net/compat.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * 32bit Socket syscall emulation. Based on arch/sparc64/kernel/sys_sparc32.c.
   4  *
   5  * Copyright (C) 2000           VA Linux Co
   6  * Copyright (C) 2000           Don Dugger <n0ano@valinux.com>
   7  * Copyright (C) 1999           Arun Sharma <arun.sharma@intel.com>
   8  * Copyright (C) 1997,1998      Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   9  * Copyright (C) 1997           David S. Miller (davem@caip.rutgers.edu)
  10  * Copyright (C) 2000           Hewlett-Packard Co.
  11  * Copyright (C) 2000           David Mosberger-Tang <davidm@hpl.hp.com>
  12  * Copyright (C) 2000,2001      Andi Kleen, SuSE Labs
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/gfp.h>
  17 #include <linux/fs.h>
  18 #include <linux/types.h>
  19 #include <linux/file.h>
  20 #include <linux/icmpv6.h>
  21 #include <linux/socket.h>
  22 #include <linux/syscalls.h>
  23 #include <linux/filter.h>
  24 #include <linux/compat.h>
  25 #include <linux/security.h>
  26 #include <linux/audit.h>
  27 #include <linux/export.h>
  28
  29 #include <net/scm.h>
  30 #include <net/sock.h>
  31 #include <net/ip.h>
  32 #include <net/ipv6.h>
  33 #include <linux/uaccess.h>
  34 #include <net/compat.h>
  35
  36 int __get_compat_msghdr(struct msghdr *kmsg,
  37                         struct compat_msghdr __user *umsg,
  38                         struct sockaddr __user **save_addr,
  39                         compat_uptr_t *ptr, compat_size_t *len)
  40 {
  41         struct compat_msghdr msg;
  42         ssize_t err;
  43
  44         if (copy_from_user(&msg, umsg, sizeof(*umsg)))
  45                 return -EFAULT;
  46
  47         kmsg->msg_flags = msg.msg_flags;
  48         kmsg->msg_namelen = msg.msg_namelen;
  49
  50         if (!msg.msg_name)
  51                 kmsg->msg_namelen = 0;
  52
  53         if (kmsg->msg_namelen < 0)
  54                 return -EINVAL;
  55
  56         if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
  57                 kmsg->msg_namelen = sizeof(struct sockaddr_storage);
  58
  59         kmsg->msg_control_is_user = true;
  60         kmsg->msg_control_user = compat_ptr(msg.msg_control);
  61         kmsg->msg_controllen = msg.msg_controllen;
  62
  63         if (save_addr)
  64                 *save_addr = compat_ptr(msg.msg_name);
  65
  66         if (msg.msg_name && kmsg->msg_namelen) {
  67                 if (!save_addr) {
  68                         err = move_addr_to_kernel(compat_ptr(msg.msg_name),
  69                                                   kmsg->msg_namelen,
  70                                                   kmsg->msg_name);
  71                         if (err < 0)
  72                                 return err;
  73                 }
  74         } else {
  75                 kmsg->msg_name = NULL;
  76                 kmsg->msg_namelen = 0;
  77         }
  78
  79         if (msg.msg_iovlen > UIO_MAXIOV)
  80                 return -EMSGSIZE;
  81
  82         kmsg->msg_iocb = NULL;
  83         *ptr = msg.msg_iov;
  84         *len = msg.msg_iovlen;
  85         return 0;
  86 }
  87
  88 int get_compat_msghdr(struct msghdr *kmsg,
  89                       struct compat_msghdr __user *umsg,
  90                       struct sockaddr __user **save_addr,
  91                       struct iovec **iov)
  92 {
  93         compat_uptr_t ptr;
  94         compat_size_t len;
  95         ssize_t err;
  96
  97         err = __get_compat_msghdr(kmsg, umsg, save_addr, &ptr, &len);
