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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:42:50 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:42:50 +0000 |
commit | 8cb83eee5a58b1fad74c34094ce3afb9e430b5a4 (patch) | |
tree | a9b2e7baeca1be40eb734371e3c8b11b02294497 /lib/mangle.c | |
parent | Initial commit. (diff) | |
download | util-linux-8cb83eee5a58b1fad74c34094ce3afb9e430b5a4.tar.xz util-linux-8cb83eee5a58b1fad74c34094ce3afb9e430b5a4.zip |
Adding upstream version 2.33.1.upstream/2.33.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/mangle.c')
-rw-r--r-- | lib/mangle.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/lib/mangle.c b/lib/mangle.c new file mode 100644 index 0000000..b61c57f --- /dev/null +++ b/lib/mangle.c @@ -0,0 +1,168 @@ +/* + * Functions for \oct encoding used in mtab/fstab/swaps/etc. + * + * Based on code from mount(8). + * + * Copyright (C) 2010 Karel Zak <kzak@redhat.com> + */ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <ctype.h> + +#include "mangle.h" +#include "c.h" + +#define isoctal(a) (((a) & ~7) == '0') + +#define from_hex(c) (isdigit(c) ? c - '0' : tolower(c) - 'a' + 10) + +#define is_unwanted_char(x) (strchr(" \t\n\\", (unsigned int) x) != NULL) + + +char *mangle(const char *s) +{ + char *ss, *sp; + + if (!s) + return NULL; + + ss = sp = malloc(4 * strlen(s) + 1); + if (!sp) + return NULL; + while(1) { + if (!*s) { + *sp = '\0'; + break; + } + if (is_unwanted_char(*s)) { + *sp++ = '\\'; + *sp++ = '0' + ((*s & 0300) >> 6); + *sp++ = '0' + ((*s & 070) >> 3); + *sp++ = '0' + (*s & 07); + } else + *sp++ = *s; + s++; + } + return ss; +} + + +void unmangle_to_buffer(const char *s, char *buf, size_t len) +{ + size_t sz = 0; + + if (!s) + return; + + while(*s && sz < len - 1) { + if (*s == '\\' && sz + 3 < len - 1 && isoctal(s[1]) && + isoctal(s[2]) && isoctal(s[3])) { + + *buf++ = 64*(s[1] & 7) + 8*(s[2] & 7) + (s[3] & 7); + s += 4; + sz += 4; + } else { + *buf++ = *s++; + sz++; + } + } + *buf = '\0'; +} + +size_t unhexmangle_to_buffer(const char *s, char *buf, size_t len) +{ + size_t sz = 0; + const char *buf0 = buf; + + if (!s) + return 0; + + while(*s && sz < len - 1) { + if (*s == '\\' && sz + 3 < len - 1 && s[1] == 'x' && + isxdigit(s[2]) && isxdigit(s[3])) { + + *buf++ = from_hex(s[2]) << 4 | from_hex(s[3]); + s += 4; + sz += 4; + } else { + *buf++ = *s++; + sz++; + } + } + *buf = '\0'; + return buf - buf0 + 1; +} + +static inline const char *skip_nonspaces(const char *s) +{ + while (*s && !(*s == ' ' || *s == '\t')) + s++; + return s; +} + +/* + * Returns mallocated buffer or NULL in case of error. + */ +char *unmangle(const char *s, const char **end) +{ + char *buf; + const char *e; + size_t sz; + + if (!s) + return NULL; + + e = skip_nonspaces(s); + sz = e - s + 1; + + if (end) + *end = e; + if (e == s) + return NULL; /* empty string */ + + buf = malloc(sz); + if (!buf) + return NULL; + + unmangle_to_buffer(s, buf, sz); + return buf; +} + +#ifdef TEST_PROGRAM_MANGLE +#include <errno.h> +int main(int argc, char *argv[]) +{ + char *p = NULL; + if (argc < 3) { + fprintf(stderr, "usage: %s --mangle|unmangle <string>\n", + program_invocation_short_name); + return EXIT_FAILURE; + } + + if (!strcmp(argv[1], "--mangle")) { + p = mangle(argv[2]); + printf("mangled: '%s'\n", p); + free(p); + } + + else if (!strcmp(argv[1], "--unmangle")) { + char *x = unmangle(argv[2], NULL); + + if (x) { + printf("unmangled: '%s'\n", x); + free(x); + } + + x = strdup(argv[2]); + unmangle_to_buffer(x, x, strlen(x) + 1); + + if (x) { + printf("self-unmangled: '%s'\n", x); + free(x); + } + } + + return EXIT_SUCCESS; +} +#endif /* TEST_PROGRAM_MANGLE */ |