| /* SPDX-License-Identifier: LGPL-2.1+ */ |
| |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "alloc-util.h" |
| #include "escape.h" |
| #include "hexdecoct.h" |
| #include "macro.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) { |
| int r = 1; |
| |
| assert(p); |
| 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_t) -1 && 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_t) -1 && 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) |
| 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_t) -1 && 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) |
| 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_t) -1 && 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) |
| 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_t) -1 && 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) |
| 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; |
| } |
| |
| int cunescape_length_with_prefix(const char *s, size_t length, const char *prefix, UnescapeFlags flags, char **ret) { |
| char *r, *t; |
| const char *f; |
| size_t pl; |
| |
| assert(s); |
| assert(ret); |
| |
| /* Undoes C style string escaping, and optionally prefixes it. */ |
| |
| pl = strlen_ptr(prefix); |
| |
| r = new(char, pl+length+1); |
| if (!r) |
| return -ENOMEM; |
| |
| if (prefix) |
| memcpy(r, prefix, pl); |
| |
| for (f = s, t = r + pl; f < s + length; f++) { |
| size_t remaining; |
| bool eight_bit = false; |
| char32_t u; |
| int k; |
| |
| 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; |
| } |
| |
| free(r); |
| return -EINVAL; |
| } |
| |
| k = cunescape_one(f + 1, remaining - 1, &u, &eight_bit); |
| if (k < 0) { |
| if (flags & UNESCAPE_RELAX) { |
| /* Invalid escape code, let's take it literal then */ |
| *(t++) = '\\'; |
| continue; |
| } |
| |
| free(r); |
| return k; |
| } |
| |
| f += k; |
| 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; |
| |
| *ret = r; |
| return t - r; |
| } |
| |
| int cunescape_length(const char *s, size_t length, UnescapeFlags flags, char **ret) { |
| return cunescape_length_with_prefix(s, length, NULL, flags, ret); |
| } |
| |
| int cunescape(const char *s, UnescapeFlags flags, char **ret) { |
| return cunescape_length(s, strlen(s), flags, ret); |
| } |
| |
| char *xescape(const char *s, const char *bad) { |
| char *r, *t; |
| const char *f; |
| |
| /* Escapes all chars in bad, in addition to \ and all special |
| * chars, in \xFF style escaping. May be reversed with |
| * cunescape(). */ |
| |
| r = new(char, strlen(s) * 4 + 1); |
| if (!r) |
| return NULL; |
| |
| for (f = s, t = r; *f; f++) { |
| |
| if ((*f < ' ') || (*f >= 127) || |
| (*f == '\\') || strchr(bad, *f)) { |
| *(t++) = '\\'; |
| *(t++) = 'x'; |
| *(t++) = hexchar(*f >> 4); |
| *(t++) = hexchar(*f); |
| } else |
| *(t++) = *f; |
| } |
| |
| *t = 0; |
| |
| return r; |
| } |
| |
| char *octescape(const char *s, size_t len) { |
| char *r, *t; |
| const char *f; |
| |
| /* Escapes all chars in bad, in addition to \ and " chars, |
| * in \nnn style escaping. */ |
| |
| r = new(char, len * 4 + 1); |
| if (!r) |
| return NULL; |
| |
| for (f = s, t = r; f < s + len; f++) { |
| |
| if (*f < ' ' || *f >= 127 || IN_SET(*f, '\\', '"')) { |
| *(t++) = '\\'; |
| *(t++) = '0' + (*f >> 6); |
| *(t++) = '0' + ((*f >> 3) & 8); |
| *(t++) = '0' + (*f & 8); |
| } else |
| *(t++) = *f; |
| } |
| |
| *t = 0; |
| |
| return r; |
| |
| } |
| |
| static char *strcpy_backslash_escaped(char *t, const char *s, const char *bad, bool escape_tab_nl) { |
| assert(bad); |
| |
| for (; *s; s++) { |
| if (escape_tab_nl && IN_SET(*s, '\n', '\t')) { |
| *(t++) = '\\'; |
| *(t++) = *s == '\n' ? 'n' : 't'; |
| continue; |
| } |
| |
| if (*s == '\\' || strchr(bad, *s)) |
| *(t++) = '\\'; |
| |
| *(t++) = *s; |
| } |
| |
| return t; |
| } |
| |
| char *shell_escape(const char *s, const char *bad) { |
| char *r, *t; |
| |
| r = new(char, strlen(s)*2+1); |
| if (!r) |
| return NULL; |
| |
| t = strcpy_backslash_escaped(r, s, bad, false); |
| *t = 0; |
| |
| return r; |
| } |
| |
| char* shell_maybe_quote(const char *s, EscapeStyle style) { |
| const char *p; |
| char *r, *t; |
| |
| assert(s); |
| |
| /* Encloses a string in quotes if necessary to make it OK as a shell |
| * string. Note that we treat benign UTF-8 characters as needing |
| * escaping too, but that should be OK. */ |
| |
| for (p = s; *p; p++) |
| if (*p <= ' ' || |
| *p >= 127 || |
| strchr(SHELL_NEED_QUOTES, *p)) |
| break; |
| |
| if (!*p) |
| return strdup(s); |
| |
| r = new(char, (style == ESCAPE_POSIX) + 1 + strlen(s)*2 + 1 + 1); |
| if (!r) |
| return NULL; |
| |
| t = r; |
| if (style == ESCAPE_BACKSLASH) |
| *(t++) = '"'; |
| else if (style == ESCAPE_POSIX) { |
| *(t++) = '$'; |
| *(t++) = '\''; |
| } else |
| assert_not_reached("Bad EscapeStyle"); |
| |
| t = mempcpy(t, s, p - s); |
| |
| if (style == ESCAPE_BACKSLASH) |
| t = strcpy_backslash_escaped(t, p, SHELL_NEED_ESCAPE, false); |
| else |
| t = strcpy_backslash_escaped(t, p, SHELL_NEED_ESCAPE_POSIX, true); |
| |
| if (style == ESCAPE_BACKSLASH) |
| *(t++) = '"'; |
| else |
| *(t++) = '\''; |
| *t = 0; |
| |
| return r; |
| } |