  98         if (err)
  99                 return err;
 100
 101         err = compat_import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr),
 102                                    len, UIO_FASTIOV, iov, &kmsg->msg_iter);
 103         return err < 0 ? err : 0;
 104 }
 105
 106 /* Bleech... */
 107 #define CMSG_COMPAT_ALIGN(len)  ALIGN((len), sizeof(s32))
 108
 109 #define CMSG_COMPAT_DATA(cmsg)                          \
 110         ((void __user *)((char __user *)(cmsg) + sizeof(struct compat_cmsghdr)))
 111 #define CMSG_COMPAT_SPACE(len)                          \
 112         (sizeof(struct compat_cmsghdr) + CMSG_COMPAT_ALIGN(len))
 113 #define CMSG_COMPAT_LEN(len)                            \
 114         (sizeof(struct compat_cmsghdr) + (len))
 115
 116 #define CMSG_COMPAT_FIRSTHDR(msg)                       \
 117         (((msg)->msg_controllen) >= sizeof(struct compat_cmsghdr) ?     \
 118          (struct compat_cmsghdr __user *)((msg)->msg_control) :         \
 119          (struct compat_cmsghdr __user *)NULL)
 120
 121 #define CMSG_COMPAT_OK(ucmlen, ucmsg, mhdr) \
 122         ((ucmlen) >= sizeof(struct compat_cmsghdr) && \
 123          (ucmlen) <= (unsigned long) \
 124          ((mhdr)->msg_controllen - \
 125           ((char __user *)(ucmsg) - (char __user *)(mhdr)->msg_control_user)))
 126
 127 static inline struct compat_cmsghdr __user *cmsg_compat_nxthdr(struct msghdr *msg,
 128                 struct compat_cmsghdr __user *cmsg, int cmsg_len)
 129 {
 130         char __user *ptr = (char __user *)cmsg + CMSG_COMPAT_ALIGN(cmsg_len);
 131         if ((unsigned long)(ptr + 1 - (char __user *)msg->msg_control) >
 132                         msg->msg_controllen)
 133                 return NULL;
 134         return (struct compat_cmsghdr __user *)ptr;
 135 }
 136
 137 /* There is a lot of hair here because the alignment rules (and
 138  * thus placement) of cmsg headers and length are different for
 139  * 32-bit apps.  -DaveM
 140  */
 141 int cmsghdr_from_user_compat_to_kern(struct msghdr *kmsg, struct sock *sk,
 142                                unsigned char *stackbuf, int stackbuf_size)
 143 {
 144         struct compat_cmsghdr __user *ucmsg;
 145         struct cmsghdr *kcmsg, *kcmsg_base;
 146         compat_size_t ucmlen;
 147         __kernel_size_t kcmlen, tmp;
 148         int err = -EFAULT;
 149
 150         BUILD_BUG_ON(sizeof(struct compat_cmsghdr) !=
 151                      CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)));
 152
 153         kcmlen = 0;
 154         kcmsg_base = kcmsg = (struct cmsghdr *)stackbuf;
 155         ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
 156         while (ucmsg != NULL) {
 157                 if (get_user(ucmlen, &ucmsg->cmsg_len))
 158                         return -EFAULT;
 159
 160                 /* Catch bogons. */
 161                 if (!CMSG_COMPAT_OK(ucmlen, ucmsg, kmsg))
 162                         return -EINVAL;
 163
 164                 tmp = ((ucmlen - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
 165                 tmp = CMSG_ALIGN(tmp);
 166                 kcmlen += tmp;
 167                 ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
 168         }
 169         if (kcmlen == 0)
 170                 return -EINVAL;
 171
 172         /* The kcmlen holds the 64-bit version of the control length.
 173          * It may not be modified as we do not stick it into the kmsg
 174          * until we have successfully copied over all of the data
 175          * from the user.
