tools/bpf/bpftool/common.c

   1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2 /* Copyright (C) 2017-2018 Netronome Systems, Inc. */
   3
   4 #include <ctype.h>
   5 #include <errno.h>
   6 #include <fcntl.h>
   7 #include <fts.h>
   8 #include <libgen.h>
   9 #include <mntent.h>
  10 #include <stdbool.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <unistd.h>
  15 #include <linux/limits.h>
  16 #include <linux/magic.h>
  17 #include <net/if.h>
  18 #include <sys/mount.h>
  19 #include <sys/resource.h>
  20 #include <sys/stat.h>
  21 #include <sys/vfs.h>
  22
  23 #include <bpf/bpf.h>
  24 #include <bpf/libbpf.h> /* libbpf_num_possible_cpus */
  25
  26 #include "main.h"
  27
  28 #ifndef BPF_FS_MAGIC
  29 #define BPF_FS_MAGIC            0xcafe4a11
  30 #endif
  31
  32 void p_err(const char *fmt, ...)
  33 {
  34         va_list ap;
  35
  36         va_start(ap, fmt);
  37         if (json_output) {
  38                 jsonw_start_object(json_wtr);
  39                 jsonw_name(json_wtr, "error");
  40                 jsonw_vprintf_enquote(json_wtr, fmt, ap);
  41                 jsonw_end_object(json_wtr);
  42         } else {
  43                 fprintf(stderr, "Error: ");
  44                 vfprintf(stderr, fmt, ap);
  45                 fprintf(stderr, "\n");
  46         }
  47         va_end(ap);
  48 }
  49
  50 void p_info(const char *fmt, ...)
  51 {
  52         va_list ap;
  53
  54         if (json_output)
  55                 return;
  56
  57         va_start(ap, fmt);
  58         vfprintf(stderr, fmt, ap);
  59         fprintf(stderr, "\n");
  60         va_end(ap);
  61 }
  62
  63 static bool is_bpffs(char *path)
  64 {
  65         struct statfs st_fs;
  66
  67         if (statfs(path, &st_fs) < 0)
  68                 return false;
  69
  70         return (unsigned long)st_fs.f_type == BPF_FS_MAGIC;
  71 }
  72
  73 void set_max_rlimit(void)
  74 {
  75         struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
  76
  77         setrlimit(RLIMIT_MEMLOCK, &rinf);
  78 }
  79
  80 static int
  81 mnt_fs(const char *target, const char *type, char *buff, size_t bufflen)
  82 {
  83         bool bind_done = false;
  84
  85         while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) {
  86                 if (errno != EINVAL || bind_done) {
  87                         snprintf(buff, bufflen,
  88                                  "mount --make-private %s failed: %s",
  89                                  target, strerror(errno));
  90                         return -1;
  91                 }
  92
  93                 if (mount(target, target, "none", MS_BIND, NULL)) {
  94                         snprintf(buff, bufflen,
  95                                  "mount --bind %s %s failed: %s",
  96                                  target, target, strerror(errno));
  97                         return -1;
  98                 }
  99
 100                 bind_done = true;
 101         }
 102
 103         if (mount(type, target, type, 0, "mode=0700")) {
 104                 snprintf(buff, bufflen, "mount -t %s %s %s failed: %s",
 105                          type, type, target, strerror(errno));
 106                 return -1;
 107         }
 108
 109         return 0;
 110 }
 111
 112 int mount_tracefs(const char *target)
 113 {
 114         char err_str[ERR_MAX_LEN];
 115         int err;
 116
 117         err = mnt_fs(target, "tracefs", err_str, ERR_MAX_LEN);
 118         if (err) {
 119                 err_str[ERR_MAX_LEN - 1] = '\0';
 120                 p_err("can't mount tracefs: %s", err_str);
 121         }
 122
 123         return err;
 124 }
 125
 126 int open_obj_pinned(char *path, bool quiet)
 127 {
 128         int fd;
 129
 130         fd = bpf_obj_get(path);
 131         if (fd < 0) {
 132                 if (!quiet)
 133                         p_err("bpf obj get (%s): %s", path,
 134                               errno == EACCES && !is_bpffs(dirname(path)) ?
