arch/um/drivers/vector_user.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   4  */
   5
   6 #include <stdio.h>
   7 #include <unistd.h>
   8 #include <stdarg.h>
   9 #include <errno.h>
  10 #include <stddef.h>
  11 #include <string.h>
  12 #include <sys/ioctl.h>
  13 #include <net/if.h>
  14 #include <linux/if_tun.h>
  15 #include <arpa/inet.h>
  16 #include <sys/types.h>
  17 #include <sys/stat.h>
  18 #include <fcntl.h>
  19 #include <sys/socket.h>
  20 #include <sys/un.h>
  21 #include <net/ethernet.h>
  22 #include <netinet/ip.h>
  23 #include <netinet/ether.h>
  24 #include <linux/if_ether.h>
  25 #include <linux/if_packet.h>
  26 #include <sys/wait.h>
  27 #include <sys/uio.h>
  28 #include <linux/virtio_net.h>
  29 #include <netdb.h>
  30 #include <stdlib.h>
  31 #include <os.h>
  32 #include <um_malloc.h>
  33 #include "vector_user.h"
  34
  35 #define ID_GRE 0
  36 #define ID_L2TPV3 1
  37 #define ID_BESS 2
  38 #define ID_MAX 2
  39
  40 #define TOKEN_IFNAME "ifname"
  41
  42 #define TRANS_RAW "raw"
  43 #define TRANS_RAW_LEN strlen(TRANS_RAW)
  44
  45 #define VNET_HDR_FAIL "could not enable vnet headers on fd %d"
  46 #define TUN_GET_F_FAIL "tapraw: TUNGETFEATURES failed: %s"
  47 #define L2TPV3_BIND_FAIL "l2tpv3_open : could not bind socket err=%i"
  48 #define UNIX_BIND_FAIL "unix_open : could not bind socket err=%i"
  49 #define BPF_ATTACH_FAIL "Failed to attach filter size %d prog %px to %d, err %d\n"
  50 #define BPF_DETACH_FAIL "Failed to detach filter size %d prog %px to %d, err %d\n"
  51
  52 #define MAX_UN_LEN 107
  53
  54 /* This is very ugly and brute force lookup, but it is done
  55  * only once at initialization so not worth doing hashes or
  56  * anything more intelligent
  57  */
  58
  59 char *uml_vector_fetch_arg(struct arglist *ifspec, char *token)
  60 {
  61         int i;
  62
  63         for (i = 0; i < ifspec->numargs; i++) {
  64                 if (strcmp(ifspec->tokens[i], token) == 0)
  65                         return ifspec->values[i];
  66         }
  67         return NULL;
  68
  69 }
  70
  71 struct arglist *uml_parse_vector_ifspec(char *arg)
  72 {
  73         struct arglist *result;
  74         int pos, len;
  75         bool parsing_token = true, next_starts = true;
  76
  77         if (arg == NULL)
  78                 return NULL;
  79         result = uml_kmalloc(sizeof(struct arglist), UM_GFP_KERNEL);
  80         if (result == NULL)
  81                 return NULL;
  82         result->numargs = 0;
  83         len = strlen(arg);
  84         for (pos = 0; pos < len; pos++) {
  85                 if (next_starts) {
  86                         if (parsing_token) {
  87                                 result->tokens[result->numargs] = arg + pos;
  88                         } else {
  89                                 result->values[result->numargs] = arg + pos;
  90                                 result->numargs++;
  91                         }
  92                         next_starts = false;
  93                 }
  94                 if (*(arg + pos) == '=') {
  95                         if (parsing_token)
  96                                 parsing_token = false;
  97                         else
  98                                 goto cleanup;
  99                         next_starts = true;
 100                         (*(arg + pos)) = '\0';
 101                 }
 102                 if (*(arg + pos) == ',') {
 103                         parsing_token = true;
 104                         next_starts = true;
 105                         (*(arg + pos)) = '\0';
 106                 }
 107         }
 108         return result;
 109 cleanup:
 110         printk(UM_KERN_ERR "vector_setup - Couldn't parse '%s'\n", arg);
 111         kfree(result);
 112         return NULL;
 113 }
 114
 115 /*
 116  * Socket/FD configuration functions. These return an structure
 117  * of rx and tx descriptors to cover cases where these are not
 118  * the same (f.e. read via raw socket and write via tap).