 176          */
 177         if (kcmlen > stackbuf_size)
 178                 kcmsg_base = kcmsg = sock_kmalloc(sk, kcmlen, GFP_KERNEL);
 179         if (kcmsg == NULL)
 180                 return -ENOBUFS;
 181
 182         /* Now copy them over neatly. */
 183         memset(kcmsg, 0, kcmlen);
 184         ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
 185         while (ucmsg != NULL) {
 186                 struct compat_cmsghdr cmsg;
 187                 if (copy_from_user(&cmsg, ucmsg, sizeof(cmsg)))
 188                         goto Efault;
 189                 if (!CMSG_COMPAT_OK(cmsg.cmsg_len, ucmsg, kmsg))
 190                         goto Einval;
 191                 tmp = ((cmsg.cmsg_len - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
 192                 if ((char *)kcmsg_base + kcmlen - (char *)kcmsg < CMSG_ALIGN(tmp))
 193                         goto Einval;
 194                 kcmsg->cmsg_len = tmp;
 195                 kcmsg->cmsg_level = cmsg.cmsg_level;
 196                 kcmsg->cmsg_type = cmsg.cmsg_type;
 197                 tmp = CMSG_ALIGN(tmp);
 198                 if (copy_from_user(CMSG_DATA(kcmsg),
 199                                    CMSG_COMPAT_DATA(ucmsg),
 200                                    (cmsg.cmsg_len - sizeof(*ucmsg))))
 201                         goto Efault;
 202
 203                 /* Advance. */
 204                 kcmsg = (struct cmsghdr *)((char *)kcmsg + tmp);
 205                 ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
 206         }
 207
 208         /*
 209          * check the length of messages copied in is the same as the
 210          * what we get from the first loop
 211          */
 212         if ((char *)kcmsg - (char *)kcmsg_base != kcmlen)
 213                 goto Einval;
 214
 215         /* Ok, looks like we made it.  Hook it up and return success. */
 216         kmsg->msg_control = kcmsg_base;
 217         kmsg->msg_controllen = kcmlen;
 218         return 0;
 219
 220 Einval:
 221         err = -EINVAL;
 222 Efault:
 223         if (kcmsg_base != (struct cmsghdr *)stackbuf)
 224                 sock_kfree_s(sk, kcmsg_base, kcmlen);
 225         return err;
 226 }
 227
 228 int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *data)
 229 {
 230         struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
 231         struct compat_cmsghdr cmhdr;
 232         struct old_timeval32 ctv;
 233         struct old_timespec32 cts[3];
 234         int cmlen;
 235
 236         if (cm == NULL || kmsg->msg_controllen < sizeof(*cm)) {
 237                 kmsg->msg_flags |= MSG_CTRUNC;
 238                 return 0; /* XXX: return error? check spec. */
 239         }
 240
 241         if (!COMPAT_USE_64BIT_TIME) {
 242                 if (level == SOL_SOCKET && type == SO_TIMESTAMP_OLD) {
 243                         struct __kernel_old_timeval *tv = (struct __kernel_old_timeval *)data;
 244                         ctv.tv_sec = tv->tv_sec;
 245                         ctv.tv_usec = tv->tv_usec;
 246                         data = &ctv;
 247                         len = sizeof(ctv);
 248                 }
 249                 if (level == SOL_SOCKET &&
 250                     (type == SO_TIMESTAMPNS_OLD || type == SO_TIMESTAMPING_OLD)) {
 251                         int count = type == SO_TIMESTAMPNS_OLD ? 1 : 3;
 252                         int i;
 253                         struct __kernel_old_timespec *ts = data;
 254                         for (i = 0; i < count; i++) {
 255                                 cts[i].tv_sec = ts[i].tv_sec;
 256                                 cts[i].tv_nsec = ts[i].tv_nsec;
 257                         }
 258                         data = &cts;
 259                         len = sizeof(cts[0]) * count;
 260                 }
 261         }
 262
 263         cmlen = CMSG_COMPAT_LEN(len);
 264         if (kmsg->msg_controllen < cmlen) {
 265                 kmsg->msg_flags |= MSG_CTRUNC;
 266                 cmlen = kmsg->msg_controllen;
 267         }
 268         cmhdr.cmsg_level = level;
 269         cmhdr.cmsg_type = type;
 270         cmhdr.cmsg_len = cmlen;
 271
 272         if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
 273                 return -EFAULT;
 274         if (copy_to_user(CMSG_COMPAT_DATA(cm), data, cmlen - sizeof(struct compat_cmsghdr)))
 275                 return -EFAULT;
 276         cmlen = CMSG_COMPAT_SPACE(len);
 277         if (kmsg->msg_controllen < cmlen)
 278                 cmlen = kmsg->msg_controllen;
 279         kmsg->msg_control += cmlen;
 280         kmsg->msg_controllen -= cmlen;
 281         return 0;
 282 }
 283
 284 void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
 285 {
 286         struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
 287         int fdmax = (kmsg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
