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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
commit | b750101eb236130cf056c675997decbac904cc49 (patch) | |
tree | a5df1a06754bdd014cb975c051c83b01c9a97532 /src/basic/escape.c | |
parent | Initial commit. (diff) | |
download | systemd-upstream.tar.xz systemd-upstream.zip |
Adding upstream version 252.22.upstream/252.22upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/basic/escape.c | 576 |
1 files changed, 576 insertions, 0 deletions
diff --git a/src/basic/escape.c b/src/basic/escape.c new file mode 100644 index 0000000..d2cb1c7 --- /dev/null +++ b/src/basic/escape.c @@ -0,0 +1,576 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <stdlib.h> +#include <string.h> + +#include "alloc-util.h" +#include "escape.h" +#include "hexdecoct.h" +#include "macro.h" +#include "strv.h" +#include "utf8.h" + +int cescape_char(char c, char *buf) { + char *buf_old = buf; + + /* Needs space for 4 characters in the buffer */ + + switch (c) { + + case '\a': + *(buf++) = '\\'; + *(buf++) = 'a'; + break; + case '\b': + *(buf++) = '\\'; + *(buf++) = 'b'; + break; + case '\f': + *(buf++) = '\\'; + *(buf++) = 'f'; + break; + case '\n': + *(buf++) = '\\'; + *(buf++) = 'n'; + break; + case '\r': + *(buf++) = '\\'; + *(buf++) = 'r'; + break; + case '\t': + *(buf++) = '\\'; + *(buf++) = 't'; + break; + case '\v': + *(buf++) = '\\'; + *(buf++) = 'v'; + break; + case '\\': + *(buf++) = '\\'; + *(buf++) = '\\'; + break; + case '"': + *(buf++) = '\\'; + *(buf++) = '"'; + break; + case '\'': + *(buf++) = '\\'; + *(buf++) = '\''; + break; + + default: + /* For special chars we prefer octal over + * hexadecimal encoding, simply because glib's + * g_strescape() does the same */ + if ((c < ' ') || (c >= 127)) { + *(buf++) = '\\'; + *(buf++) = octchar((unsigned char) c >> 6); + *(buf++) = octchar((unsigned char) c >> 3); + *(buf++) = octchar((unsigned char) c); + } else + *(buf++) = c; + break; + } + + return buf - buf_old; +} + +char* cescape_length(const char *s, size_t n) { + const char *f; + char *r, *t; + + assert(s || n == 0); + + /* Does C style string escaping. May be reversed with + * cunescape(). */ + + r = new(char, n*4 + 1); + if (!r) + return NULL; + + for (f = s, t = r; f < s + n; f++) + t += cescape_char(*f, t); + + *t = 0; + + return r; +} + +char* cescape(const char *s) { + assert(s); + + return cescape_length(s, strlen(s)); +} + +int cunescape_one(const char *p, size_t length, char32_t *ret, bool *eight_bit, bool accept_nul) { + int r = 1; + + assert(p); + assert(ret); + + /* Unescapes C style. Returns the unescaped character in ret. + * Sets *eight_bit to true if the escaped sequence either fits in + * one byte in UTF-8 or is a non-unicode literal byte and should + * instead be copied directly. + */ + + if (length != SIZE_MAX && length < 1) + return -EINVAL; + + switch (p[0]) { + + case 'a': + *ret = '\a'; + break; + case 'b': + *ret = '\b'; + break; + case 'f': + *ret = '\f'; + break; + case 'n': + *ret = '\n'; + break; + case 'r': + *ret = '\r'; + break; + case 't': + *ret = '\t'; + break; + case 'v': + *ret = '\v'; + break; + case '\\': + *ret = '\\'; + break; + case '"': + *ret = '"'; + break; + case '\'': + *ret = '\''; + break; + + case 's': + /* This is an extension of the XDG syntax files */ + *ret = ' '; + break; + + case 'x': { + /* hexadecimal encoding */ + int a, b; + + if (length != SIZE_MAX && length < 3) + return -EINVAL; + + a = unhexchar(p[1]); + if (a < 0) + return -EINVAL; + + b = unhexchar(p[2]); + if (b < 0) + return -EINVAL; + + /* Don't allow NUL bytes */ + if (a == 0 && b == 0 && !accept_nul) + return -EINVAL; + + *ret = (a << 4U) | b; + *eight_bit = true; + r = 3; + break; + } + + case 'u': { + /* C++11 style 16bit unicode */ + + int a[4]; + size_t i; + uint32_t c; + + if (length != SIZE_MAX && length < 5) + return -EINVAL; + + for (i = 0; i < 4; i++) { + a[i] = unhexchar(p[1 + i]); + if (a[i] < 0) + return a[i]; + } + + c = ((uint32_t) a[0] << 