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)(int *, char ***))
 215 {
 216         int err;
 217         int fd;
 218
 219         fd = get_fd(&argc, &argv);
 220         if (fd < 0)
 221                 return fd;
 222
 223         err = do_pin_fd(fd, *argv);
 224
 225         close(fd);
 226         return err;
 227 }
 228
 229 const char *get_fd_type_name(enum bpf_obj_type type)
 230 {
 231         static const char * const names[] = {
 232                 [BPF_OBJ_UNKNOWN]       = "unknown",
 233                 [BPF_OBJ_PROG]          = "prog",
 234                 [BPF_OBJ_MAP]           = "map",
 235         };
 236
 237         if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
 238                 return names[BPF_OBJ_UNKNOWN];
 239
 240         return names[type];
 241 }
 242
 243 int get_fd_type(int fd)
 244 {
 245         char path[PATH_MAX];
 246         char buf[512];
 247         ssize_t n;
 248
 249         snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);
 250
 251         n = readlink(path, buf, sizeof(buf));
 252         if (n < 0) {
 253                 p_err("can't read link type: %s", strerror(errno));
 254                 return -1;
 255         }
 256         if (n == sizeof(path)) {
 257                 p_err("can't read link type: path too long!");
 258                 return -1;
 259         }
 260
 261         if (strstr(buf, "bpf-map"))
 262                 return BPF_OBJ_MAP;
 263         else if (strstr(buf, "bpf-prog"))
 264                 return BPF_OBJ_PROG;
 265
 266         return BPF_OBJ_UNKNOWN;
 267 }
 268
 269 char *get_fdinfo(int fd, const char *key)
 270 {
 271         char path[PATH_MAX];
 272         char *line = NULL;
 273         size_t line_n = 0;
 274         ssize_t n;
 275         FILE *fdi;
 276
 277         snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd);
 278
 279         fdi = fopen(path, "r");
 280         if (!fdi)
 281                 return NULL;
 282
 283         while ((n = getline(&line, &line_n, fdi)) > 0) {
 284                 char *value;
 285                 int len;
 286
 287                 if (!strstr(line, key))
 288                         continue;
 289
 290                 fclose(fdi);
 291
 292                 value = strchr(line, '\t');
 293                 if (!value || !value[1]) {
 294                         free(line);
 295                         return NULL;
 296                 }
 297                 value++;
 298
 299                 len = strlen(value);
 300                 memmove(line, value, len);
 301                 line[len - 1] = '\0';
 302
 303                 return line;
 304         }
 305
 306         free(line);
 307         fclose(fdi);
 308         return NULL;
 309 }
 310
 311 void print_data_json(uint8_t *data, size_t len)
 312 {
 313         unsigned int i;
 314
 315         jsonw_start_array(json_wtr);
 316         for (i = 0; i < len; i++)
 317                 jsonw_printf(json_wtr, "%d", data[i]);
 318         jsonw_end_array(json_wtr);
 319 }
 320
 321 void print_hex_data_json(uint8_t *data, size_t len)
 322 {
 323         unsigned int i;
 324
 325         jsonw_start_array(json_wtr);
 326         for (i = 0; i < len; i++)
 327                 jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
 328         jsonw_end_array(json_wtr);
 329 }
 330
 331 int build_pinned_obj_table(struct pinned_obj_table *tab,
 332                            enum bpf_obj_type type)
 333 {
 334         struct bpf_prog_info pinned_info = {};
 335         struct pinned_obj *obj_node = NULL;
 336         __u32 len = sizeof(pinned_info);
 337         struct mntent *mntent = NULL;
 338         enum bpf_obj_type objtype;
 339         FILE *mntfile = NULL;
 340         FTSENT *ftse = NULL;
 341         FTS *fts = NULL;
 342         int fd, err;
 343
 344         mntfile = setmntent("/proc/mounts", "r");
 345         if (!mntfile)
 346                 return -1;
 347
 348         while ((mntent = getmntent(mntfile))) {
 349                 char *path[] = { mntent->mnt_dir, NULL };
 350
 351                 if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
 352                         continue;
 353
 354                 fts = fts_open(path, 0, NULL);
 355                 if (!fts)
 356                         continue;
 357
 358                 while ((ftse = fts_read(fts))) {
 359                         if (!(ftse->fts_info & FTS_F))
 360                                 continue;
 361                         fd = open_obj_pinned(ftse->fts_path, true);
 362                         if (fd < 0)
 363                                 continue;
 364
 365                         objtype = get_fd_type(fd);
 366                         if (objtype != type) {
 367                                 close(fd);
 368                                 continue;
 369                         }
 370                         memset(&pinned_info, 0, sizeof(pinned_info));
 371                         err = bpf_obj_get_info_by_fd(fd, &pinned_info, &len);
 372                         if (err) {
 373                                 close(fd);
 374                                 continue;
 375                         }
 376
 377                         obj_node = malloc(sizeof(*obj_node));
 378                         if (!obj_node) {
 379                                 close(fd);
 380                                 fts_close(fts);
 381                                 fclose(mntfile);
 382                                 return -1;
 383                         }
 384
 385                         memset(obj_node, 0, sizeof(*obj_node));
 386                         obj_node->id = pinned_info.id;
 387                         obj_node->path = strdup(ftse->fts_path);
 388                         hash_add(tab->table, &obj_node->hash, obj_node->id);
 389
 390                         close(fd);
