 984 if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) { 985 err = dev_ioctl(net, cmd, argp); 986 } else 987#endif 988 switch (cmd) { 989 case FIOSETOWN: 990 case SIOCSPGRP: 991 err = -EFAULT; 992 if (get_user(pid, (int __user *)argp)) 993 break; 994 err = f_setown(sock->file, pid, 1); 995 break; 996 case FIOGETOWN: 997 case SIOCGPGRP: 998 err = put_user(f_getown(sock->file), 999 (int __user *)argp); 1000 break; 1001 case SIOCGIFBR: 1002 case SIOCSIFBR: 1003 case SIOCBRADDBR: 1004 case SIOCBRDELBR: 1005 err = -ENOPKG; 1006 if (!br_ioctl_hook) 1007 request_module("bridge"); 1008 1009 mutex_lock(&br_ioctl_mutex); 1010 if (br_ioctl_hook) 1011 err = br_ioctl_hook(net, cmd, argp); 1012 mutex_unlock(&br_ioctl_mutex); 1013 break; 1014 case SIOCGIFVLAN: 1015 case SIOCSIFVLAN: 1016 err = -ENOPKG; 1017 if (!vlan_ioctl_hook) 1018 request_module("8021q"); 1019 1020 mutex_lock(&vlan_ioctl_mutex); 1021 if (vlan_ioctl_hook) 1022 err = vlan_ioctl_hook(net, argp); 1023 mutex_unlock(&vlan_ioctl_mutex); 1024 break; 1025 case SIOCADDDLCI: 1026 case SIOCDELDLCI: 1027 err = -ENOPKG; 1028 if (!dlci_ioctl_hook) 1029 request_module("dlci"); 1030 1031 mutex_lock(&dlci_ioctl_mutex); 1032 if (dlci_ioctl_hook) 1033 err = dlci_ioctl_hook(cmd, argp); 1034 mutex_unlock(&dlci_ioctl_mutex); 1035 break; 1036 case SIOCGSKNS: 1037 err = -EPERM; 1038 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1039 break; 1040 1041 err = open_related_ns(&net->ns, get_net_ns); 1042 break; 1043 default: 1044 err = sock_do_ioctl(net, sock, cmd, arg); 1045 break; 1046 } 1047 return err; 1048} 1049 1050int sock_create_lite(int family, int type, int protocol, struct socket **res) 1051{ 1052 int err; 1053 struct socket *sock = NULL; 1054 1055 err = security_socket_create(family, type, protocol, 1); 1056 if (err) 1057 goto out; 1058 1059 sock = sock_alloc(); 1060 if (!sock) { 1061 err = -ENOMEM; 1062 goto out; 1063 } 1064 1065 sock->type = type; 1066 err = security_socket_post_create(sock, family, type, protocol, 1); 1067 if (err) 1068 goto out_release; 1069 1070out: 1071 *res = sock; 1072 return err; 1073out_release: 1074 sock_release(sock); 1075 sock = NULL; 1076 goto out; 1077} 1078EXPORT_SYMBOL(sock_create_lite); 1079 1080/* No kernel lock held - perfect */ 1081static unsigned int sock_poll(struct file *file, poll_table *wait) 1082{ 1083 unsigned int busy_flag = 0; 1084 struct socket *sock; 1085 1086 /* 1087 * We can't return errors to poll, so it's either yes or no. 1088 */ 1089 sock = file->private_data; 1090 1091 if (sk_can_busy_loop(sock->sk)) { 1092 /* this socket can poll_ll so tell the system call */ 1093 busy_flag = POLL_BUSY_LOOP; 1094 1095 /* once, only if requested by syscall */ 1096 if (wait && (wait->_key & POLL_BUSY_LOOP)) 1097 sk_busy_loop(sock->sk, 1); 1098 } 1099 1100 return busy_flag | sock->ops->poll(file, sock, wait); 1101} 1102 1103static int sock_mmap(struct file *file, struct vm_area_struct *vma) 1104{ 1105 struct socket *sock = file->private_data; 1106 1107 return sock->ops->mmap(file, sock, vma); 1108} 1109 1110static int sock_close(struct inode *inode, struct file *filp) 1111{ 1112 sock_release(SOCKET_I(inode)); 1113 return 0; 1114} 1115 1116/* 1117 * Update the socket async list 1118 * 1119 * Fasync_list locking strategy. 1120 * 1121 * 1. fasync_list is modified only under process context socket lock 1122 * i.e. under semaphore. 