utils/utils.c

   1 /*
   2  * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #define _GNU_SOURCE
  16 #include <libubox/avl.h>
  17 #include <libubox/avl-cmp.h>
  18 #include "utils.h"
  19 #include <regex.h>
  20 #include <unistd.h>
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <fcntl.h>
  24 #include <string.h>
  25 #include <errno.h>
  26
  27 #include "../log.h"
  28
  29 #ifndef O_PATH
  30 #define O_PATH          010000000
  31 #endif
  32
  33 void
  34 __blobmsg_list_init(struct blobmsg_list *list, int offset, int len, blobmsg_list_cmp cmp)
  35 {
  36         avl_init(&list->avl, avl_strcmp, false, NULL);
  37         list->node_offset = offset;
  38         list->node_len = len;
  39         list->cmp = cmp;
  40 }
  41
  42 int
  43 blobmsg_list_fill(struct blobmsg_list *list, void *data, int len, bool array)
  44 {
  45         struct avl_tree *tree = &list->avl;
  46         struct blobmsg_list_node *node;
  47         struct blob_attr *cur;
  48         void *ptr;
  49         int count = 0;
  50         int rem = len;
  51
  52         __blob_for_each_attr(cur, data, rem) {
  53                 if (!blobmsg_check_attr(cur, !array))
  54                         continue;
  55
  56                 ptr = calloc(1, list->node_len);
  57                 if (!ptr)
  58                         return -1;
  59
  60                 node = (void *) ((char *)ptr + list->node_offset);
  61                 if (array)
  62                         node->avl.key = blobmsg_data(cur);
  63                 else
  64                         node->avl.key = blobmsg_name(cur);
  65                 node->data = cur;
  66                 if (avl_insert(tree, &node->avl)) {
  67                         free(ptr);
  68                         continue;
  69                 }
  70
  71                 count++;
  72         }
  73
  74         return count;
  75 }
  76
  77 void
  78 blobmsg_list_move(struct blobmsg_list *list, struct blobmsg_list *src)
  79 {
  80         struct blobmsg_list_node *node, *tmp;
  81         void *ptr;
  82
  83         avl_remove_all_elements(&src->avl, node, avl, tmp) {
  84                 if (avl_insert(&list->avl, &node->avl)) {
  85                         ptr = ((char *) node - list->node_offset);
  86                         free(ptr);
  87                 }
  88         }
  89 }
  90
  91 void
  92 blobmsg_list_free(struct blobmsg_list *list)
  93 {
  94         struct blobmsg_list_node *node, *tmp;
  95         void *ptr;
  96
  97         avl_remove_all_elements(&list->avl, node, avl, tmp) {
  98                 ptr = ((char *) node - list->node_offset);
  99                 free(ptr);
 100         }
 101 }
 102
 103 bool
 104 blobmsg_list_equal(struct blobmsg_list *l1, struct blobmsg_list *l2)
 105 {
 106         struct blobmsg_list_node *n1, *n2;
 107         int count = l1->avl.count;
 108
 109         if (count != l2->avl.count)
 110                 return false;
 111
 112         n1 = avl_first_element(&l1->avl, n1, avl);
 113         n2 = avl_first_element(&l2->avl, n2, avl);
 114
 115         while (count-- > 0) {
 116                 int len;
 117
 118                 len = blob_len(n1->data);
 119                 if (len != blob_len(n2->data))
 120                         return false;
 121
 122                 if (memcmp(n1->data, n2->data, len) != 0)
 123                         return false;
 124
 125                 if (l1->cmp && !l1->cmp(n1, n2))
 126                         return false;
 127
 128                 if (!count)
 129                         break;
 130
 131                 n1 = avl_next_element(n1, avl);
 132                 n2 = avl_next_element(n2, avl);
 133         }
 134
 135         return true;
 136 }
 137
 138 char *get_active_console(char *out, int len)
 139 {
 140         char line[CMDLINE_SIZE + 1];
 141         int fd = open("/sys/class/tty/console/active", O_RDONLY);
 142         ssize_t r = read(fd, line, sizeof(line) - 1);
 143         line[CMDLINE_SIZE] = '\0';
 144
 145         close(fd);
 146
 147         if (r <= 0)
 148                 return NULL;
 149
 150         /* The active file is terminated by a newline which we need to strip */
 151         char *newline = strtok(line, "\n");
 152
 153         if (newline != NULL) {
 154                 strncpy(out, newline, len);
 155                 return out;
 156         }
 157
 158         return NULL;
 159 }
 160
 161 char* get_cmdline_val(const char* name, char* out, int len)
 162 {
 163         char line[CMDLINE_SIZE + 1], *c, *sptr;
 164         int fd = open("/proc/cmdline", O_RDONLY);
 165         ssize_t r = read(fd, line, sizeof(line) - 1);
 166         close(fd);
 167
 168         if (r <= 0)
 169                 return NULL;
 170
 171         line[r] = 0;
 172
 173         for (c = strtok_r(line, " \t\n", &sptr); c;
 174                         c = strtok_r(NULL, " \t\n", &sptr)) {
 175                 char *sep = strchr(c, '=');
 176                 if (sep == NULL)
 177                         continue;
 178
 179                 ssize_t klen = sep - c;
 180                 if (strncmp(name, c, klen) || name[klen] != 0)
 181                         continue;
 182
 183                 strncpy(out, &sep[1], len);
 184                 out[len-1] = 0;
 185                 return out;
 186         }
 187
 188         return NULL;
 189 }
 190
 191 int patch_fd(const char *device, int fd, int flags)
 192 {
 193         int dfd, nfd;
 194
 195         if (device == NULL)
 196                 device = "/dev/null";
 197
 198         if (*device != '/') {
 199                 dfd = open("/dev", O_PATH|O_DIRECTORY);
 200
 201                 if (dfd < 0)
 202                         return -1;
 203
 204                 nfd = openat(dfd, device, flags);
 205
 206                 close(dfd);
 207         } else {
 208                 nfd = open(device, flags);
 209         }
 210
 211         if (nfd < 0 && strcmp(device, "/dev/null"))
 212                 nfd = open("/dev/null", flags);
 213
 214         if (nfd < 0)
 215                 return -1;
 216
 217         fd = dup2(nfd, fd);
 218
 219         if (nfd > STDERR_FILENO)
 220                 close(nfd);
 221
 222         return (fd < 0) ? -1 : 0;
 223 }
 224
 225 int patch_stdio(const char *device)
 226 {
 227         int fd, rv = 0;
 228         const char *fdname[3] = { "stdin", "stdout", "stderr" };
 229
 230         for (fd = STDIN_FILENO; fd <= STDERR_FILENO; fd++) {
 231                 if (patch_fd(device, fd, fd ? O_WRONLY : O_RDONLY)) {
 232                         ERROR("Failed to redirect %s to %s: %m\n",
 233                               fdname[fd], device);
 234                         rv = -1;
 235                 }
 236         }
 237
 238         return rv;
 239 }