 288         int fdnum = scm->fp->count;
 289         struct file **fp = scm->fp->fp;
 290         int __user *cmfptr;
 291         int err = 0, i;
 292
 293         if (fdnum < fdmax)
 294                 fdmax = fdnum;
 295
 296         for (i = 0, cmfptr = (int __user *) CMSG_COMPAT_DATA(cm); i < fdmax; i++, cmfptr++) {
 297                 int new_fd;
 298                 err = security_file_receive(fp[i]);
 299                 if (err)
 300                         break;
 301                 err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & kmsg->msg_flags
 302                                           ? O_CLOEXEC : 0);
 303                 if (err < 0)
 304                         break;
 305                 new_fd = err;
 306                 err = put_user(new_fd, cmfptr);
 307                 if (err) {
 308                         put_unused_fd(new_fd);
 309                         break;
 310                 }
 311                 /* Bump the usage count and install the file. */
 312                 fd_install(new_fd, get_file(fp[i]));
 313         }
 314
 315         if (i > 0) {
 316                 int cmlen = CMSG_COMPAT_LEN(i * sizeof(int));
 317                 err = put_user(SOL_SOCKET, &cm->cmsg_level);
 318                 if (!err)
 319                         err = put_user(SCM_RIGHTS, &cm->cmsg_type);
 320                 if (!err)
 321                         err = put_user(cmlen, &cm->cmsg_len);
 322                 if (!err) {
 323                         cmlen = CMSG_COMPAT_SPACE(i * sizeof(int));
 324                         kmsg->msg_control += cmlen;
 325                         kmsg->msg_controllen -= cmlen;
 326                 }
 327         }
 328         if (i < fdnum)
 329                 kmsg->msg_flags |= MSG_CTRUNC;
 330
 331         /*
 332          * All of the files that fit in the message have had their
 333          * usage counts incremented, so we just free the list.
 334          */
 335         __scm_destroy(scm);
 336 }
 337
 338 /* allocate a 64-bit sock_fprog on the user stack for duration of syscall. */
 339 struct sock_fprog __user *get_compat_bpf_fprog(char __user *optval)
 340 {
 341         struct compat_sock_fprog __user *fprog32 = (struct compat_sock_fprog __user *)optval;
 342         struct sock_fprog __user *kfprog = compat_alloc_user_space(sizeof(struct sock_fprog));
 343         struct compat_sock_fprog f32;
 344         struct sock_fprog f;
 345
 346         if (copy_from_user(&f32, fprog32, sizeof(*fprog32)))
 347                 return NULL;
 348         memset(&f, 0, sizeof(f));
 349         f.len = f32.len;
 350         f.filter = compat_ptr(f32.filter);
 351         if (copy_to_user(kfprog, &f, sizeof(struct sock_fprog)))
 352                 return NULL;
 353
 354         return kfprog;
 355 }
 356 EXPORT_SYMBOL_GPL(get_compat_bpf_fprog);
 357
 358 static int do_set_attach_filter(struct socket *sock, int level, int optname,
 359                                 char __user *optval, unsigned int optlen)
 360 {
 361         struct sock_fprog __user *kfprog;
 362
 363         kfprog = get_compat_bpf_fprog(optval);
 364         if (!kfprog)
 365                 return -EFAULT;
 366
 367         return sock_setsockopt(sock, level, optname, (char __user *)kfprog,
 368                               sizeof(struct sock_fprog));
 369 }
 370
 371 static int compat_sock_setsockopt(struct socket *sock, int level, int optname,
 372                                 char __user *optval, unsigned int optlen)
 373 {
 374         if (optname == SO_ATTACH_FILTER ||
 375             optname == SO_ATTACH_REUSEPORT_CBPF)
 376                 return do_set_attach_filter(sock, level, optname,
 377                                             optval, optlen);
 378         return sock_setsockopt(sock, level, optname, optval, optlen);
 379 }
 380
 381 static int __compat_sys_setsockopt(int fd, int level, int optname,
 382                                    char __user *optval, unsigned int optlen)
 383 {
 384         int err;
 385         struct socket *sock;
 386
 387         if (optlen > INT_MAX)
 388                 return -EINVAL;
 389
 390         sock = sockfd_lookup(fd, &err);
 391         if (sock) {
 392                 err = security_socket_setsockopt(sock, level, optname);
 393                 if (err) {
 394                         sockfd_put(sock);
 395                         return err;
 396                 }
 397
 398                 if (level == SOL_SOCKET)
 399                         err = compat_sock_setsockopt(sock, level,
 400                                         optname, optval, optlen);
 401                 else if (sock->ops->compat_setsockopt)
 402                         err = sock->ops->compat_setsockopt(sock, level,
 403                                         optname, optval, optlen);
 404                 else
 405                         err = sock->ops->setsockopt(sock, level,