1123 * 2. fasync_list is used under read_lock(&sk->sk_callback_lock) 1124 * or under socket lock 1125 */ 1126 1127static int sock_fasync(int fd, struct file *filp, int on) 1128{ 1129 struct socket *sock = filp->private_data; 1130 struct sock *sk = sock->sk; 1131 struct socket_wq *wq; 1132 1133 if (sk == NULL) 1134 return -EINVAL; 1135 1136 lock_sock(sk); 1137 wq = rcu_dereference_protected(sock->wq, lockdep_sock_is_held(sk)); 1138 fasync_helper(fd, filp, on, &wq->fasync_list); 1139 1140 if (!wq->fasync_list) 1141 sock_reset_flag(sk, SOCK_FASYNC); 1142 else 1143 sock_set_flag(sk, SOCK_FASYNC); 1144 1145 release_sock(sk); 1146 return 0; 1147} 1148 1149/* This function may be called only under rcu_lock */ 1150 1151int sock_wake_async(struct socket_wq *wq, int how, int band) 1152{ 1153 if (!wq || !wq->fasync_list) 1154 return -1; 1155 1156 switch (how) { 1157 case SOCK_WAKE_WAITD: 1158 if (test_bit(SOCKWQ_ASYNC_WAITDATA, &wq->flags)) 1159 break; 1160 goto call_kill; 1161 case SOCK_WAKE_SPACE: 1162 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags)) 1163 break; 1164 /* fall through */ 1165 case SOCK_WAKE_IO: 1166call_kill: 1167 kill_fasync(&wq->fasync_list, SIGIO, band); 1168 break; 1169 case SOCK_WAKE_URG: 1170 kill_fasync(&wq->fasync_list, SIGURG, band); 1171 } 1172 1173 return 0; 1174} 1175EXPORT_SYMBOL(sock_wake_async); 1176 1177int __sock_create(struct net *net, int family, int type, int protocol, 1178 struct socket **res, int kern) 1179{ 1180 int err; 1181 struct socket *sock; 1182 const struct net_proto_family *pf; 1183 1184 /* 1185 * Check protocol is in range 1186 */ 1187 if (family < 0 || family >= NPROTO) 1188 return -EAFNOSUPPORT; 1189 if (type < 0 || type >= SOCK_MAX) 1190 return -EINVAL; 1191 1192 /* Compatibility. 1193 1194 This uglymoron is moved from INET layer to here to avoid 1195 deadlock in module load. 1196 */ 1197 if (family == PF_INET && type == SOCK_PACKET) { 1198 pr_info_once("%s uses obsolete (PF_INET,SOCK_PACKET)\n", 1199 current->comm); 1200 family = PF_PACKET; 1201 } 1202 1203 err = security_socket_create(family, type, protocol, kern); 1204 if (err) 1205 return err; 1206 1207 /* 1208 * Allocate the socket and allow the family to set things up. if 1209 * the protocol is 0, the family is instructed to select an appropriate 1210 * default. 1211 */ 1212 sock = sock_alloc(); 1213 if (!sock) { 1214 net_warn_ratelimited("socket: no more sockets\n"); 1215 return -ENFILE; /* Not exactly a match, but its the 1216 closest posix thing */ 1217 } 1218 1219 sock->type = type; 1220 1221#ifdef CONFIG_MODULES 1222 /* Attempt to load a protocol module if the find failed. 1223 * 1224 * 12/09/1996 Marcin: But! this makes REALLY only sense, if the user 1225 * requested real, full-featured networking support upon configuration. 1226 * Otherwise module support will break! 1227 */ 1228 if (rcu_access_pointer(net_families[family]) == NULL) 1229 request_module("net-pf-%d", family); 1230#endif 1231 1232 rcu_read_lock(); 1233 pf = rcu_dereference(net_families[family]); 1234 err = -EAFNOSUPPORT; 1235 if (!pf) 1236 goto out_release; 1237 1238 /* 1239 * We will call the ->create function, that possibly is in a loadable 1240 * module, so we have to bump that loadable module refcnt first. 