 119  */
 120
 121 #define PATH_NET_TUN "/dev/net/tun"
 122
 123
 124 static int create_tap_fd(char *iface)
 125 {
 126         struct ifreq ifr;
 127         int fd = -1;
 128         int err = -ENOMEM, offload;
 129
 130         fd = open(PATH_NET_TUN, O_RDWR);
 131         if (fd < 0) {
 132                 printk(UM_KERN_ERR "uml_tap: failed to open tun device\n");
 133                 goto tap_fd_cleanup;
 134         }
 135         memset(&ifr, 0, sizeof(ifr));
 136         ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR;
 137         strncpy((char *)&ifr.ifr_name, iface, sizeof(ifr.ifr_name) - 1);
 138
 139         err = ioctl(fd, TUNSETIFF, (void *) &ifr);
 140         if (err != 0) {
 141                 printk(UM_KERN_ERR "uml_tap: failed to select tap interface\n");
 142                 goto tap_fd_cleanup;
 143         }
 144
 145         offload = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6;
 146         ioctl(fd, TUNSETOFFLOAD, offload);
 147         return fd;
 148 tap_fd_cleanup:
 149         if (fd >= 0)
 150                 os_close_file(fd);
 151         return err;
 152 }
 153
 154 static int create_raw_fd(char *iface, int flags, int proto)
 155 {
 156         struct ifreq ifr;
 157         int fd = -1;
 158         struct sockaddr_ll sock;
 159         int err = -ENOMEM;
 160
 161         fd = socket(AF_PACKET, SOCK_RAW, flags);
 162         if (fd == -1) {
 163                 err = -errno;
 164                 goto raw_fd_cleanup;
 165         }
 166         memset(&ifr, 0, sizeof(ifr));
 167         strncpy((char *)&ifr.ifr_name, iface, sizeof(ifr.ifr_name) - 1);
 168         if (ioctl(fd, SIOCGIFINDEX, (void *) &ifr) < 0) {
 169                 err = -errno;
 170                 goto raw_fd_cleanup;
 171         }
 172
 173         sock.sll_family = AF_PACKET;
 174         sock.sll_protocol = htons(proto);
 175         sock.sll_ifindex = ifr.ifr_ifindex;
 176
 177         if (bind(fd,
 178                 (struct sockaddr *) &sock, sizeof(struct sockaddr_ll)) < 0) {
 179                 err = -errno;
 180                 goto raw_fd_cleanup;
 181         }
 182         return fd;
 183 raw_fd_cleanup:
 184         printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);
 185         if (fd >= 0)
 186                 os_close_file(fd);
 187         return err;
 188 }
 189
 190 static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 191 {
 192         int fd = -1;
 193         char *iface;
 194         struct vector_fds *result = NULL;
 195
 196         iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
 197         if (iface == NULL) {
 198                 printk(UM_KERN_ERR "uml_tap: failed to parse interface spec\n");
 199                 goto tap_cleanup;
 200         }
 201
 202         result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
 203         if (result == NULL) {
 204                 printk(UM_KERN_ERR "uml_tap: failed to allocate file descriptors\n");
 205                 goto tap_cleanup;
 206         }
 207         result->rx_fd = -1;
 208         result->tx_fd = -1;
 209         result->remote_addr = NULL;
 210         result->remote_addr_size = 0;
 211
 212         /* TAP */
 213
 214         fd = create_tap_fd(iface);
 215         if (fd < 0) {
 216                 printk(UM_KERN_ERR "uml_tap: failed to create tun interface\n");
 217                 goto tap_cleanup;
 218         }
 219         result->tx_fd = fd;
 220         result->rx_fd = fd;
 221         return result;
 222 tap_cleanup:
 223         printk(UM_KERN_ERR "user_init_tap: init failed, error %d", fd);
 224         kfree(result);
 225         return NULL;
 226 }
 227
 228 static struct vector_fds *user_init_hybrid_fds(struct arglist *ifspec)
 229 {
 230         char *iface;
 231         struct vector_fds *result = NULL;
 232
 233         iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
 234         if (iface == NULL) {