12U) | ((uint32_t) a[1] << 8U) | ((uint32_t) a[2] << 4U) | (uint32_t) a[3]; + + /* Don't allow 0 chars */ + if (c == 0 && !accept_nul) + return -EINVAL; + + *ret = c; + r = 5; + break; + } + + case 'U': { + /* C++11 style 32bit unicode */ + + int a[8]; + size_t i; + char32_t c; + + if (length != SIZE_MAX && length < 9) + return -EINVAL; + + for (i = 0; i < 8; i++) { + a[i] = unhexchar(p[1 + i]); + if (a[i] < 0) + return a[i]; + } + + c = ((uint32_t) a[0] << 28U) | ((uint32_t) a[1] << 24U) | ((uint32_t) a[2] << 20U) | ((uint32_t) a[3] << 16U) | + ((uint32_t) a[4] << 12U) | ((uint32_t) a[5] << 8U) | ((uint32_t) a[6] << 4U) | (uint32_t) a[7]; + + /* Don't allow 0 chars */ + if (c == 0 && !accept_nul) + return -EINVAL; + + /* Don't allow invalid code points */ + if (!unichar_is_valid(c)) + return -EINVAL; + + *ret = c; + r = 9; + break; + } + + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': { + /* octal encoding */ + int a, b, c; + char32_t m; + + if (length != SIZE_MAX && length < 3) + return -EINVAL; + + a = unoctchar(p[0]); + if (a < 0) + return -EINVAL; + + b = unoctchar(p[1]); + if (b < 0) + return -EINVAL; + + c = unoctchar(p[2]); + if (c < 0) + return -EINVAL; + + /* don't allow NUL bytes */ + if (a == 0 && b == 0 && c == 0 && !accept_nul) + return -EINVAL; + + /* Don't allow bytes above 255 */ + m = ((uint32_t) a << 6U) | ((uint32_t) b << 3U) | (uint32_t) c; + if (m > 255) + return -EINVAL; + + *ret = m; + *eight_bit = true; + r = 3; + break; + } + + default: + return -EINVAL; + } + + return r; +} + +ssize_t cunescape_length_with_prefix(const char *s, size_t length, const char *prefix, UnescapeFlags flags, char **ret) { + _cleanup_free_ char *ans = NULL; + char *t; + const char *f; + size_t pl; + int r; + + assert(s); + assert(ret); + + /* Undoes C style string escaping, and optionally prefixes it. */ + + pl = strlen_ptr(prefix); + + ans = new(char, pl+length+1); + if (!ans) + return -ENOMEM; + + if (prefix) + memcpy(ans, prefix, pl); + + for (f = s, t = ans + pl; f < s + length; f++) { + size_t remaining; + bool eight_bit = false; + char32_t u; + + remaining = s + length - f; + assert(remaining > 0); + + if (*f != '\\') { + /* A literal, copy verbatim */ + *(t++) = *f; + continue; + } + + if (remaining == 1) { + if (flags & UNESCAPE_RELAX) { + /* A trailing backslash, copy verbatim */ + *(t++) = *f; + continue; + } + + return -EINVAL; + } + + r = cunescape_one(f + 1, remaining - 1, &u, &eight_bit, flags & UNESCAPE_ACCEPT_NUL); + if (r < 0) { + if (flags & UNESCAPE_RELAX) { + /* Invalid escape code, let's take it literal then */ + *(t++) = '\\'; + continue; + } + + return r; + } + + f += r; + if (eight_bit) + /* One byte? Set directly as specified */ + *(t++) = u; + else + /* Otherwise encode as multi-byte UTF-8 */ + t += utf8_encode_unichar(t, u); + } + + *t = 0; + + assert(t >= ans); /* Let static analyzers know that the answer is non-negative. */ + *ret = TAKE_PTR(ans); + return t - *ret; +} + +char* xescape_full(const char *s, const char *bad, size_t console_width, XEscapeFlags flags) { + char *ans, *t, *prev, *prev2; + const char *f; + + /* Escapes all chars in bad, in addition to \ and all special chars, in \xFF style escaping. May be + * reversed with cunescape(). If XESCAPE_8_BIT is specified, characters >= 127 are let through + * unchanged. This corresponds to non-ASCII printable characters in pre-unicode encodings. + * + * If console_width is reached, or XESCAPE_FORCE_ELLIPSIS is set, output is truncated and "..." is + * appended. */ + + if (console_width == 0) + return strdup(""); + + ans = new(char, MIN(strlen(s), console_width) * 4 + 1); + if (!ans) + return NULL; + + memset(ans, '_', MIN(strlen(s), console_width) * 4); + ans[MIN(strlen(s), console_width) * 4] = 0; + + bool force_ellipsis = FLAGS_SET(flags, XESCAPE_FORCE_ELLIPSIS); + + for (f = s, t = prev = prev2 = ans; ; f++) { + char *tmp_t = t; + + if (!