diff options
Diffstat (limited to 'src/util/util.c')
| -rw-r--r-- | src/util/util.c | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/src/util/util.c b/src/util/util.c new file mode 100644 index 0000000..b3498df --- /dev/null +++ b/src/util/util.c @@ -0,0 +1,306 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Parts are copied from the linux kernel + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <stdbool.h> + +// CODE FROM LINUX KERNEL START + +#define _U 0x01 /* upper */ +#define _L 0x02 /* lower */ +#define _D 0x04 /* digit */ +#define _C 0x08 /* cntrl */ +#define _P 0x10 /* punct */ +#define _S 0x20 /* white space (space/lf/tab) */ +#define _X 0x40 /* hex digit */ +#define _SP 0x80 /* hard space (0x20) */ + +const unsigned char _ctype[] = { + _C, _C, _C, _C, _C, _C, _C, _C, /* 0-7 */ + _C, _C | _S, _C | _S, _C | _S, _C | _S, _C | _S, _C, _C, /* 8-15 */ + _C, _C, _C, _C, _C, _C, _C, _C, /* 16-23 */ + _C, _C, _C, _C, _C, _C, _C, _C, /* 24-31 */ + _S | _SP, _P, _P, _P, _P, _P, _P, _P, /* 32-39 */ + _P, _P, _P, _P, _P, _P, _P, _P, /* 40-47 */ + _D, _D, _D, _D, _D, _D, _D, _D, /* 48-55 */ + _D, _D, _P, _P, _P, _P, _P, _P, /* 56-63 */ + _P, _U | _X, _U | _X, _U | _X, _U | _X, _U | _X, _U | _X, _U, /* 64-71 */ + _U, _U, _U, _U, _U, _U, _U, _U, /* 72-79 */ + _U, _U, _U, _U, _U, _U, _U, _U, /* 80-87 */ + _U, _U, _U, _P, _P, _P, _P, _P, /* 88-95 */ + _P, _L | _X, _L | _X, _L | _X, _L | _X, _L | _X, _L | _X, _L, /* 96-103 */ + _L, _L, _L, _L, _L, _L, _L, _L, /* 104-111 */ + _L, _L, _L, _L, _L, _L, _L, _L, /* 112-119 */ + _L, _L, _L, _P, _P, _P, _P, _C, /* 120-127 */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 128-143 */ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 144-159 */ + _S | _SP, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, /* 160-175 */ + _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, _P, /* 176-191 */ + _U, _U, _U, _U, _U, _U, _U, _U, _U, _U, _U, _U, _U, _U, _U, _U, /* 192-207 */ + _U, _U, _U, _U, _U, _U, _U, _P, _U, _U, _U, _U, _U, _U, _U, _L, /* 208-223 */ + _L, _L, _L, _L, _L, _L, _L, _L, _L, _L, _L, _L, _L, _L, _L, _L, /* 224-239 */ + _L, _L, _L, _L, _L, _L, _L, _P, _L, _L, _L, _L, _L, _L, _L, _L /* 240-255 */ +}; + +#define __ismask(x) (_ctype[(int)(unsigned char)(x)]) + +#define kernel_isspace(c) ((__ismask(c)&(_S)) != 0) + +static char *skip_spaces(const char *str) +{ + while (kernel_isspace(*str)) + ++str; + return (char *)str; +} + +/* + * Parse a string to get a param value pair. + * You can use " around spaces, but can't escape ". + * Hyphens and underscores equivalent in parameter names. + */ +static char *next_arg(char *args, char **param, char **val) +{ + unsigned int i, equals = 0; + int in_quote = 0, quoted = 0; + char *next; + + if (*args == '"') { + args++; + in_quote = 1; + quoted = 1; + } + + for (i = 0; args[i]; i++) { + if (kernel_isspace(args[i]) && !in_quote) + break; + if (equals == 0) { + if (args[i] == '=') + equals = i; + } + if (args[i] == '"') + in_quote = !in_quote; + } + + *param = args; + if (!equals) + *val = NULL; + else { + args[equals] = '\0'; + *val = args + equals + 1; + + /* Don't include quotes in value. */ + if (**val == '"') { + (*val)++; + if (args[i - 1] == '"') + args[i - 1] = '\0'; + } + } + if (quoted && args[i - 1] == '"') + args[i - 1] = '\0'; + + if (args[i]) { + args[i] = '\0'; + next = args + i + 1; + } else + next = args + i; + + /* Chew up trailing spaces. */ + return skip_spaces(next); +} + +// CODE FROM LINUX KERNEL STOP + +enum EXEC_MODE { + UNDEFINED, + GETARG, + GETARGS, +}; + +static void usage(enum EXEC_MODE enumExecMode, int ret, char *msg) +{ + switch (enumExecMode) { + case UNDEFINED: + fprintf(stderr, "ERROR: 'dracut-util' has to be called via a symlink to the tool name.