1241 */ 1242 if (!try_module_get(pf->owner)) 1243 goto out_release; 1244 1245 /* Now protected by module ref count */ 1246 rcu_read_unlock(); 1247 1248 err = pf->create(net, sock, protocol, kern); 1249 if (err < 0) 1250 goto out_module_put; 1251 1252 /* 1253 * Now to bump the refcnt of the [loadable] module that owns this 1254 * socket at sock_release time we decrement its refcnt. 1255 */ 1256 if (!try_module_get(sock->ops->owner)) 1257 goto out_module_busy; 1258 1259 /* 1260 * Now that we're done with the ->create function, the [loadable] 1261 * module can have its refcnt decremented 1262 */ 1263 module_put(pf->owner); 1264 err = security_socket_post_create(sock, family, type, protocol, kern); 1265 if (err) 1266 goto out_sock_release; 1267 *res = sock; 1268 1269 return 0; 1270 1271out_module_busy: 1272 err = -EAFNOSUPPORT; 1273out_module_put: 1274 sock->ops = NULL; 1275 module_put(pf->owner); 1276out_sock_release: 1277 sock_release(sock); 1278 return err; 1279 1280out_release: 1281 rcu_read_unlock(); 1282 goto out_sock_release; 1283} 1284EXPORT_SYMBOL(__sock_create); 1285 1286int sock_create(int family, int type, int protocol, struct socket **res) 1287{ 1288 return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0); 1289} 1290EXPORT_SYMBOL(sock_create); 1291 1292int sock_create_kern(struct net *net, int family, int type, int protocol, struct socket **res) 1293{ 1294 return __sock_create(net, family, type, protocol, res, 1); 1295} 1296EXPORT_SYMBOL(sock_create_kern); 1297 1298SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol) 1299{ 1300 int retval; 1301 struct socket *sock; 1302 int flags; 1303 1304 /* Check the SOCK_* constants for consistency. */ 1305 BUILD_BUG_ON(SOCK_CLOEXEC != O_CLOEXEC); 1306 BUILD_BUG_ON((SOCK_MAX | SOCK_TYPE_MASK) != SOCK_TYPE_MASK); 1307 BUILD_BUG_ON(SOCK_CLOEXEC & SOCK_TYPE_MASK); 1308 BUILD_BUG_ON(SOCK_NONBLOCK & SOCK_TYPE_MASK); 1309 1310 flags = type & ~SOCK_TYPE_MASK; 1311 if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK)) 1312 return -EINVAL; 1313 type &= SOCK_TYPE_MASK; 1314 1315 if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK)) 1316 flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK; 1317 1318 retval = sock_create(family, type, protocol, &sock); 1319 if (retval < 0) 1320 goto out; 1321 1322 retval = sock_map_fd(sock, flags & (O_CLOEXEC | O_NONBLOCK)); 1323 if (retval < 0) 1324 goto out_release; 1325 1326out: 1327 /* It may be already another descriptor 8) Not kernel problem. */ 1328 return retval; 1329 1330out_release: 1331 sock_release(sock); 1332 return retval; 1333} 1334 1335/* 1336 * Create a pair of connected sockets. 1337 */ 1338 1339SYSCALL_DEFINE4(socketpair, int, family, int, type, int, protocol, 1340 int __user *, usockvec) 1341{ 1342 struct socket *sock1, *sock2; 1343 int fd1, fd2, err; 1344 struct file *newfile1, *newfile2; 1345 int flags; 1346 1347 flags = type & ~SOCK_TYPE_MASK; 1348 if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK)) 1349 return -EINVAL; 1350 type &= SOCK_TYPE_MASK; 1351 1352 if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK)) 1353 flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK; 1354 1355 /* 1356 * Obtain the first socket and check if the underlying protocol 1357 * supports the socketpair call. 1358 */ 1359 1360 err = sock_create(family, type, protocol, &sock1); 1361 if (err < 0) 1362 goto out; 1363 1364 err = sock_create(family, type, protocol, &sock2); 1365 if (err < 0) 1366 goto out_release_1; 1367 1368 err = sock1->ops->socketpair(sock1, sock2); 1369 if (err < 0) 1370 goto out_release_both; 1371 