 235                 printk(UM_KERN_ERR "uml_tap: failed to parse interface spec\n");
 236                 goto hybrid_cleanup;
 237         }
 238
 239         result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
 240         if (result == NULL) {
 241                 printk(UM_KERN_ERR "uml_tap: failed to allocate file descriptors\n");
 242                 goto hybrid_cleanup;
 243         }
 244         result->rx_fd = -1;
 245         result->tx_fd = -1;
 246         result->remote_addr = NULL;
 247         result->remote_addr_size = 0;
 248
 249         /* TAP */
 250
 251         result->tx_fd = create_tap_fd(iface);
 252         if (result->tx_fd < 0) {
 253                 printk(UM_KERN_ERR "uml_tap: failed to create tun interface: %i\n", result->tx_fd);
 254                 goto hybrid_cleanup;
 255         }
 256
 257         /* RAW */
 258
 259         result->rx_fd = create_raw_fd(iface, ETH_P_ALL, ETH_P_ALL);
 260         if (result->rx_fd == -1) {
 261                 printk(UM_KERN_ERR
 262                         "uml_tap: failed to create paired raw socket: %i\n", result->rx_fd);
 263                 goto hybrid_cleanup;
 264         }
 265         return result;
 266 hybrid_cleanup:
 267         printk(UM_KERN_ERR "user_init_hybrid: init failed");
 268         kfree(result);
 269         return NULL;
 270 }
 271
 272 static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id)
 273 {
 274         int fd = -1;
 275         int socktype;
 276         char *src, *dst;
 277         struct vector_fds *result = NULL;
 278         struct sockaddr_un *local_addr = NULL, *remote_addr = NULL;
 279
 280         src = uml_vector_fetch_arg(ifspec, "src");
 281         dst = uml_vector_fetch_arg(ifspec, "dst");
 282         result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
 283         if (result == NULL) {
 284                 printk(UM_KERN_ERR "unix open:cannot allocate remote addr");
 285                 goto unix_cleanup;
 286         }
 287         remote_addr = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
 288         if (remote_addr == NULL) {
 289                 printk(UM_KERN_ERR "unix open:cannot allocate remote addr");
 290                 goto unix_cleanup;
 291         }
 292
 293         switch (id) {
 294         case ID_BESS:
 295                 socktype = SOCK_SEQPACKET;
 296                 if ((src != NULL) && (strlen(src) <= MAX_UN_LEN)) {
 297                         local_addr = uml_kmalloc(sizeof(struct sockaddr_un), UM_GFP_KERNEL);
 298                         if (local_addr == NULL) {
 299                                 printk(UM_KERN_ERR "bess open:cannot allocate local addr");
 300                                 goto unix_cleanup;
 301                         }
 302                         local_addr->sun_family = AF_UNIX;
 303                         memcpy(local_addr->sun_path, src, strlen(src) + 1);
 304                 }
 305                 if ((dst == NULL) || (strlen(dst) > MAX_UN_LEN))
 306                         goto unix_cleanup;
 307                 remote_addr->sun_family = AF_UNIX;
 308                 memcpy(remote_addr->sun_path, dst, strlen(dst) + 1);
 309                 break;
 310         default:
 311                 printk(KERN_ERR "Unsupported unix socket type\n");
 312                 return NULL;
 313         }
 314
 315         fd = socket(AF_UNIX, socktype, 0);
 316         if (fd == -1) {
 317                 printk(UM_KERN_ERR
 318                         "unix open: could not open socket, error = %d",
 319                         -errno
 320                 );
 321                 goto unix_cleanup;
 322         }
 323         if (local_addr != NULL) {
 324                 if (bind(fd, (struct sockaddr *) local_addr, sizeof(struct sockaddr_un))) {
 325                         printk(UM_KERN_ERR UNIX_BIND_FAIL, errno);
 326                         goto unix_cleanup;