 406                                         optname, optval, optlen);
 407                 sockfd_put(sock);
 408         }
 409         return err;
 410 }
 411
 412 COMPAT_SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
 413                        char __user *, optval, unsigned int, optlen)
 414 {
 415         return __compat_sys_setsockopt(fd, level, optname, optval, optlen);
 416 }
 417
 418 static int __compat_sys_getsockopt(int fd, int level, int optname,
 419                                    char __user *optval,
 420                                    int __user *optlen)
 421 {
 422         int err;
 423         struct socket *sock = sockfd_lookup(fd, &err);
 424
 425         if (sock) {
 426                 err = security_socket_getsockopt(sock, level, optname);
 427                 if (err) {
 428                         sockfd_put(sock);
 429                         return err;
 430                 }
 431
 432                 if (level == SOL_SOCKET)
 433                         err = sock_getsockopt(sock, level,
 434                                         optname, optval, optlen);
 435                 else if (sock->ops->compat_getsockopt)
 436                         err = sock->ops->compat_getsockopt(sock, level,
 437                                         optname, optval, optlen);
 438                 else
 439                         err = sock->ops->getsockopt(sock, level,
 440                                         optname, optval, optlen);
 441                 sockfd_put(sock);
 442         }
 443         return err;
 444 }
 445
 446 COMPAT_SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
 447                        char __user *, optval, int __user *, optlen)
 448 {
 449         return __compat_sys_getsockopt(fd, level, optname, optval, optlen);
 450 }
 451
 452 /* Argument list sizes for compat_sys_socketcall */
 453 #define AL(x) ((x) * sizeof(u32))
 454 static unsigned char nas[21] = {
 455         AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
 456         AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
 457         AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
 458         AL(4), AL(5), AL(4)
 459 };
 460 #undef AL
 461
 462 static inline long __compat_sys_sendmsg(int fd,
 463                                         struct compat_msghdr __user *msg,
 464                                         unsigned int flags)
 465 {
 466         return __sys_sendmsg(fd, (struct user_msghdr __user *)msg,
 467                              flags | MSG_CMSG_COMPAT, false);
 468 }
 469
 470 COMPAT_SYSCALL_DEFINE3(sendmsg, int, fd, struct compat_msghdr __user *, msg,
 471                        unsigned int, flags)
 472 {
 473         return __compat_sys_sendmsg(fd, msg, flags);
 474 }
 475
 476 static inline long __compat_sys_sendmmsg(int fd,
 477                                          struct compat_mmsghdr __user *mmsg,
 478                                          unsigned int vlen, unsigned int flags)
 479 {
 480         return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
 481                               flags | MSG_CMSG_COMPAT, false);
 482 }
 483
 484 COMPAT_SYSCALL_DEFINE4(sendmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
 485                        unsigned int, vlen, unsigned int, flags)
 486 {
 487         return __compat_sys_sendmmsg(fd, mmsg, vlen, flags);
 488 }
 489
 490 static inline long __compat_sys_recvmsg(int fd,
 491                                         struct compat_msghdr __user *msg,
 492                                         unsigned int flags)
 493 {
 494         return __sys_recvmsg(fd, (struct user_msghdr __user *)msg,
 495                              flags | MSG_CMSG_COMPAT, false);
 496 }
 497
 498 COMPAT_SYSCALL_DEFINE3(recvmsg, int, fd, struct compat_msghdr __user *, msg,
 499                        unsigned int, flags)
 500 {
 501         return __compat_sys_recvmsg(fd, msg, flags);
 502 }
 503
 504 static inline long __compat_sys_recvfrom(int fd, void __user *buf,
 505                                          compat_size_t len, unsigned int flags,
 506                                          struct sockaddr __user *addr,
 507                                          int __user *addrlen)
 508 {
 509         return __sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, addr,
 510                               addrlen);
 511 }
 512
 513 COMPAT_SYSCALL_DEFINE4(recv, int, fd, void __user *, buf, compat_size_t, len, unsigned int, flags)
 514 {
 515         return __compat_sys_recvfrom(fd, buf, len, flags, NULL, NULL);
 516 }
 517
 518 COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len,
 519                        unsigned int, flags, struct sockaddr __user *, addr,
 520                        int __user *, addrlen)
 521 {
 522         return __compat_sys_recvfrom(fd, buf, len, flags, addr, addrlen);