1372 fd1 = get_unused_fd_flags(flags); 1373 if (unlikely(fd1 < 0)) { 1374 err = fd1; 1375 goto out_release_both; 1376 } 1377 1378 fd2 = get_unused_fd_flags(flags); 1379 if (unlikely(fd2 < 0)) { 1380 err = fd2; 1381 goto out_put_unused_1; 1382 } 1383 1384 newfile1 = sock_alloc_file(sock1, flags, NULL); 1385 if (IS_ERR(newfile1)) { 1386 err = PTR_ERR(newfile1); 1387 goto out_put_unused_both; 1388 } 1389 1390 newfile2 = sock_alloc_file(sock2, flags, NULL); 1391 if (IS_ERR(newfile2)) { 1392 err = PTR_ERR(newfile2); 1393 goto out_fput_1; 1394 } 1395 1396 err = put_user(fd1, &usockvec[0]); 1397 if (err) 1398 goto out_fput_both; 1399 1400 err = put_user(fd2, &usockvec[1]); 1401 if (err) 1402 goto out_fput_both; 1403 1404 audit_fd_pair(fd1, fd2); 1405 1406 fd_install(fd1, newfile1); 1407 fd_install(fd2, newfile2); 1408 /* fd1 and fd2 may be already another descriptors. 1409 * Not kernel problem. 1410 */ 1411 1412 return 0; 1413 1414out_fput_both: 1415 fput(newfile2); 1416 fput(newfile1); 1417 put_unused_fd(fd2); 1418 put_unused_fd(fd1); 1419 goto out; 1420 1421out_fput_1: 1422 fput(newfile1); 1423 put_unused_fd(fd2); 1424 put_unused_fd(fd1); 1425 sock_release(sock2); 1426 goto out; 1427 1428out_put_unused_both: 1429 put_unused_fd(fd2); 1430out_put_unused_1: 1431 put_unused_fd(fd1); 1432out_release_both: 1433 sock_release(sock2); 1434out_release_1: 1435 sock_release(sock1); 1436out: 1437 return err; 1438} 1439 1440/* 1441 * Bind a name to a socket. Nothing much to do here since it's 1442 * the protocol's responsibility to handle the local address. 1443 * 1444 * We move the socket address to kernel space before we call 1445 * the protocol layer (having also checked the address is ok). 1446 */ 1447 1448SYSCALL_DEFINE3(bind, int, fd, struct sockaddr __user *, umyaddr, int, addrlen) 1449{ 1450 struct socket *sock; 1451 struct sockaddr_storage address; 1452 int err, fput_needed; 1453 1454 sock = sockfd_lookup_light(fd, &err, &fput_needed); 1455 if (sock) { 1456 err = move_addr_to_kernel(umyaddr, addrlen, &address); 1457 if (err >= 0) { 1458 err = security_socket_bind(sock, 1459 (struct sockaddr *)&address, 1460 addrlen); 1461 if (!err) 1462 err = sock->ops->bind(sock, 1463 (struct sockaddr *) 1464 &address, addrlen); 1465 } 1466 fput_light(sock->file, fput_needed); 1467 } 1468 return err; 1469} 1470 1471/* 1472 * Perform a listen. Basically, we allow the protocol to do anything 1473 * necessary for a listen, and if that works, we mark the socket as 1474 * ready for listening. 1475 */ 1476 1477SYSCALL_DEFINE2(listen, int, fd, int, backlog) 1478{ 1479 struct socket *sock; 1480 int err, fput_needed; 1481 int somaxconn; 1482 1483 sock = sockfd_lookup_light(fd, &err, &fput_needed); 1484 if (sock) { 1485 somaxconn = sock_net(sock->sk)->core.sysctl_somaxconn; 1486 if ((unsigned int)backlog > somaxconn) 1487 backlog = somaxconn; 1488 1489 err = security_socket_listen(sock, backlog); 1490 if (!err) 1491 err = sock->ops->listen(sock, backlog); 1492 1493 fput_light(sock->file, fput_needed); 1494 } 1495 return err; 1496} 1497 1498/* 1499 * For accept, we attempt to create a new socket, set up the link 1500 * with the client, wake up the client, then return the new 1501 * connected fd. We collect the address of the connector in kernel 1502 * space and move it to user at the very end. This is unclean because 1503 * we open the socket then return an error. 