 327                 }
 328         }
 329         switch (id) {
 330         case ID_BESS:
 331                 if (connect(fd, remote_addr, sizeof(struct sockaddr_un)) < 0) {
 332                         printk(UM_KERN_ERR "bess open:cannot connect to %s %i", remote_addr->sun_path, -errno);
 333                         goto unix_cleanup;
 334                 }
 335                 break;
 336         }
 337         result->rx_fd = fd;
 338         result->tx_fd = fd;
 339         result->remote_addr_size = sizeof(struct sockaddr_un);
 340         result->remote_addr = remote_addr;
 341         return result;
 342 unix_cleanup:
 343         if (fd >= 0)
 344                 os_close_file(fd);
 345         kfree(remote_addr);
 346         kfree(result);
 347         return NULL;
 348 }
 349
 350 static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
 351 {
 352         int rxfd = -1, txfd = -1;
 353         int err = -ENOMEM;
 354         char *iface;
 355         struct vector_fds *result = NULL;
 356
 357         iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
 358         if (iface == NULL)
 359                 goto raw_cleanup;
 360
 361         rxfd = create_raw_fd(iface, ETH_P_ALL, ETH_P_ALL);
 362         if (rxfd == -1) {
 363                 err = -errno;
 364                 goto raw_cleanup;
 365         }
 366         txfd = create_raw_fd(iface, 0, ETH_P_IP); /* Turn off RX on this fd */
 367         if (txfd == -1) {
 368                 err = -errno;
 369                 goto raw_cleanup;
 370         }
 371         result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
 372         if (result != NULL) {
 373                 result->rx_fd = rxfd;
 374                 result->tx_fd = txfd;
 375                 result->remote_addr = NULL;
 376                 result->remote_addr_size = 0;
 377         }
 378         return result;
 379 raw_cleanup:
 380         printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);
 381         kfree(result);
 382         return NULL;
 383 }
 384
 385
 386 bool uml_raw_enable_qdisc_bypass(int fd)
 387 {
 388         int optval = 1;
 389
 390         if (setsockopt(fd,
 391                 SOL_PACKET, PACKET_QDISC_BYPASS,
 392                 &optval, sizeof(optval)) != 0) {
 393                 return false;
 394         }
 395         return true;
 396 }
 397
 398 bool uml_raw_enable_vnet_headers(int fd)
 399 {
 400         int optval = 1;
 401
 402         if (setsockopt(fd,
 403                 SOL_PACKET, PACKET_VNET_HDR,
 404                 &optval, sizeof(optval)) != 0) {
 405                 printk(UM_KERN_INFO VNET_HDR_FAIL, fd);
 406                 return false;
 407         }
 408         return true;
 409 }
 410 bool uml_tap_enable_vnet_headers(int fd)
 411 {
 412         unsigned int features;
 413         int len = sizeof(struct virtio_net_hdr);
 414
 415         if (ioctl(fd, TUNGETFEATURES, &features) == -1) {
 416                 printk(UM_KERN_INFO TUN_GET_F_FAIL, strerror(errno));
 417                 return false;
 418         }
 419         if ((features & IFF_VNET_HDR) == 0) {
 420                 printk(UM_KERN_INFO "tapraw: No VNET HEADER support");
 421                 return false;
 422         }
 423         ioctl(fd, TUNSETVNETHDRSZ, &len);
 424         return true;
 425 }
 426
 427 static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
 428 {
 429         int err = -ENOMEM;
 430         int fd = -1, gairet;
 431         struct addrinfo srchints;
 432         struct addrinfo dsthints;
 433         bool v6, udp;
 434         char *value;
 435         char *src, *dst, *srcport, *dstport;
 436         struct addrinfo *gairesult = NULL;
 437         struct vector_fds *result = NULL;
 438
 439
 440         value = uml_vector_fetch_arg(ifspec, "v6");
 441         v6 = false;
 442         udp = false;
 443         if (value != NULL) {
 444                 if (strtol((const char *) value, NULL, 10) > 0)
