utils.c

   1 /*
   2  * netifd - network interface daemon
   3  * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2
   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 #include <string.h>
  15 #include <stdlib.h>
  16 #include "utils.h"
  17
  18 #include <arpa/inet.h>
  19 #include <netinet/in.h>
  20
  21 #ifdef __APPLE__
  22 #include <libproc.h>
  23 #endif
  24
  25 void
  26 __vlist_simple_init(struct vlist_simple_tree *tree, int offset)
  27 {
  28         INIT_LIST_HEAD(&tree->list);
  29         tree->version = 1;
  30         tree->head_offset = offset;
  31 }
  32
  33 void
  34 vlist_simple_delete(struct vlist_simple_tree *tree, struct vlist_simple_node *node)
  35 {
  36         char *ptr;
  37
  38         list_del(&node->list);
  39         ptr = (char *) node - tree->head_offset;
  40         free(ptr);
  41 }
  42
  43 void
  44 vlist_simple_flush(struct vlist_simple_tree *tree)
  45 {
  46         struct vlist_simple_node *n, *tmp;
  47
  48         list_for_each_entry_safe(n, tmp, &tree->list, list) {
  49                 if ((n->version == tree->version || n->version == -1) &&
  50                     tree->version != -1)
  51                         continue;
  52
  53                 vlist_simple_delete(tree, n);
  54         }
  55 }
  56
  57 void
  58 vlist_simple_replace(struct vlist_simple_tree *dest, struct vlist_simple_tree *old)
  59 {
  60         struct vlist_simple_node *n, *tmp;
  61
  62         vlist_simple_update(dest);
  63         list_for_each_entry_safe(n, tmp, &old->list, list) {
  64                 list_del(&n->list);
  65                 vlist_simple_add(dest, n);
  66         }
  67         vlist_simple_flush(dest);
  68 }
  69
  70 void
  71 vlist_simple_flush_all(struct vlist_simple_tree *tree)
  72 {
  73         tree->version = -1;
  74         vlist_simple_flush(tree);
  75 }
  76
  77 unsigned int
  78 parse_netmask_string(const char *str, bool v6)
  79 {
  80         struct in_addr addr;
  81         unsigned int ret;
  82         char *err = NULL;
  83
  84         if (!strchr(str, '.')) {
  85                 ret = strtoul(str, &err, 0);
  86                 if (err && *err)
  87                         goto error;
  88
  89                 return ret;
  90         }
  91
  92         if (v6)
  93                 goto error;
  94
  95         if (inet_aton(str, &addr) != 1)
  96                 goto error;
  97
  98         return 32 - fls(~(ntohl(addr.s_addr)));
  99
 100 error:
 101         return ~0;
 102 }
 103
 104 bool
 105 split_netmask(char *str, unsigned int *netmask, bool v6)
 106 {
 107         char *delim = strchr(str, '/');
 108
 109         if (delim) {
 110                 *(delim++) = 0;
 111
 112                 *netmask = parse_netmask_string(delim, v6);
 113         }
 114         return true;
 115 }
 116
 117 int
 118 parse_ip_and_netmask(int af, const char *str, void *addr, unsigned int *netmask)
 119 {
 120         char *astr = alloca(strlen(str) + 1);
 121
 122         strcpy(astr, str);
 123         if (!split_netmask(astr, netmask, af == AF_INET6))
 124                 return 0;
 125
 126         if (af == AF_INET6) {
 127                 if (*netmask > 128)
 128                         return 0;
 129         } else {
 130                 if (*netmask > 32)
 131                         return 0;
 132         }
 133
 134         return inet_pton(af, astr, addr);
 135 }
 136
 137 char *
 138 format_macaddr(uint8_t *mac)
 139 {
 140         static char str[sizeof("ff:ff:ff:ff:ff:ff ")];
 141
 142         snprintf(str, sizeof(str), "%02x:%02x:%02x:%02x:%02x:%02x",
 143                  mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 144
 145         return str;
 146 }
 147
 148 uint32_t
 149 crc32_file(FILE *fp)
 150 {
 151         static uint32_t *crcvals = NULL;
 152         if (!crcvals) {
 153                 crcvals = malloc(sizeof(*crcvals) * 256);
 154
 155                 for (size_t i = 0; i < 256; ++i) {
 156                         uint32_t c = i;
 157                         for (size_t j = 0; j < 8; ++j)
 158                                 c = (c & 1) ? (0xEDB88320 ^ (c >> 1)) : (c >> 1);
 159                         crcvals[i] = c;
 160                 }
 161         }
 162
 163         uint8_t buf[1024];
 164         size_t len;
 165         uint32_t c = 0xFFFFFFFF;
 166
 167         do {
 168                 len = fread(buf, 1, sizeof(buf), fp);
 169                 for (size_t i = 0; i < len; ++i)
 170                         c = crcvals[(c ^ buf[i]) & 0xFF] ^ (c >> 8);
 171         } while (len == sizeof(buf));
 172
 173         return c ^ 0xFFFFFFFF;
 174 }
 175
 176 bool check_pid_path(int pid, const char *exe)
 177 {
 178         int proc_exe_len;
 179         int exe_len = strlen(exe);
 180
 181 #ifdef __APPLE__
 182         char proc_exe_buf[PROC_PIDPATHINFO_SIZE];
 183
 184         proc_exe_len = proc_pidpath(pid, proc_exe_buf, sizeof(proc_exe_buf));
 185 #else
 186         char proc_exe[32];
 187         char *proc_exe_buf = alloca(exe_len);
 188
 189         sprintf(proc_exe, "/proc/%d/exe", pid);
 190         proc_exe_len = readlink(proc_exe, proc_exe_buf, exe_len);
 191 #endif
 192
 193         if (proc_exe_len != exe_len)
 194                 return false;
 195
 196         return !memcmp(exe, proc_exe_buf, exe_len);
 197 }