1504 * 1505 * 1003.1g adds the ability to recvmsg() to query connection pending 1506 * status to recvmsg. We need to add that support in a way thats 1507 * clean when we restucture accept also. 1508 */ 1509 1510SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr, 1511 int __user *, upeer_addrlen, int, flags) 1512{ 1513 struct socket *sock, *newsock; 1514 struct file *newfile; 1515 int err, len, newfd, fput_needed; 1516 struct sockaddr_storage address; 1517 1518 if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK)) 1519 return -EINVAL; 1520 1521 if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK)) 1522 flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK; 1523 1524 sock = sockfd_lookup_light(fd, &err, &fput_needed); 1525 if (!sock) 1526 goto out; 1527 1528 err = -ENFILE; 1529 newsock = sock_alloc(); 1530 if (!newsock) 1531 goto out_put; 1532 1533 newsock->type = sock->type; 1534 newsock->ops = sock->ops; 1535 1536 /* 1537 * We don't need try_module_get here, as the listening socket (sock) 1538 * has the protocol module (sock->ops->owner) held. 1539 */ 1540 __module_get(newsock->ops->owner); 1541 1542 newfd = get_unused_fd_flags(flags); 1543 if (unlikely(newfd < 0)) { 1544 err = newfd; 1545 sock_release(newsock); 1546 goto out_put; 1547 } 1548 newfile = sock_alloc_file(newsock, flags, sock->sk->sk_prot_creator->name); 1549 if (IS_ERR(newfile)) { 1550 err = PTR_ERR(newfile); 1551 put_unused_fd(newfd); 1552 sock_release(newsock); 1553 goto out_put; 1554 } 1555 1556 err = security_socket_accept(sock, newsock); 1557 if (err) 1558 goto out_fd; 1559 1560 err = sock->ops->accept(sock, newsock, sock->file->f_flags, false); 1561 if (err < 0) 1562 goto out_fd; 1563 1564 if (upeer_sockaddr) { 1565 if (newsock->ops->getname(newsock, (struct sockaddr *)&address, 1566 &len, 2) < 0) { 1567 err = -ECONNABORTED; 1568 goto out_fd; 1569 } 1570 err = move_addr_to_user(&address, 1571 len, upeer_sockaddr, upeer_addrlen); 1572 if (err < 0) 1573 goto out_fd; 1574 } 1575 1576 /* File flags are not inherited via accept() unlike another OSes. */ 1577 1578 fd_install(newfd, newfile); 1579 err = newfd; 1580 1581out_put: 1582 fput_light(sock->file, fput_needed); 1583out: 1584 return err; 1585out_fd: 1586 fput(newfile); 1587 put_unused_fd(newfd); 1588 goto out_put; 1589} 1590 1591SYSCALL_DEFINE3(accept, int, fd, struct sockaddr __user *, upeer_sockaddr, 1592 int __user *, upeer_addrlen) 1593{ 1594 return sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0); 1595} 1596 1597/* 1598 * Attempt to connect to a socket with the server address. The address 1599 * is in user space so we verify it is OK and move it to kernel space. 1600 * 1601 * For 1003.1g we need to add clean support for a bind to AF_UNSPEC to 1602 * break bindings 1603 * 1604 * NOTE: 1003.1g draft 6.3 is broken with respect to AX.25/NetROM and 1605 * other SEQPACKET protocols that take time to connect() as it doesn't 1606 * include the -EINPROGRESS status for such sockets. 1607 */ 1608 1609SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr, 1610 int, addrlen) 1611{ 1612 struct socket *sock; 1613 struct sockaddr_storage address; 1614 int err, fput_needed; 1615 1616 sock = sockfd_lookup_light(fd, &err, &fput_needed); 1617 if (!sock) 1618 goto out; 1619 err = move_addr_to_kernel(uservaddr, addrlen, &address); 1620 if (err < 0) 1621 goto out_put; 1622 1623 err = 1624 security_socket_connect(sock, (struct sockaddr *)&address, addrlen); 1625 if (err) 1626 goto out_put; 1627 1628 err = sock->ops->connect(sock, (struct sockaddr *)&address, addrlen, 1629 sock->file->f_flags); 1630out_put: 1631 fput_light(sock->file, fput_needed); 1632out: 1633 return err; 1634} 1635 1636/* 1637 * Get the local address ('name') of a socket object. Move the obtained 1638 * name to user space. 