 445                         v6 = true;
 446         }
 447
 448         value = uml_vector_fetch_arg(ifspec, "udp");
 449         if (value != NULL) {
 450                 if (strtol((const char *) value, NULL, 10) > 0)
 451                         udp = true;
 452         }
 453         src = uml_vector_fetch_arg(ifspec, "src");
 454         dst = uml_vector_fetch_arg(ifspec, "dst");
 455         srcport = uml_vector_fetch_arg(ifspec, "srcport");
 456         dstport = uml_vector_fetch_arg(ifspec, "dstport");
 457
 458         memset(&dsthints, 0, sizeof(dsthints));
 459
 460         if (v6)
 461                 dsthints.ai_family = AF_INET6;
 462         else
 463                 dsthints.ai_family = AF_INET;
 464
 465         switch (id) {
 466         case ID_GRE:
 467                 dsthints.ai_socktype = SOCK_RAW;
 468                 dsthints.ai_protocol = IPPROTO_GRE;
 469                 break;
 470         case ID_L2TPV3:
 471                 if (udp) {
 472                         dsthints.ai_socktype = SOCK_DGRAM;
 473                         dsthints.ai_protocol = 0;
 474                 } else {
 475                         dsthints.ai_socktype = SOCK_RAW;
 476                         dsthints.ai_protocol = IPPROTO_L2TP;
 477                 }
 478                 break;
 479         default:
 480                 printk(KERN_ERR "Unsupported socket type\n");
 481                 return NULL;
 482         }
 483         memcpy(&srchints, &dsthints, sizeof(struct addrinfo));
 484
 485         gairet = getaddrinfo(src, srcport, &dsthints, &gairesult);
 486         if ((gairet != 0) || (gairesult == NULL)) {
 487                 printk(UM_KERN_ERR
 488                         "socket_open : could not resolve src, error = %s",
 489                         gai_strerror(gairet)
 490                 );
 491                 return NULL;
 492         }
 493         fd = socket(gairesult->ai_family,
 494                 gairesult->ai_socktype, gairesult->ai_protocol);
 495         if (fd == -1) {
 496                 printk(UM_KERN_ERR
 497                         "socket_open : could not open socket, error = %d",
 498                         -errno
 499                 );
 500                 goto cleanup;
 501         }
 502         if (bind(fd,
 503                 (struct sockaddr *) gairesult->ai_addr,
 504                 gairesult->ai_addrlen)) {
 505                 printk(UM_KERN_ERR L2TPV3_BIND_FAIL, errno);
 506                 goto cleanup;
 507         }
 508
 509         if (gairesult != NULL)
 510                 freeaddrinfo(gairesult);
 511
 512         gairesult = NULL;
 513
 514         gairet = getaddrinfo(dst, dstport, &dsthints, &gairesult);
 515         if ((gairet != 0) || (gairesult == NULL)) {
 516                 printk(UM_KERN_ERR
 517                         "socket_open : could not resolve dst, error = %s",
 518                         gai_strerror(gairet)
 519                 );
 520                 return NULL;
 521         }
 522
 523         result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
 524         if (result != NULL) {
 525                 result->rx_fd = fd;
 526                 result->tx_fd = fd;
 527                 result->remote_addr = uml_kmalloc(
 528                         gairesult->ai_addrlen, UM_GFP_KERNEL);
 529                 if (result->remote_addr == NULL)
 530                         goto cleanup;
 531                 result->remote_addr_size = gairesult->ai_addrlen;
 532                 memcpy(
 533                         result->remote_addr,
 534                         gairesult->ai_addr,
 535                         gairesult->ai_addrlen
 536                 );
 537         }
 538         freeaddrinfo(gairesult);
 539         return result;
 540 cleanup:
 541         if (gairesult != NULL)
 542                 freeaddrinfo(gairesult);
