1 /* 2 * (C) Copyright 2000-2008 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8 /* 9 * Command line user interface to firmware (=U-Boot) environment. 10 * 11 * Implements: 12 * fw_printenv [ -a key ] [[ -n name ] | [ name ... ]] 13 * - prints the value of a single environment variable 14 * "name", the ``name=value'' pairs of one or more 15 * environment variables "name", or the whole 16 * environment if no names are specified. 17 * fw_setenv [ -a key ] name [ value ... ] 18 * - If a name without any values is given, the variable 19 * with this name is deleted from the environment; 20 * otherwise, all "value" arguments are concatenated, 21 * separated by single blank characters, and the 22 * resulting string is assigned to the environment 23 * variable "name" 24 * 25 * If '-a key' is specified, the env block is encrypted with AES 128 CBC. 26 * The 'key' argument is in the format of 32 hexadecimal numbers (16 bytes 27 * of AES key), eg. '-a aabbccddeeff00112233445566778899'. 28 */ 29 30 #include <fcntl.h> 31 #include <getopt.h> 32 #include <stdio.h> 33 #include <string.h> 34 #include <stdlib.h> 35 #include <sys/file.h> 36 #include <unistd.h> 37 #include "fw_env.h" 38 39 #define CMD_PRINTENV "fw_printenv" 40 #define CMD_SETENV "fw_setenv" 41 42 static struct option long_options[] = { 43 {"script", required_argument, NULL, 's'}, 44 {"help", no_argument, NULL, 'h'}, 45 {NULL, 0, NULL, 0} 46 }; 47 48 struct printenv_args printenv_args; 49 struct setenv_args setenv_args; 50 51 void usage(void) 52 { 53 54 fprintf(stderr, "fw_printenv/fw_setenv, " 55 "a command line interface to U-Boot environment\n\n" 56 #ifndef CONFIG_FILE 57 "usage:\tfw_printenv [-a key] [-n] [variable name]\n" 58 "\tfw_setenv [-a key] [variable name] [variable value]\n" 59 #else 60 "usage:\tfw_printenv [-c /my/fw_env.config] [-a key] [-n] [variable name]\n" 61 "\tfw_setenv [-c /my/fw_env.config] [-a key] [variable name] [variable value]\n" 62 #endif 63 "\tfw_setenv -s [ file ]\n" 64 "\tfw_setenv -s - < [ file ]\n\n" 65 "The file passed as argument contains only pairs " 66 "name / value\n" 67 "Example:\n" 68 "# Any line starting with # is treated as comment\n" 69 "\n" 70 "\t netdev eth0\n" 71 "\t kernel_addr 400000\n" 72 "\t var1\n" 73 "\t var2 The quick brown fox jumps over the " 74 "lazy dog\n" 75 "\n" 76 "A variable without value will be dropped. It is possible\n" 77 "to put any number of spaces between the fields, but any\n" 78 "space inside the value is treated as part of the value " 79 "itself.\n\n" 80 ); 81 } 82 83 int parse_printenv_args(int argc, char *argv[]) 84 { 85 int c; 86 87 while ((c = getopt_long (argc, argv, "a:c:ns:h", 88 long_options, NULL)) != EOF) { 89 switch (c) { 90 case 'a': 91 /* AES key, handled later */ 92 break; 93 case 'c': 94 /* handled later */ 95 break; 96 case 'n': 97 /* handled in fw_printenv */ 98 break; 99 case 'h': 100 usage(); 101 exit(EXIT_SUCCESS); 102 break; 103 default: /* '?' */ 104 usage(); 105 exit(EXIT_FAILURE); 106 break; 107 } 108 } 109 return 0; 110 } 111 112 int parse_setenv_args(int argc, char *argv[]) 113 { 114 int c; 115 116 while ((c = getopt_long (argc, argv, "a:c:ns:h", 117 long_options, NULL)) != EOF) { 118 switch (c) { 119 case 'a': 120 /* AES key, handled later */ 121 break; 122 case 'c': 123 /* handled later */ 124 break; 125 case 's': 126 setenv_args.script_file = optarg; 127 break; 128 case 'h': 129 usage(); 130 exit(EXIT_SUCCESS); 131 break; 132 default: /* '?' */ 133 usage(); 134 exit(EXIT_FAILURE); 135 break; 136 } 137 } 138 return 0; 139 } 140 141 int main(int argc, char *argv[]) 142 { 143 char *cmdname = *argv; 144 const char *lockname = "/var/lock/" CMD_PRINTENV ".lock"; 145 int lockfd = -1; 146 int retval = EXIT_SUCCESS; 147 148 if (strrchr(cmdname, '/') != NULL) 149 cmdname = strrchr(cmdname, '/') + 1; 150 151 if (strcmp(cmdname, CMD_PRINTENV) == 0) { 152 if (parse_printenv_args(argc, argv)) 153 exit(EXIT_FAILURE); 154 } else if (strcmp(cmdname, CMD_SETENV) == 0) { 155 if (parse_setenv_args(argc, argv)) 156 exit(EXIT_FAILURE); 157 } else { 158 fprintf(stderr, 159 "Identity crisis - may be called as `%s' or as `%s' but not as `%s'\n", 160 CMD_PRINTENV, CMD_SETENV, cmdname); 161 exit(EXIT_FAILURE); 162 } 163 164 lockfd = open(lockname, O_WRONLY | O_CREAT | O_TRUNC, 0666); 165 if (-1 == lockfd) { 166 fprintf(stderr, "Error opening lock file %s\n", lockname); 167 return EXIT_FAILURE; 168 } 169 170 if (-1 == flock(lockfd, LOCK_EX)) { 171 fprintf(stderr, "Error locking file %s\n", lockname); 172 close(lockfd); 173 return EXIT_FAILURE; 174 } 175 176 if (strcmp(cmdname, CMD_PRINTENV) == 0) { 177 if (fw_printenv(argc, argv) != 0) 178 retval = EXIT_FAILURE; 179 } else if (strcmp(cmdname, CMD_SETENV) == 0) { 180 if (!setenv_args.script_file) { 181 if (fw_setenv(argc, argv) != 0) 182 retval = EXIT_FAILURE; 183 } else { 184 if (fw_parse_script(setenv_args.script_file) != 0) 185 retval = EXIT_FAILURE; 186 } 187 } 188 189 flock(lockfd, LOCK_UN); 190 close(lockfd); 191 return retval; 192 } 193