 391                 }
 392                 fts_close(fts);
 393         }
 394         fclose(mntfile);
 395         return 0;
 396 }
 397
 398 void delete_pinned_obj_table(struct pinned_obj_table *tab)
 399 {
 400         struct pinned_obj *obj;
 401         struct hlist_node *tmp;
 402         unsigned int bkt;
 403
 404         hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
 405                 hash_del(&obj->hash);
 406                 free(obj->path);
 407                 free(obj);
 408         }
 409 }
 410
 411 unsigned int get_page_size(void)
 412 {
 413         static int result;
 414
 415         if (!result)
 416                 result = getpagesize();
 417         return result;
 418 }
 419
 420 unsigned int get_possible_cpus(void)
 421 {
 422         int cpus = libbpf_num_possible_cpus();
 423
 424         if (cpus < 0) {
 425                 p_err("Can't get # of possible cpus: %s", strerror(-cpus));
 426                 exit(-1);
 427         }
 428         return cpus;
 429 }
 430
 431 static char *
 432 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
 433 {
 434         struct stat st;
 435         int err;
 436
 437         err = stat("/proc/self/ns/net", &st);
 438         if (err) {
 439                 p_err("Can't stat /proc/self: %s", strerror(errno));
 440                 return NULL;
 441         }
 442
 443         if (st.st_dev != ns_dev || st.st_ino != ns_ino)
 444                 return NULL;
 445
 446         return if_indextoname(ifindex, buf);
 447 }
 448
 449 static int read_sysfs_hex_int(char *path)
 450 {
 451         char vendor_id_buf[8];
 452         int len;
 453         int fd;
 454
 455         fd = open(path, O_RDONLY);
 456         if (fd < 0) {
 457                 p_err("Can't open %s: %s", path, strerror(errno));
 458                 return -1;
 459         }
 460
 461         len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
 462         close(fd);
 463         if (len < 0) {
 464                 p_err("Can't read %s: %s", path, strerror(errno));
 465                 return -1;
 466         }
 467         if (len >= (int)sizeof(vendor_id_buf)) {
 468                 p_err("Value in %s too long", path);
 469                 return -1;
 470         }
 471
 472         vendor_id_buf[len] = 0;
 473
 474         return strtol(vendor_id_buf, NULL, 0);
 475 }
 476
 477 static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
 478 {
 479         char full_path[64];
 480
 481         snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
 482                  devname, entry_name);
 483
 484         return read_sysfs_hex_int(full_path);
 485 }
 486
 487 const char *
 488 ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
 489                       const char **opt)
 490 {
 491         char devname[IF_NAMESIZE];
 492         int vendor_id;
 493         int device_id;
 494
 495         if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
 496                 p_err("Can't get net device name for ifindex %d: %s", ifindex,
 497                       strerror(errno));
 498                 return NULL;
 499         }
 500
 501         vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
 502         if (vendor_id < 0) {
 503                 p_err("Can't get device vendor id for %s", devname);
 504                 return NULL;
 505         }
 506
 507         switch (vendor_id) {
 508         case 0x19ee:
 509                 device_id = read_sysfs_netdev_hex_int(devname, "device");
 510                 if (device_id != 0x4000 &&
 511                     device_id != 0x6000 &&
 512                     device_id != 0x6003)
 513                         p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
 514                 *opt = "ctx4";
 515                 return "NFP-6xxx";
 516         default:
 517                 p_err("Can't get bfd arch name for device vendor id 0x%04x",
 518                       vendor_id);
 519                 return NULL;
 520         }
 521 }
 522
 523 void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
 524 {
 525         char name[IF_NAMESIZE];
 526
 527         if (!ifindex)
 528                 return;
 529
 530         printf("  offloaded_to ");
 531         if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
 532                 printf("%s", name);
 533         else
 534                 printf("ifindex %u ns_dev %llu ns_ino %llu",
 535                        ifindex, ns_dev, ns_inode);
 536 }
 537
 538 void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
 539 {
 540         char name[IF_NAMESIZE];
 541
 542         if (!ifindex)
 543                 return;
 544
 545         jsonw_name(json_wtr, "dev");
 546         jsonw_start_object(json_wtr);
 547         jsonw_uint_field(json_wtr, "ifindex", ifindex);
 548         jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
 549         jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
 550         if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
 551                 jsonw_string_field(json_wtr, "ifname", name);
 552         jsonw_end_object(json_wtr);
 553 }
 554
 555 int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what)
 556 {
 557         char *endptr;
 558
 559         NEXT_ARGP();
 560
 561         if (*val) {
 562                 p_err("%s already specified", what);
 563                 return -1;
 564         }
 565
 566         *val = strtoul(**argv, &endptr, 0);
 567         if (*endptr) {
 568                 p_err("can't parse %s as %s", **argv, what);
 569                 return -1;
 570         }
 571         NEXT_ARGP();
 572
 573         return 0;
 574 }
 575
 576 int __printf(2, 0)
 577 print_all_levels(__maybe_unused enum libbpf_print_level level,
 578                  const char *format, va_list args)
 579 {
 580         return vfprintf(stderr, format, args);
 581 }