1639 */ 1640 1641SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr, 1642 int __user *, usockaddr_len) 1643{ 1644 struct socket *sock; 1645 struct sockaddr_storage address; 1646 int len, err, fput_needed; 1647 1648 sock = sockfd_lookup_light(fd, &err, &fput_needed); 1649 if (!sock) 1650 goto out; 1651 1652 err = security_socket_getsockname(sock); 1653 if (err) 1654 goto out_put; 1655 1656 err = sock->ops->getname(sock, (struct sockaddr *)&address, &len, 0); 1657 if (err) 1658 goto out_put; 1659 err = move_addr_to_user(&address, len, usockaddr, usockaddr_len); 1660 1661out_put: 1662 fput_light(sock->file, fput_needed); 1663out: 1664 return err; 1665} 1666 1667/* 1668 * Get the remote address ('name') of a socket object. Move the obtained 1669 * name to user space. 1670 */ 1671 1672SYSCALL_DEFINE3(getpeername, int, fd, struct sockaddr __user *, usockaddr, 1673 int __user *, usockaddr_len) 1674{ 1675 struct socket *sock; 1676 struct sockaddr_storage address; 1677 int len, err, fput_needed; 1678 1679 sock = sockfd_lookup_light(fd, &err, &fput_needed); 1680 if (sock != NULL) { 1681 err = security_socket_getpeername(sock); 1682 if (err) { 1683 fput_light(sock->file, fput_needed); 1684 return err; 1685 } 1686 1687 err = 1688 sock->ops->getname(sock, (struct sockaddr *)&address, &len, 1689 1); 1690 if (!err) 1691 err = move_addr_to_user(&address, len, usockaddr, 1692 usockaddr_len); 1693 fput_light(sock->file, fput_needed); 1694 } 1695 return err; 1696} 1697 1698/* 1699 * Send a datagram to a given address. We move the address into kernel 1700 * space and check the user space data area is readable before invoking 1701 * the protocol. 1702 */ 1703 1704SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len, 1705 unsigned int, flags, struct sockaddr __user *, addr, 1706 int, addr_len) 1707{ 1708 struct socket *sock; 1709 struct sockaddr_storage address; 1710 int err; 1711 struct msghdr msg; 1712 struct iovec iov; 1713 int fput_needed; 1714 1715 err = import_single_range(WRITE, buff, len, &iov, &msg.msg_iter); 1716 if (unlikely(err)) 1717 return err; 1718 sock = sockfd_lookup_light(fd, &err, &fput_needed); 1719 if (!sock) 1720 goto out; 1721 1722 msg.msg_name = NULL; 1723 msg.msg_control = NULL; 1724 msg.msg_controllen = 0; 1725 msg.msg_namelen = 0; 1726 if (addr) { 1727 err = move_addr_to_kernel(addr, addr_len, &address); 1728 if (err < 0) 1729 goto out_put; 1730 msg.msg_name = (struct sockaddr *)&address; 1731 msg.msg_namelen = addr_len; 1732 } 1733 if (sock->file->f_flags & O_NONBLOCK) 1734 flags |= MSG_DONTWAIT; 1735 msg.msg_flags = flags; 1736 err = sock_sendmsg(sock, &msg); 1737 1738out_put: 1739 fput_light(sock->file, fput_needed); 1740out: 1741 return err; 1742} 1743 1744/* 1745 * Send a datagram down a socket. 1746 */ 1747 1748SYSCALL_DEFINE4(send, int, fd, void __user *, buff, size_t, len, 1749 unsigned int, flags) 1750{ 1751 return sys_sendto(fd, buff, len, flags, NULL, 0); 1752} 1753 1754/* 1755 * Receive a frame from the socket and optionally record the address of the 1756 * sender. We verify the buffers are writable and if needed move the 1757 * sender address from kernel to user space. 