 135                             "directory not in bpf file system (bpffs)" :
 136                             strerror(errno));
 137                 return -1;
 138         }
 139
 140         return fd;
 141 }
 142
 143 int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type)
 144 {
 145         enum bpf_obj_type type;
 146         int fd;
 147
 148         fd = open_obj_pinned(path, false);
 149         if (fd < 0)
 150                 return -1;
 151
 152         type = get_fd_type(fd);
 153         if (type < 0) {
 154                 close(fd);
 155                 return type;
 156         }
 157         if (type != exp_type) {
 158                 p_err("incorrect object type: %s", get_fd_type_name(type));
 159                 close(fd);
 160                 return -1;
 161         }
 162
 163         return fd;
 164 }
 165
 166 int mount_bpffs_for_pin(const char *name)
 167 {
 168         char err_str[ERR_MAX_LEN];
 169         char *file;
 170         char *dir;
 171         int err = 0;
 172
 173         file = malloc(strlen(name) + 1);
 174         strcpy(file, name);
 175         dir = dirname(file);
 176
 177         if (is_bpffs(dir))
 178                 /* nothing to do if already mounted */
 179                 goto out_free;
 180
 181         if (block_mount) {
 182                 p_err("no BPF file system found, not mounting it due to --nomount option");
 183                 err = -1;
 184                 goto out_free;
 185         }
 186
 187         err = mnt_fs(dir, "bpf", err_str, ERR_MAX_LEN);
 188         if (err) {
 189                 err_str[ERR_MAX_LEN - 1] = '\0';
 190                 p_err("can't mount BPF file system to pin the object (%s): %s",
 191                       name, err_str);
 192         }
 193
 194 out_free:
 195         free(file);
 196         return err;
 197 }
 198
 199 int do_pin_fd(int fd, const char *name)
 200 {
 201         int err;
 202
 203         err = mount_bpffs_for_pin(name);
 204         if (err)
 205                 return err;
 206
 207         err = bpf_obj_pin(fd, name);
 208         if (err)
 209                 p_err("can't pin the object (%s): %s", name, strerror(errno));
 210
 211         return err;
 212 }
 213
 214 int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
 215 {
 216         unsigned int id;
 217         char *endptr;
 218         int err;
 219         int fd;
 220
 221         if (argc < 3) {
 222                 p_err("too few arguments, id ID and FILE path is required");
 223                 return -1;
 224         } else if (argc > 3) {
 225                 p_err("too many arguments");
 226                 return -1;
 227         }
 228
 229         if (!is_prefix(*argv, "id")) {
 230                 p_err("expected 'id' got %s", *argv);
 231                 return -1;
 232         }
 233         NEXT_ARG();
 234
 235         id = strtoul(*argv, &endptr, 0);
 236         if (*endptr) {
 237                 p_err("can't parse %s as ID", *argv);
 238                 return -1;
 239         }
 240         NEXT_ARG();
 241
 242         fd = get_fd_by_id(id);
 243         if (fd < 0) {
 244                 p_err("can't open object by id (%u): %s", id, strerror(errno));
 245                 return -1;
 246         }
 247
 248         err = do_pin_fd(fd, *argv);
 249
 250         close(fd);
 251         return err;
 252 }
 253
 254 const char *get_fd_type_name(enum bpf_obj_type type)
 255 {
 256         static const char * const names[] = {
 257                 [BPF_OBJ_UNKNOWN]       = "unknown",
 258                 [BPF_OBJ_PROG]          = "prog",
 259                 [BPF_OBJ_MAP]           = "map",
 260         };
 261
 262         if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
 263                 return names[BPF_OBJ_UNKNOWN];
 264
 265         return names[type];
 266 }
 267
 268 int get_fd_type(int fd)
 269 {
 270         char path[PATH_MAX];
 271         char buf[512];
 272         ssize_t n;
 273
 274         snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);
 275
 276         n = readlink(path, buf, sizeof(buf));
 277         if (n < 0) {
 278                 p_err("can't read link type: %s", strerror(errno));
 279                 return -1;
 280         }
 281         if (n == sizeof(path)) {
 282                 p_err("can't read link type: path too long!");
 283                 return -1;
 284         }
 285
 286         if (strstr(buf, "bpf-map"))
 287                 return BPF_OBJ_MAP;
 288         else if (strstr(buf, "bpf-prog"))
 289                 return BPF_OBJ_PROG;
 290
 291         return BPF_OBJ_UNKNOWN;
 292 }
 293
 294 char *get_fdinfo(int fd, const char *key)
 295 {
 296         char path[PATH_MAX];
 297         char *line = NULL;
 298         size_t line_n = 0;
 299         ssize_t n;
 300         FILE *fdi;
 301
