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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /lib/argv_split.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/argv_split.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/lib/argv_split.c b/lib/argv_split.c new file mode 100644 index 000000000..1a19a0a93 --- /dev/null +++ b/lib/argv_split.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Helper function for splitting a string into an argv-like array. + */ + +#include <linux/kernel.h> +#include <linux/ctype.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/export.h> + +static int count_argc(const char *str) +{ + int count = 0; + bool was_space; + + for (was_space = true; *str; str++) { + if (isspace(*str)) { + was_space = true; + } else if (was_space) { + was_space = false; + count++; + } + } + + return count; +} + +/** + * argv_free - free an argv + * @argv - the argument vector to be freed + * + * Frees an argv and the strings it points to. + */ +void argv_free(char **argv) +{ + argv--; + kfree(argv[0]); + kfree(argv); +} +EXPORT_SYMBOL(argv_free); + +/** + * argv_split - split a string at whitespace, returning an argv + * @gfp: the GFP mask used to allocate memory + * @str: the string to be split + * @argcp: returned argument count + * + * Returns an array of pointers to strings which are split out from + * @str. This is performed by strictly splitting on white-space; no + * quote processing is performed. Multiple whitespace characters are + * considered to be a single argument separator. The returned array + * is always NULL-terminated. Returns NULL on memory allocation + * failure. + * + * The source string at `str' may be undergoing concurrent alteration via + * userspace sysctl activity (at least). The argv_split() implementation + * attempts to handle this gracefully by taking a local copy to work on. + */ +char **argv_split(gfp_t gfp, const char *str, int *argcp) +{ + char *argv_str; + bool was_space; + char **argv, **argv_ret; + int argc; + + argv_str = kstrndup(str, KMALLOC_MAX_SIZE - 1, gfp); + if (!argv_str) + return NULL; + + argc = count_argc(argv_str); + argv = kmalloc_array(argc + 2, sizeof(*argv), gfp); + if (!argv) { + kfree(argv_str); + return NULL; + } + + *argv = argv_str; + argv_ret = ++argv; + for (was_space = true; *argv_str; argv_str++) { + if (isspace(*argv_str)) { + was_space = true; + *argv_str = 0; + } else if (was_space) { + was_space = false; + *argv++ = argv_str; + } + } + *argv = NULL; + + if (argcp) + *argcp = argc; + return argv_ret; +} +EXPORT_SYMBOL(argv_split); |