1 /* SPDX-License-Identifier: BSD-2-Clause */ 2 /* 3 * dhcpcd - DHCP client daemon 4 * Copyright (c) 2006-2021 Roy Marples <roy@marples.name> 5 * All rights reserved 6 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/stat.h> 30 #include <sys/statvfs.h> 31 32 #include <ctype.h> 33 #include <errno.h> 34 #include <fcntl.h> 35 #include <stdio.h> 36 #include <stdlib.h> 37 #include <string.h> 38 39 #include "common.h" 40 #include "dhcpcd.h" 41 #include "if-options.h" 42 43 const char * 44 hwaddr_ntoa(const void *hwaddr, size_t hwlen, char *buf, size_t buflen) 45 { 46 const unsigned char *hp, *ep; 47 char *p; 48 49 if (buf == NULL || hwlen == 0) 50 return NULL; 51 52 if (hwlen * 3 > buflen) { 53 errno = ENOBUFS; 54 return NULL; 55 } 56 57 hp = hwaddr; 58 ep = hp + hwlen; 59 p = buf; 60 61 while (hp < ep) { 62 if (hp != hwaddr) 63 *p ++= ':'; 64 p += snprintf(p, 3, "%.2x", *hp++); 65 } 66 *p ++= '\0'; 67 return buf; 68 } 69 70 size_t 71 hwaddr_aton(uint8_t *buffer, const char *addr) 72 { 73 char c[3]; 74 const char *p = addr; 75 uint8_t *bp = buffer; 76 size_t len = 0; 77 78 c[2] = '\0'; 79 while (*p != '\0') { 80 /* Skip separators */ 81 c[0] = *p++; 82 switch (c[0]) { 83 case '\n': /* long duid split on lines */ 84 case ':': /* typical mac address */ 85 case '-': /* uuid */ 86 continue; 87 } 88 c[1] = *p++; 89 /* Ensure that digits are hex */ 90 if (isxdigit((unsigned char)c[0]) == 0 || 91 isxdigit((unsigned char)c[1]) == 0) 92 { 93 errno = EINVAL; 94 return 0; 95 } 96 /* We should have at least two entries 00:01 */ 97 if (len == 0 && *p == '\0') { 98 errno = EINVAL; 99 return 0; 100 } 101 if (bp) 102 *bp++ = (uint8_t)strtol(c, NULL, 16); 103 len++; 104 } 105 return len; 106 } 107 108 ssize_t 109 readfile(const char *file, void *data, size_t len) 110 { 111 int fd; 112 ssize_t bytes; 113 114 fd = open(file, O_RDONLY); 115 if (fd == -1) 116 return -1; 117 bytes = read(fd, data, len); 118 close(fd); 119 if ((size_t)bytes == len) { 120 errno = ENOBUFS; 121 return -1; 122 } 123 return bytes; 124 } 125 126 ssize_t 127 writefile(const char *file, mode_t mode, const void *data, size_t len) 128 { 129 int fd; 130 ssize_t bytes; 131 132 fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, mode); 133 if (fd == -1) 134 return -1; 135 bytes = write(fd, data, len); 136 close(fd); 137 return bytes; 138 } 139 140 int 141 filemtime(const char *file, time_t *time) 142 { 143 struct stat st; 144 145 if (stat(file, &st) == -1) 146 return -1; 147 *time = st.st_mtime; 148 return 0; 149 } 150 151 /* Handy routine to read very long lines in text files. 152 * This means we read the whole line and avoid any nasty buffer overflows. 153 * We strip leading space and avoid comment lines, making the code that calls 154 * us smaller. */ 155 char * 156 get_line(char ** __restrict buf, ssize_t * __restrict buflen) 157 { 158 char *p, *c; 159 bool quoted; 160 161 do { 162 p = *buf; 163 if (*buf == NULL) 164 return NULL; 165 c = memchr(*buf, '\n', (size_t)*buflen); 166 if (c == NULL) { 167 c = memchr(*buf, '\0', (size_t)*buflen); 168 if (c == NULL) 169 return NULL; 170 *buflen = c - *buf; 171 *buf = NULL; 172 } else { 173 *c++ = '\0'; 174 *buflen -= c - *buf; 175 *buf = c; 176 } 177 for (; *p == ' ' || *p == '\t'; p++) 178 ; 179 } while (*p == '\0' || *p == '\n' || *p == '#' || *p == ';'); 180 181 /* Strip embedded comments unless in a quoted string or escaped */ 182 quoted = false; 183 for (c = p; *c != '\0'; c++) { 184 if (*c == '\\') { 185 c++; /* escaped */ 186 continue; 187 } 188 if (*c == '"') 189 quoted = !quoted; 190 else if (*c == '#' && !quoted) { 191 *c = '\0'; 192 break; 193 } 194 } 195 return p; 196 } 197 198 199 int 200 is_root_local(void) 201 { 202 #ifdef ST_LOCAL 203 struct statvfs vfs; 204 205 if (statvfs("/", &vfs) == -1) 206 return -1; 207 return vfs.f_flag & ST_LOCAL ? 1 : 0; 208 #else 209 errno = ENOTSUP; 210 return -1; 211 #endif 212 } 213