 302         snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd);
 303
 304         fdi = fopen(path, "r");
 305         if (!fdi)
 306                 return NULL;
 307
 308         while ((n = getline(&line, &line_n, fdi)) > 0) {
 309                 char *value;
 310                 int len;
 311
 312                 if (!strstr(line, key))
 313                         continue;
 314
 315                 fclose(fdi);
 316
 317                 value = strchr(line, '\t');
 318                 if (!value || !value[1]) {
 319                         free(line);
 320                         return NULL;
 321                 }
 322                 value++;
 323
 324                 len = strlen(value);
 325                 memmove(line, value, len);
 326                 line[len - 1] = '\0';
 327
 328                 return line;
 329         }
 330
 331         free(line);
 332         fclose(fdi);
 333         return NULL;
 334 }
 335
 336 void print_data_json(uint8_t *data, size_t len)
 337 {
 338         unsigned int i;
 339
 340         jsonw_start_array(json_wtr);
 341         for (i = 0; i < len; i++)
 342                 jsonw_printf(json_wtr, "%d", data[i]);
 343         jsonw_end_array(json_wtr);
 344 }
 345
 346 void print_hex_data_json(uint8_t *data, size_t len)
 347 {
 348         unsigned int i;
 349
 350         jsonw_start_array(json_wtr);
 351         for (i = 0; i < len; i++)
 352                 jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
 353         jsonw_end_array(json_wtr);
 354 }
 355
 356 int build_pinned_obj_table(struct pinned_obj_table *tab,
 357                            enum bpf_obj_type type)
 358 {
 359         struct bpf_prog_info pinned_info = {};
 360         struct pinned_obj *obj_node = NULL;
 361         __u32 len = sizeof(pinned_info);
 362         struct mntent *mntent = NULL;
 363         enum bpf_obj_type objtype;
 364         FILE *mntfile = NULL;
 365         FTSENT *ftse = NULL;
 366         FTS *fts = NULL;
 367         int fd, err;
 368
 369         mntfile = setmntent("/proc/mounts", "r");
 370         if (!mntfile)
 371                 return -1;
 372
 373         while ((mntent = getmntent(mntfile))) {
 374                 char *path[] = { mntent->mnt_dir, NULL };
 375
 376                 if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
 377                         continue;
 378
 379                 fts = fts_open(path, 0, NULL);
 380                 if (!fts)
 381                         continue;
 382
 383                 while ((ftse = fts_read(fts))) {
 384                         if (!(ftse->fts_info & FTS_F))
 385                                 continue;
 386                         fd = open_obj_pinned(ftse->fts_path, true);
 387                         if (fd < 0)
 388                                 continue;
 389
 390                         objtype = get_fd_type(fd);
 391                         if (objtype != type) {
 392                                 close(fd);
 393                                 continue;
 394                         }
 395                         memset(&pinned_info, 0, sizeof(pinned_info));
 396                         err = bpf_obj_get_info_by_fd(fd, &pinned_info, &len);
 397                         if (err) {
 398                                 close(fd);
 399                                 continue;
 400                         }
 401
 402                         obj_node = malloc(sizeof(*obj_node));
 403                         if (!obj_node) {
 404                                 close(fd);
 405                                 fts_close(fts);
 406                                 fclose(mntfile);
 407                                 return -1;
 408                         }
 409
 410                         memset(obj_node, 0, sizeof(*obj_node));
 411                         obj_node->id = pinned_info.id;
 412                         obj_node->path = strdup(ftse->fts_path);
 413                         hash_add(tab->table, &obj_node->hash, obj_node->id);
 414
 415                         close(fd);
 416                 }
 417                 fts_close(fts);
 418         }
 419         fclose(mntfile);
 420         return 0;
 421 }
 422
 423 void delete_pinned_obj_table(struct pinned_obj_table *tab)
 424 {
 425         struct pinned_obj *obj;
 426         struct hlist_node *tmp;
 427         unsigned int bkt;
 428
 429         hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
 430                 hash_del(&obj->hash);
 431                 free(obj->path);
 432                 free(obj);
 433         }
 434 }
 435
 436 unsigned int get_page_size(void)
 437 {
 438         static int result;
 439
 440         if (!result)
 441                 result = getpagesize();
 442         return result;
 443 }
 444
 445 unsigned int get_possible_cpus(void)
 446 {