1758 */ 1759 1760SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size, 1761 unsigned int, flags, struct sockaddr __user *, addr, 1762 int __user *, addr_len) 1763{ 1764 struct socket *sock; 1765 struct iovec iov; 1766 struct msghdr msg; 1767 struct sockaddr_storage address; 1768 int err, err2; 1769 int fput_needed; 1770 1771 err = import_single_range(READ, ubuf, size, &iov, &msg.msg_iter); 1772 if (unlikely(err)) 1773 return err; 1774 sock = sockfd_lookup_light(fd, &err, &fput_needed); 1775 if (!sock) 1776 goto out; 1777 1778 msg.msg_control = NULL; 1779 msg.msg_controllen = 0; 1780 /* Save some cycles and don't copy the address if not needed */ 1781 msg.msg_name = addr ? (struct sockaddr *)&address : NULL; 1782 /* We assume all kernel code knows the size of sockaddr_storage */ 1783 msg.msg_namelen = 0; 1784 msg.msg_iocb = NULL; 1785 msg.msg_flags = 0; 1786 if (sock->file->f_flags & O_NONBLOCK) 1787 flags |= MSG_DONTWAIT; 1788 err = sock_recvmsg(sock, &msg, flags); 1789 1790 if (err >= 0 && addr != NULL) { 1791 err2 = move_addr_to_user(&address, 1792 msg.msg_namelen, addr, addr_len); 1793 if (err2 < 0) 1794 err = err2; 1795 } 1796 1797 fput_light(sock->file, fput_needed); 1798out: 1799 return err; 1800} 1801 1802/* 1803 * Receive a datagram from a socket. 1804 */ 1805 1806SYSCALL_DEFINE4(recv, int, fd, void __user *, ubuf, size_t, size, 1807 unsigned int, flags) 1808{ 1809 return sys_recvfrom(fd, ubuf, size, flags, NULL, NULL); 1810} 1811 1812/* 1813 * Set a socket option. Because we don't know the option lengths we have 1814 * to pass the user mode parameter for the protocols to sort out. 1815 */ 1816 1817SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname, 1818 char __user *, optval, int, optlen) 1819{ 1820 int err, fput_needed; 1821 struct socket *sock; 1822 1823 if (optlen < 0) 1824 return -EINVAL; 1825 1826 sock = sockfd_lookup_light(fd, &err, &fput_needed); 1827 if (sock != NULL) { 1828 err = security_socket_setsockopt(sock, level, optname); 1829 if (err) 1830 goto out_put; 1831 1832 if (level == SOL_SOCKET) 1833 err = 1834 sock_setsockopt(sock, level, optname, optval, 1835 optlen); 1836 else 1837 err = 1838 sock->ops->setsockopt(sock, level, optname, optval, 1839 optlen); 1840out_put: 1841 fput_light(sock->file, fput_needed); 1842 } 1843 return err; 1844} 1845 1846/* 1847 * Get a socket option. Because we don't know the option lengths we have 1848 * to pass a user mode parameter for the protocols to sort out. 1849 */ 1850 1851SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname, 1852 char __user *, optval, int __user *, optlen) 1853{ 1854 int err, fput_needed; 1855 struct socket *sock; 1856 1857 sock = sockfd_lookup_light(fd, &err, &fput_needed); 1858 if (sock != NULL) { 1859 err = security_socket_getsockopt(sock, level, optname); 1860 if (err) 1861 goto out_put; 1862 1863 if (level == SOL_SOCKET) 1864 err = 1865 sock_getsockopt(sock, level, optname, optval, 1866 optlen); 1867 else 1868 err = 1869 sock->ops->getsockopt(sock, level, optname, optval, 1870 optlen); 1871out_put: 1872 fput_light(sock->file, fput_needed); 1873 } 1874 return err; 1875} 1876 1877/* 1878 * Shutdown a socket. 