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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:25:50 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:25:50 +0000 |
commit | 19f4f86bfed21c5326ed2acebe1163f3a83e832b (patch) | |
tree | d59b9989ce55ed23693e80974d94c856f1c2c8b1 /src/basic/proc-cmdline.c | |
parent | Initial commit. (diff) | |
download | systemd-upstream.tar.xz systemd-upstream.zip |
Adding upstream version 241.upstream/241upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/basic/proc-cmdline.c')
-rw-r--r-- | src/basic/proc-cmdline.c | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/src/basic/proc-cmdline.c b/src/basic/proc-cmdline.c new file mode 100644 index 0000000..1670001 --- /dev/null +++ b/src/basic/proc-cmdline.c @@ -0,0 +1,363 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <stdbool.h> +#include <stddef.h> +#include <string.h> + +#include "alloc-util.h" +#include "extract-word.h" +#include "fileio.h" +#include "macro.h" +#include "parse-util.h" +#include "proc-cmdline.h" +#include "process-util.h" +#include "special.h" +#include "string-util.h" +#include "util.h" +#include "virt.h" + +int proc_cmdline(char **ret) { + const char *e; + assert(ret); + + /* For testing purposes it is sometimes useful to be able to override what we consider /proc/cmdline to be */ + e = secure_getenv("SYSTEMD_PROC_CMDLINE"); + if (e) { + char *m; + + m = strdup(e); + if (!m) + return -ENOMEM; + + *ret = m; + return 0; + } + + if (detect_container() > 0) + return get_process_cmdline(1, 0, false, ret); + else + return read_one_line_file("/proc/cmdline", ret); +} + +static int proc_cmdline_extract_first(const char **p, char **ret_word, ProcCmdlineFlags flags) { + const char *q = *p; + int r; + + for (;;) { + _cleanup_free_ char *word = NULL; + const char *c; + + r = extract_first_word(&q, &word, NULL, EXTRACT_QUOTES|EXTRACT_RELAX); + if (r < 0) + return r; + if (r == 0) + break; + + /* Filter out arguments that are intended only for the initrd */ + c = startswith(word, "rd."); + if (c) { + if (!in_initrd()) + continue; + + if (FLAGS_SET(flags, PROC_CMDLINE_STRIP_RD_PREFIX)) { + r = free_and_strdup(&word, c); + if (r < 0) + return r; + } + + } else if (FLAGS_SET(flags, PROC_CMDLINE_RD_STRICT) && in_initrd()) + continue; /* And optionally filter out arguments that are intended only for the host */ + + *p = q; + *ret_word = TAKE_PTR(word); + return 1; + } + + *p = q; + *ret_word = NULL; + return 0; +} + +int proc_cmdline_parse_given(const char *line, proc_cmdline_parse_t parse_item, void *data, ProcCmdlineFlags flags) { + const char *p; + int r; + + assert(parse_item); + + /* The PROC_CMDLINE_VALUE_OPTIONAL flag doesn't really make sense for proc_cmdline_parse(), let's make this + * clear. */ + assert(!FLAGS_SET(flags, PROC_CMDLINE_VALUE_OPTIONAL)); + + p = line; + for (;;) { + _cleanup_free_ char *word = NULL; + char *value; + + r = proc_cmdline_extract_first(&p, &word, flags); + if (r < 0) + return r; + if (r == 0) + break; + + value = strchr(word, '='); + if (value) + *(value++) = 0; + + r = parse_item(word, value, data); + if (r < 0) + return r; + } + + return 0; +} + +int proc_cmdline_parse(proc_cmdline_parse_t parse_item, void *data, ProcCmdlineFlags flags) { + _cleanup_free_ char *line = NULL; + int r; + + assert(parse_item); + + r = proc_cmdline(&line); + if (r < 0) + return r; + + return proc_cmdline_parse_given(line, parse_item, data, flags); +} + +static bool relaxed_equal_char(char a, char b) { + return a == b || + (a == '_' && b == '-') || + (a == '-' && b == '_'); +} + +char *proc_cmdline_key_startswith(const char *s, const char *prefix) { + assert(s); + assert(prefix); + + /* Much like startswith(), but considers "-" and "_" the same */ + + for (; *prefix != 0; s++, prefix++) + if (!relaxed_equal_char(*s, *prefix)) + return NULL; + + return (char*) s; +} + +bool proc_cmdline_key_streq(const char *x, const char *y) { + assert(x); + assert(y); + + /* Much like streq(), but considers "-" and "_" the same */ + + for (; *x != 0 || *y != 0; x++, y++) + if (!relaxed_equal_char(*x, *y)) + return false; + + return true; +} + +int proc_cmdline_get_key(const char *key, ProcCmdlineFlags flags, char **ret_value) { + _cleanup_free_ char *line = NULL, *ret = NULL; + bool found = false; + const char *p; + int r; + + /* Looks for a specific key on the kernel command line. Supports three modes: + * + * a) The "ret_value" parameter is used. In this case a parameter beginning with the "key" string followed by + * "=" is searched for, and the value following it is returned in "ret_value". + * + * b) as above, but the PROC_CMDLINE_VALUE_OPTIONAL flag is set. In this case if the key is found as a separate + * word (i.e. not followed by "=" but instead by whitespace or the end of the command line), then this is + * also accepted, and "value" is returned as NULL. + * + * c) The "ret_value" parameter is NULL. In this case a search for the exact "key" parameter is performed. + * + * In all three cases, > 0 is returned if the key is found, 0 if not. */ + + if (isempty(key)) + return -EINVAL; + + if (FLAGS_SET(flags, PROC_CMDLINE_VALUE_OPTIONAL) && !ret_value) + return -EINVAL; + + r = proc_cmdline(&line); + if (r < 0) + return r; + + p = line; + for (;;) { + _cleanup_free_ char *word = NULL; + + r = proc_cmdline_extract_first(&p, &word, flags); + if (r < 0) + return r; + if (r == 0) + break; + + if (ret_value) { + const char *e; + + e = proc_cmdline_key_startswith(word, key); + if (!e) + continue; + + if (*e == '=') { + r = free_and_strdup(&ret, e+1); + if (r < 0) + return r; + + found = true; + + } else if (*e == 0 && FLAGS_SET(flags, PROC_CMDLINE_VALUE_OPTIONAL)) + found = true; + + } else { + if (streq(word, key)) { + found = true; + break; /* we found what we were looking for */ + } + } + } + + if (ret_value) + *ret_value = TAKE_PTR(ret); + + return found; +} + +int proc_cmdline_get_bool(const char *key, bool *ret) { + _cleanup_free_ char *v = NULL; + int r; + + assert(ret); + + r = proc_cmdline_get_key(key, PROC_CMDLINE_VALUE_OPTIONAL, &v); + if (r < 0) + return r; + if (r == 0) { + *ret = false; + return 0; + } + + if (v) { /* parameter passed */ + r = parse_boolean(v); + if (r < 0) + return r; + *ret = r; + } else /* no parameter passed */ + *ret = true; + + return 1; +} + +int proc_cmdline_get_key_many_internal(ProcCmdlineFlags flags, ...) { + _cleanup_free_ char *line = NULL; + const char *p; + va_list ap; + int r, ret = 0; + + /* The PROC_CMDLINE_VALUE_OPTIONAL flag doesn't really make sense for proc_cmdline_get_key_many(), let's make + * this clear. */ + assert(!FLAGS_SET(flags, PROC_CMDLINE_VALUE_OPTIONAL)); + + /* This call may clobber arguments on failure! */ + + r = proc_cmdline(&line); + if (r < 0) + return r; + + p = line; + for (;;) { + _cleanup_free_ char *word = NULL; + + r = proc_cmdline_extract_first(&p, &word, flags); + if (r < 0) + return r; + if (r == 0) + break; + + va_start(ap, flags); + + for (;;) { + char **v; + const char *k, *e; + + k = va_arg(ap, const char*); + if (!k) + break; + + assert_se(v = va_arg(ap, char**)); + + e = proc_cmdline_key_startswith(word, k); + if (e && *e == '=') { + r = free_and_strdup(v, e + 1); + if (r < 0) { + va_end(ap); + return r; + } + + ret++; + } + } + + va_end(ap); + } + + return ret; +} + +int shall_restore_state(void) { + bool ret; + int r; + + r = proc_cmdline_get_bool("systemd.restore_state", &ret); + if (r < 0) + return r; + + return r > 0 ? ret : true; +} + +static const char * const rlmap[] = { + "emergency", SPECIAL_EMERGENCY_TARGET, + "-b", SPECIAL_EMERGENCY_TARGET, + "rescue", SPECIAL_RESCUE_TARGET, + "single", SPECIAL_RESCUE_TARGET, + "-s", SPECIAL_RESCUE_TARGET, + "s", SPECIAL_RESCUE_TARGET, + "S", SPECIAL_RESCUE_TARGET, + "1", SPECIAL_RESCUE_TARGET, + "2", SPECIAL_MULTI_USER_TARGET, + "3", SPECIAL_MULTI_USER_TARGET, + "4", SPECIAL_MULTI_USER_TARGET, + "5", SPECIAL_GRAPHICAL_TARGET, + NULL +}; + +static const char * const rlmap_initrd[] = { + "emergency", SPECIAL_EMERGENCY_TARGET, + "rescue", SPECIAL_RESCUE_TARGET, + NULL +}; + +const char* runlevel_to_target(const char *word) { + const char * const *rlmap_ptr; + size_t i; + + if (!word) + return NULL; + + if (in_initrd()) { + word = startswith(word, "rd."); + if (!word) + return NULL; + } + + rlmap_ptr = in_initrd() ? rlmap_initrd : rlmap; + + for (i = 0; rlmap_ptr[i]; i += 2) + if (streq(word, rlmap_ptr[i])) + return rlmap_ptr[i+1]; + + return NULL; +} |