 447         int cpus = libbpf_num_possible_cpus();
 448
 449         if (cpus < 0) {
 450                 p_err("Can't get # of possible cpus: %s", strerror(-cpus));
 451                 exit(-1);
 452         }
 453         return cpus;
 454 }
 455
 456 static char *
 457 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
 458 {
 459         struct stat st;
 460         int err;
 461
 462         err = stat("/proc/self/ns/net", &st);
 463         if (err) {
 464                 p_err("Can't stat /proc/self: %s", strerror(errno));
 465                 return NULL;
 466         }
 467
 468         if (st.st_dev != ns_dev || st.st_ino != ns_ino)
 469                 return NULL;
 470
 471         return if_indextoname(ifindex, buf);
 472 }
 473
 474 static int read_sysfs_hex_int(char *path)
 475 {
 476         char vendor_id_buf[8];
 477         int len;
 478         int fd;
 479
 480         fd = open(path, O_RDONLY);
 481         if (fd < 0) {
 482                 p_err("Can't open %s: %s", path, strerror(errno));
 483                 return -1;
 484         }
 485
 486         len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
 487         close(fd);
 488         if (len < 0) {
 489                 p_err("Can't read %s: %s", path, strerror(errno));
 490                 return -1;
 491         }
 492         if (len >= (int)sizeof(vendor_id_buf)) {
 493                 p_err("Value in %s too long", path);
 494                 return -1;
 495         }
 496
 497         vendor_id_buf[len] = 0;
 498
 499         return strtol(vendor_id_buf, NULL, 0);
 500 }
 501
 502 static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
 503 {
 504         char full_path[64];
 505
 506         snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
 507                  devname, entry_name);
 508
 509         return read_sysfs_hex_int(full_path);
 510 }
 511
 512 const char *
 513 ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
 514                       const char **opt)
 515 {
 516         char devname[IF_NAMESIZE];
 517         int vendor_id;
 518         int device_id;
 519
 520         if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
 521                 p_err("Can't get net device name for ifindex %d: %s", ifindex,
 522                       strerror(errno));
 523                 return NULL;
 524         }
 525
 526         vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
 527         if (vendor_id < 0) {
 528                 p_err("Can't get device vendor id for %s", devname);
 529                 return NULL;
 530         }
 531
 532         switch (vendor_id) {
 533         case 0x19ee:
 534                 device_id = read_sysfs_netdev_hex_int(devname, "device");
 535                 if (device_id != 0x4000 &&
 536                     device_id != 0x6000 &&
 537                     device_id != 0x6003)
 538                         p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
 539                 *opt = "ctx4";
 540                 return "NFP-6xxx";
 541         default:
 542                 p_err("Can't get bfd arch name for device vendor id 0x%04x",
 543                       vendor_id);
 544                 return NULL;
 545         }
 546 }
 547
 548 void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
 549 {
 550         char name[IF_NAMESIZE];
 551
 552         if (!ifindex)
 553                 return;
 554
 555         printf("  offloaded_to ");
 556         if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
 557                 printf("%s", name);
 558         else
 559                 printf("ifindex %u ns_dev %llu ns_ino %llu",
 560                        ifindex, ns_dev, ns_inode);
 561 }
 562
 563 void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
 564 {
 565         char name[IF_NAMESIZE];
 566
 567         if (!ifindex)
 568                 return;
 569
 570         jsonw_name(json_wtr, "dev");
 571         jsonw_start_object(json_wtr);
 572         jsonw_uint_field(json_wtr, "ifindex", ifindex);
 573         jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
 574         jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
 575         if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
 576                 jsonw_string_field(json_wtr, "ifname", name);
 577         jsonw_end_object(json_wtr);
 578 }
 579
 580 int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what)
 581 {
 582         char *endptr;
 583
 584         NEXT_ARGP();
 585
 586         if (*val) {
 587                 p_err("%s already specified", what);
 588                 return -1;
 589         }
 590
 591         *val = strtoul(**argv, &endptr, 0);
 592         if (*endptr) {
 593                 p_err("can't parse %s as %s", **argv, what);
 594                 return -1;
 595         }
 596         NEXT_ARGP();
 597
 598         return 0;
 599 }