1879 */ 1880 1881SYSCALL_DEFINE2(shutdown, int, fd, int, how) 1882{ 1883 int err, fput_needed; 1884 struct socket *sock; 1885 1886 sock = sockfd_lookup_light(fd, &err, &fput_needed); 1887 if (sock != NULL) { 1888 err = security_socket_shutdown(sock, how); 1889 if (!err) 1890 err = sock->ops->shutdown(sock, how); 1891 fput_light(sock->file, fput_needed); 1892 } 1893 return err; 1894} 1895 1896/* A couple of helpful macros for getting the address of the 32/64 bit 1897 * fields which are the same type (int / unsigned) on our platforms. 1898 */ 1899#define COMPAT_MSG(msg, member) ((MSG_CMSG_COMPAT & flags) ? &msg##_compat->member : &msg->member) 1900#define COMPAT_NAMELEN(msg) COMPAT_MSG(msg, msg_namelen) 1901#define COMPAT_FLAGS(msg) COMPAT_MSG(msg, msg_flags) 1902 1903struct used_address { 1904 struct sockaddr_storage name; 1905 unsigned int name_len; 1906}; 1907 1908static int copy_msghdr_from_user(struct msghdr *kmsg, 1909 struct user_msghdr __user *umsg, 1910 struct sockaddr __user **save_addr, 1911 struct iovec **iov) 1912{ 1913 struct sockaddr __user *uaddr; 1914 struct iovec __user *uiov; 1915 size_t nr_segs; 1916 ssize_t err; 1917 1918 if (!access_ok(VERIFY_READ, umsg, sizeof(*umsg)) || 1919 __get_user(uaddr, &umsg->msg_name) || 1920 __get_user(kmsg->msg_namelen, &umsg->msg_namelen) || 1921 __get_user(uiov, &umsg->msg_iov) || 1922 __get_user(nr_segs, &umsg->msg_iovlen) || 1923 __get_user(kmsg->msg_control, &umsg->msg_control) || 1924 __get_user(kmsg->msg_controllen, &umsg->msg_controllen) || 1925 __get_user(kmsg->msg_flags, &umsg->msg_flags)) 1926 return -EFAULT; 1927 1928 if (!uaddr) 1929 kmsg->msg_namelen = 0; 1930 1931 if (kmsg->msg_namelen < 0) 1932 return -EINVAL; 1933 1934 if (kmsg->msg_namelen > sizeof(struct sockaddr_storage)) 1935 kmsg->msg_namelen = sizeof(struct sockaddr_storage); 1936 1937 if (save_addr) 1938 *save_addr = uaddr; 1939 1940 if (uaddr && kmsg->msg_namelen) { 1941 if (!save_addr) { 1942 err = move_addr_to_kernel(uaddr, kmsg->msg_namelen, 1943 kmsg->msg_name); 1944 if (err < 0) 1945 return err; 1946 } 1947 } else { 1948 kmsg->msg_name = NULL; 1949 kmsg->msg_namelen = 0; 1950 } 1951 1952 if (nr_segs > UIO_MAXIOV) 1953 return -EMSGSIZE; 1954 1955 kmsg->msg_iocb = NULL; 1956 1957 return import_iovec(save_addr ? READ : WRITE, uiov, nr_segs, 1958 UIO_FASTIOV, iov, &kmsg->msg_iter); 1959} 1960 1961static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg, 1962 struct msghdr *msg_sys, unsigned int flags, 1963 struct used_address *used_address, 1964 unsigned int allowed_msghdr_flags) 1965{ 1966 struct compat_msghdr __user *msg_compat = 1967 (struct compat_msghdr __user *)msg; 1968 struct sockaddr_storage address; 1969 struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; 1970 unsigned char ctl[sizeof(struct cmsghdr) + 20] 1971 __aligned(sizeof(__kernel_size_t)); 1972 /* 20 is size of ipv6_pktinfo */ 1973 unsigned char *ctl_buf = ctl; 1974 int ctl_len; 1975 ssize_t err; 1976 1977 msg_sys->msg_name = &address; 1978 1979 if (MSG_CMSG_COMPAT & flags) 1980 err = get_compat_msghdr(msg_sys, msg_compat, NULL, &iov); 1981 else 1982 err = copy_msghdr_from_user(msg_sys, msg, NULL, &iov); 1983 if (err < 0) 1984 return err; 1985 1986 err = -ENOBUFS; 1987 1988 if (msg_sys->msg_controllen > INT_MAX) 1989 goto out_freeiov; 1990 flags |= (msg_sys->msg_flags & allowed_msghdr_flags); 1991 ctl_len = msg_sys->msg_controllen; 1992 if ((MSG_CMSG_COMPAT & flags) && ctl_len) { 1993 err =…
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