\n"); + break; + case GETARG: + fprintf(stderr, "ERROR: %s\nUsage: dracut-getarg <KEY>[=[<VALUE>]]\n", msg); + break; + case GETARGS: + fprintf(stderr, "ERROR: %s\nUsage: dracut-getargs <KEY>[=]\n", msg); + break; + } + exit(ret); +} + +#define ARGV0_GETARG "dracut-getarg" +#define ARGV0_GETARGS "dracut-getargs" + +static enum EXEC_MODE get_mode(const char *argv_0) +{ + struct _mode_table { + enum EXEC_MODE mode; + const char *arg; + size_t arg_len; + const char *s_arg; + } modeTable[] = { + {GETARG, ARGV0_GETARG, sizeof(ARGV0_GETARG), "/" ARGV0_GETARG}, + {GETARGS, ARGV0_GETARGS, sizeof(ARGV0_GETARGS), "/" ARGV0_GETARGS}, + {UNDEFINED, NULL, 0, NULL} + }; + int i; + + size_t argv_0_len = strlen(argv_0); + + if (!argv_0_len) + return UNDEFINED; + + for (i = 0; modeTable[i].mode != UNDEFINED; i++) { + if (argv_0_len == (modeTable[i].arg_len - 1)) { + if (strncmp(argv_0, modeTable[i].arg, argv_0_len) == 0) { + return modeTable[i].mode; + } + } + + if (modeTable[i].arg_len > argv_0_len) + continue; + + if (strncmp(argv_0 + argv_0_len - modeTable[i].arg_len, modeTable[i].s_arg, modeTable[i].arg_len) == 0) + return modeTable[i].mode; + } + return UNDEFINED; +} + +static int getarg(int argc, char **argv) +{ + char *search_key; + char *search_value; + char *end_value = NULL; + bool bool_value = false; + char *cmdline = NULL; + + char *p = getenv("CMDLINE"); + if (p == NULL) { + usage(GETARG, EXIT_FAILURE, "CMDLINE env not set"); + } + cmdline = strdup(p); + + if (argc != 2) { + usage(GETARG, EXIT_FAILURE, "Number of arguments invalid"); + } + + search_key = argv[1]; + + search_value = strchr(argv[1], '='); + if (search_value != NULL) { + *search_value = 0; + search_value++; + if (*search_value == 0) + search_value = NULL; + } + + if (strlen(search_key) == 0) + usage(GETARG, EXIT_FAILURE, "search key undefined"); + + do { + char *key = NULL, *value = NULL; + cmdline = next_arg(cmdline, &key, &value); + if (strcmp(key, search_key) == 0) { + if (value) { + end_value = value; + bool_value = -1; + } else { + end_value = NULL; + bool_value = true; + } + } + } while (cmdline[0]); + + if (search_value) { + if (end_value && strcmp(end_value, search_value) == 0) { + return EXIT_SUCCESS; + } + return EXIT_FAILURE; + } + + if (end_value) { + // includes "=0" + puts(end_value); + return EXIT_SUCCESS; + } + + if (bool_value) { + return EXIT_SUCCESS; + } + + return EXIT_FAILURE; +} + +static int getargs(int argc, char **argv) +{ + char *search_key; + char *search_value; + bool found_value = false; + char *cmdline = NULL; + + char *p = getenv("CMDLINE"); + if (p == NULL) { + usage(GETARGS, EXIT_FAILURE, "CMDLINE env not set"); + } + cmdline = strdup(p); + + if (argc != 2) { + usage(GETARGS, EXIT_FAILURE, "Number of arguments invalid"); + } + + search_key = argv[1]; + + search_value = strchr(argv[1], '='); + if (search_value != NULL) { + *search_value = 0; + search_value++; + if (*search_value == 0) + search_value = NULL; + } + + if (strlen(search_key) == 0) + usage(GETARGS, EXIT_FAILURE, "search key undefined"); + + do { + char *key = NULL, *value = NULL; + cmdline = next_arg(cmdline, &key, &value); + if (strcmp(key, search_key) == 0) { + if (search_value) { + if (strcmp(value, search_value) == 0) { + printf("%s\n", value); + found_value = true; + } + } else { + if (value) { + printf("%s\n", value); + } else { + puts(key); + } + found_value = true; + } + } + } while (cmdline[0]); + return found_value ? EXIT_SUCCESS : EXIT_FAILURE; +} + +int main(int argc, char **argv) +{ + switch (get_mode(argv[0])) { + case UNDEFINED: + usage(UNDEFINED, EXIT_FAILURE, NULL); + break; + case GETARG: + return getarg(argc, argv); + case GETARGS: + return getargs(argc, argv); + } + + return EXIT_FAILURE; +} |