 523 }
 524
 525 COMPAT_SYSCALL_DEFINE5(recvmmsg_time64, int, fd, struct compat_mmsghdr __user *, mmsg,
 526                        unsigned int, vlen, unsigned int, flags,
 527                        struct __kernel_timespec __user *, timeout)
 528 {
 529         return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
 530                               flags | MSG_CMSG_COMPAT, timeout, NULL);
 531 }
 532
 533 #ifdef CONFIG_COMPAT_32BIT_TIME
 534 COMPAT_SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct compat_mmsghdr __user *, mmsg,
 535                        unsigned int, vlen, unsigned int, flags,
 536                        struct old_timespec32 __user *, timeout)
 537 {
 538         return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
 539                               flags | MSG_CMSG_COMPAT, NULL, timeout);
 540 }
 541 #endif
 542
 543 COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
 544 {
 545         u32 a[AUDITSC_ARGS];
 546         unsigned int len;
 547         u32 a0, a1;
 548         int ret;
 549
 550         if (call < SYS_SOCKET || call > SYS_SENDMMSG)
 551                 return -EINVAL;
 552         len = nas[call];
 553         if (len > sizeof(a))
 554                 return -EINVAL;
 555
 556         if (copy_from_user(a, args, len))
 557                 return -EFAULT;
 558
 559         ret = audit_socketcall_compat(len / sizeof(a[0]), a);
 560         if (ret)
 561                 return ret;
 562
 563         a0 = a[0];
 564         a1 = a[1];
 565
 566         switch (call) {
 567         case SYS_SOCKET:
 568                 ret = __sys_socket(a0, a1, a[2]);
 569                 break;
 570         case SYS_BIND:
 571                 ret = __sys_bind(a0, compat_ptr(a1), a[2]);
 572                 break;
 573         case SYS_CONNECT:
 574                 ret = __sys_connect(a0, compat_ptr(a1), a[2]);
 575                 break;
 576         case SYS_LISTEN:
 577                 ret = __sys_listen(a0, a1);
 578                 break;
 579         case SYS_ACCEPT:
 580                 ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
 581                 break;
 582         case SYS_GETSOCKNAME:
 583                 ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
 584                 break;
 585         case SYS_GETPEERNAME:
 586                 ret = __sys_getpeername(a0, compat_ptr(a1), compat_ptr(a[2]));
 587                 break;
 588         case SYS_SOCKETPAIR:
 589                 ret = __sys_socketpair(a0, a1, a[2], compat_ptr(a[3]));
 590                 break;
 591         case SYS_SEND:
 592                 ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3], NULL, 0);
 593                 break;
 594         case SYS_SENDTO:
 595                 ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3],
 596                                    compat_ptr(a[4]), a[5]);
 597                 break;
 598         case SYS_RECV:
 599                 ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
 600                                             NULL, NULL);
 601                 break;
 602         case SYS_RECVFROM:
 603                 ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
 604                                             compat_ptr(a[4]),
 605                                             compat_ptr(a[5]));
 606                 break;
 607         case SYS_SHUTDOWN:
 608                 ret = __sys_shutdown(a0, a1);
 609                 break;
 610         case SYS_SETSOCKOPT:
 611                 ret = __compat_sys_setsockopt(a0, a1, a[2],
 612                                               compat_ptr(a[3]), a[4]);
 613                 break;
 614         case SYS_GETSOCKOPT:
 615                 ret = __compat_sys_getsockopt(a0, a1, a[2],
 616                                               compat_ptr(a[3]),
 617                                               compat_ptr(a[4]));
 618                 break;
 619         case SYS_SENDMSG:
 620                 ret = __compat_sys_sendmsg(a0, compat_ptr(a1), a[2]);
 621                 break;
 622         case SYS_SENDMMSG:
 623                 ret = __compat_sys_sendmmsg(a0, compat_ptr(a1), a[2], a[3]);
 624                 break;
 625         case SYS_RECVMSG:
 626                 ret = __compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
 627                 break;
 628         case SYS_RECVMMSG:
 629                 ret = __sys_recvmmsg(a0, compat_ptr(a1), a[2],
 630                                      a[3] | MSG_CMSG_COMPAT, NULL,
 631                                      compat_ptr(a[4]));
 632                 break;
 633         case SYS_ACCEPT4:
 634                 ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]);
 635                 break;
 636         default:
 637                 ret = -EINVAL;
 638                 break;
 639         }
 640         return ret;
 641 }