 543         printk(UM_KERN_ERR "user_init_socket: init failed, error %d", err);
 544         if (fd >= 0)
 545                 os_close_file(fd);
 546         if (result != NULL) {
 547                 kfree(result->remote_addr);
 548                 kfree(result);
 549         }
 550         return NULL;
 551 }
 552
 553 struct vector_fds *uml_vector_user_open(
 554         int unit,
 555         struct arglist *parsed
 556 )
 557 {
 558         char *transport;
 559
 560         if (parsed == NULL) {
 561                 printk(UM_KERN_ERR "no parsed config for unit %d\n", unit);
 562                 return NULL;
 563         }
 564         transport = uml_vector_fetch_arg(parsed, "transport");
 565         if (transport == NULL) {
 566                 printk(UM_KERN_ERR "missing transport for unit %d\n", unit);
 567                 return NULL;
 568         }
 569         if (strncmp(transport, TRANS_RAW, TRANS_RAW_LEN) == 0)
 570                 return user_init_raw_fds(parsed);
 571         if (strncmp(transport, TRANS_HYBRID, TRANS_HYBRID_LEN) == 0)
 572                 return user_init_hybrid_fds(parsed);
 573         if (strncmp(transport, TRANS_TAP, TRANS_TAP_LEN) == 0)
 574                 return user_init_tap_fds(parsed);
 575         if (strncmp(transport, TRANS_GRE, TRANS_GRE_LEN) == 0)
 576                 return user_init_socket_fds(parsed, ID_GRE);
 577         if (strncmp(transport, TRANS_L2TPV3, TRANS_L2TPV3_LEN) == 0)
 578                 return user_init_socket_fds(parsed, ID_L2TPV3);
 579         if (strncmp(transport, TRANS_BESS, TRANS_BESS_LEN) == 0)
 580                 return user_init_unix_fds(parsed, ID_BESS);
 581         return NULL;
 582 }
 583
 584
 585 int uml_vector_sendmsg(int fd, void *hdr, int flags)
 586 {
 587         int n;
 588
 589         CATCH_EINTR(n = sendmsg(fd, (struct msghdr *) hdr,  flags));
 590         if ((n < 0) && (errno == EAGAIN))
 591                 return 0;
 592         if (n >= 0)
 593                 return n;
 594         else
 595                 return -errno;
 596 }
 597
 598 int uml_vector_recvmsg(int fd, void *hdr, int flags)
 599 {
 600         int n;
 601         struct msghdr *msg = (struct msghdr *) hdr;
 602
 603         CATCH_EINTR(n = readv(fd, msg->msg_iov, msg->msg_iovlen));
 604         if ((n < 0) && (errno == EAGAIN))
 605                 return 0;
 606         if (n >= 0)
 607                 return n;
 608         else
 609                 return -errno;
 610 }
 611
 612 int uml_vector_writev(int fd, void *hdr, int iovcount)
 613 {
 614         int n;
 615
 616         CATCH_EINTR(n = writev(fd, (struct iovec *) hdr,  iovcount));
 617         if ((n < 0) && ((errno == EAGAIN) || (errno == ENOBUFS)))
 618                 return 0;
 619         if (n >= 0)
 620                 return n;
 621         else
 622                 return -errno;
 623 }
 624
 625 int uml_vector_sendmmsg(
 626         int fd,
 627         void *msgvec,
 628         unsigned int vlen,
 629         unsigned int flags)
 630 {
 631         int n;
 632
 633         CATCH_EINTR(n = sendmmsg(fd, (struct mmsghdr *) msgvec, vlen, flags));
 634         if ((n < 0) && ((errno == EAGAIN) || (errno == ENOBUFS)))
 635                 return 0;
 636         if (n >= 0)
 637                 return n;
 638         else
 639                 return -errno;
 640 }
 641
 642 int uml_vector_recvmmsg(
 643         int fd,
 644         void *msgvec,
 645         unsigned int vlen,
 646         unsigned int flags)
 647 {
 648         int n;
 649
 650         CATCH_EINTR(
 651                 n = recvmmsg(fd, (struct mmsghdr *) msgvec, vlen, flags, 0));
 652         if ((n < 0) && (errno == EAGAIN))
 653                 return 0;
 654         if (n >= 0)
 655                 return n;
 656         else
 657                 return -errno;
 658 }
 659 int uml_vector_attach_bpf(int fd, void *bpf)
 660 {
 661         struct sock_fprog *prog = bpf;
 662