*f) { + if (force_ellipsis) + break; + + *t = 0; + return ans; + } + + if ((unsigned char) *f < ' ' || + (!FLAGS_SET(flags, XESCAPE_8_BIT) && (unsigned char) *f >= 127) || + *f == '\\' || strchr(bad, *f)) { + if ((size_t) (t - ans) + 4 + 3 * force_ellipsis > console_width) + break; + + *(t++) = '\\'; + *(t++) = 'x'; + *(t++) = hexchar(*f >> 4); + *(t++) = hexchar(*f); + } else { + if ((size_t) (t - ans) + 1 + 3 * force_ellipsis > console_width) + break; + + *(t++) = *f; + } + + /* We might need to go back two cycles to fit three dots, so remember two positions */ + prev2 = prev; + prev = tmp_t; + } + + /* We can just write where we want, since chars are one-byte */ + size_t c = MIN(console_width, 3u); /* If the console is too narrow, write fewer dots */ + size_t off; + if (console_width - c >= (size_t) (t - ans)) + off = (size_t) (t - ans); + else if (console_width - c >= (size_t) (prev - ans)) + off = (size_t) (prev - ans); + else if (console_width - c >= (size_t) (prev2 - ans)) + off = (size_t) (prev2 - ans); + else + off = console_width - c; + assert(off <= (size_t) (t - ans)); + + memcpy(ans + off, "...", c); + ans[off + c] = '\0'; + return ans; +} + +char* escape_non_printable_full(const char *str, size_t console_width, XEscapeFlags flags) { + if (FLAGS_SET(flags, XESCAPE_8_BIT)) + return xescape_full(str, "", console_width, flags); + else + return utf8_escape_non_printable_full(str, + console_width, + FLAGS_SET(flags, XESCAPE_FORCE_ELLIPSIS)); +} + +char* octescape(const char *s, size_t len) { + char *buf, *t; + + /* Escapes all chars in bad, in addition to \ and " chars, in \nnn style escaping. */ + + assert(s || len == 0); + + t = buf = new(char, len * 4 + 1); + if (!buf) + return NULL; + + for (size_t i = 0; i < len; i++) { + uint8_t u = (uint8_t) s[i]; + + if (u < ' ' || u >= 127 || IN_SET(u, '\\', '"')) { + *(t++) = '\\'; + *(t++) = '0' + (u >> 6); + *(t++) = '0' + ((u >> 3) & 7); + *(t++) = '0' + (u & 7); + } else + *(t++) = u; + } + + *t = 0; + return buf; +} + +static char* strcpy_backslash_escaped(char *t, const char *s, const char *bad) { + assert(bad); + assert(t); + assert(s); + + while (*s) { + int l = utf8_encoded_valid_unichar(s, SIZE_MAX); + + if (char_is_cc(*s) || l < 0) + t += cescape_char(*(s++), t); + else if (l == 1) { + if (*s == '\\' || strchr(bad, *s)) + *(t++) = '\\'; + *(t++) = *(s++); + } else { + t = mempcpy(t, s, l); + s += l; + } + } + + return t; +} + +char* shell_escape(const char *s, const char *bad) { + char *buf, *t; + + buf = new(char, strlen(s)*4+1); + if (!buf) + return NULL; + + t = strcpy_backslash_escaped(buf, s, bad); + *t = 0; + + return buf; +} + +char* shell_maybe_quote(const char *s, ShellEscapeFlags flags) { + const char *p; + char *buf, *t; + + assert(s); + + /* Encloses a string in quotes if necessary to make it OK as a shell string. */ + + if (FLAGS_SET(flags, SHELL_ESCAPE_EMPTY) && isempty(s)) + return strdup("\"\""); /* We don't use $'' here in the POSIX mode. "" is fine too. */ + + for (p = s; *p; ) { + int l = utf8_encoded_valid_unichar(p, SIZE_MAX); + + if (char_is_cc(*p) || l < 0 || + strchr(WHITESPACE SHELL_NEED_QUOTES, *p)) + break; + + p += l; + } + + if (!*p) + return strdup(s); + + buf = new(char, FLAGS_SET(flags, SHELL_ESCAPE_POSIX) + 1 + strlen(s)*4 + 1 + 1); + if (!buf) + return NULL; + + t = buf; + if (FLAGS_SET(flags, SHELL_ESCAPE_POSIX)) { + *(t++) = '$'; + *(t++) = '\''; + } else + *(t++) = '"'; + + t = mempcpy(t, s, p - s); + + t = strcpy_backslash_escaped(t, p, + FLAGS_SET(flags, SHELL_ESCAPE_POSIX) ? SHELL_NEED_ESCAPE_POSIX : SHELL_NEED_ESCAPE); + + if (FLAGS_SET(flags, SHELL_ESCAPE_POSIX)) + *(t++) = '\''; + else + *(t++) = '"'; + *t = 0; + + return str_realloc(buf); +} + +char* quote_command_line(char **argv, ShellEscapeFlags flags) { + _cleanup_free_ char *result = NULL; + + assert(argv); + + STRV_FOREACH(a, argv) { + _cleanup_free_ char *t = NULL; + + t = shell_maybe_quote(*a, flags); + if (!t) + return NULL; + + if (!strextend_with_separator(&result, " ", t)) + return NULL; + } + + return str_realloc(TAKE_PTR(result)); +} |