 663         int err = setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, bpf, sizeof(struct sock_fprog));
 664
 665         if (err < 0)
 666                 printk(KERN_ERR BPF_ATTACH_FAIL, prog->len, prog->filter, fd, -errno);
 667         return err;
 668 }
 669
 670 int uml_vector_detach_bpf(int fd, void *bpf)
 671 {
 672         struct sock_fprog *prog = bpf;
 673
 674         int err = setsockopt(fd, SOL_SOCKET, SO_DETACH_FILTER, bpf, sizeof(struct sock_fprog));
 675         if (err < 0)
 676                 printk(KERN_ERR BPF_DETACH_FAIL, prog->len, prog->filter, fd, -errno);
 677         return err;
 678 }
 679 void *uml_vector_default_bpf(void *mac)
 680 {
 681         struct sock_filter *bpf;
 682         uint32_t *mac1 = (uint32_t *)(mac + 2);
 683         uint16_t *mac2 = (uint16_t *) mac;
 684         struct sock_fprog *bpf_prog;
 685
 686         bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
 687         if (bpf_prog) {
 688                 bpf_prog->len = DEFAULT_BPF_LEN;
 689                 bpf_prog->filter = NULL;
 690         } else {
 691                 return NULL;
 692         }
 693         bpf = uml_kmalloc(
 694                 sizeof(struct sock_filter) * DEFAULT_BPF_LEN, UM_GFP_KERNEL);
 695         if (bpf) {
 696                 bpf_prog->filter = bpf;
 697                 /* ld   [8] */
 698                 bpf[0] = (struct sock_filter){ 0x20, 0, 0, 0x00000008 };
 699                 /* jeq  #0xMAC[2-6] jt 2 jf 5*/
 700                 bpf[1] = (struct sock_filter){ 0x15, 0, 3, ntohl(*mac1)};
 701                 /* ldh  [6] */
 702                 bpf[2] = (struct sock_filter){ 0x28, 0, 0, 0x00000006 };
 703                 /* jeq  #0xMAC[0-1] jt 4 jf 5 */
 704                 bpf[3] = (struct sock_filter){ 0x15, 0, 1, ntohs(*mac2)};
 705                 /* ret  #0 */
 706                 bpf[4] = (struct sock_filter){ 0x6, 0, 0, 0x00000000 };
 707                 /* ret  #0x40000 */
 708                 bpf[5] = (struct sock_filter){ 0x6, 0, 0, 0x00040000 };
 709         } else {
 710                 kfree(bpf_prog);
 711                 bpf_prog = NULL;
 712         }
 713         return bpf_prog;
 714 }
 715
 716 /* Note - this function requires a valid mac being passed as an arg */
 717
 718 void *uml_vector_user_bpf(char *filename)
 719 {
 720         struct sock_filter *bpf;
 721         struct sock_fprog *bpf_prog;
 722         struct stat statbuf;
 723         int res, ffd = -1;
 724
 725         if (filename == NULL)
 726                 return NULL;
 727
 728         if (stat(filename, &statbuf) < 0) {
 729                 printk(KERN_ERR "Error %d reading bpf file", -errno);
 730                 return false;
 731         }
 732         bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL);
 733         if (bpf_prog != NULL) {
 734                 bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter);
 735                 bpf_prog->filter = NULL;
 736         }
 737         ffd = os_open_file(filename, of_read(OPENFLAGS()), 0);
 738         if (ffd < 0) {
 739                 printk(KERN_ERR "Error %d opening bpf file", -errno);
 740                 goto bpf_failed;
 741         }
 742         bpf = uml_kmalloc(statbuf.st_size, UM_GFP_KERNEL);
 743         if (bpf == NULL) {
 744                 printk(KERN_ERR "Failed to allocate bpf buffer");
 745                 goto bpf_failed;
 746         }
 747         bpf_prog->filter = bpf;
 748         res = os_read_file(ffd, bpf, statbuf.st_size);
 749         if (res < statbuf.st_size) {
 750                 printk(KERN_ERR "Failed to read bpf program %s, error %d", filename, res);
 751                 kfree(bpf);
 752                 goto bpf_failed;
 753         }
 754         os_close_file(ffd);
 755         return bpf_prog;
 756 bpf_failed:
 757         if (ffd > 0)
 758                 os_close_file(ffd);
 759         kfree(bpf_prog);
 760         return NULL;
 761 }