/* $OpenBSD: vis.c,v 1.26 2022/05/04 18:57:50 deraadt Exp $ */ /*- * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include "../config.h" #include #include #include #include #include #include #include static int isoctal(int c) { u_char uc = c; return uc >= '0' && uc <= '7'; } static int isvisible(int c, int flag) { int vis_sp = flag & VIS_SP; int vis_tab = flag & VIS_TAB; int vis_nl = flag & VIS_NL; int vis_safe = flag & VIS_SAFE; int vis_glob = flag & VIS_GLOB; int vis_all = flag & VIS_ALL; u_char uc = c; if (c == '\\' || !vis_all) { if ((u_int)c <= UCHAR_MAX && isascii(uc) && ((c != '*' && c != '?' && c != '[' && c != '#') || !vis_glob) && isgraph(uc)) return 1; if (!vis_sp && c == ' ') return 1; if (!vis_tab && c == '\t') return 1; if (!vis_nl && c == '\n') return 1; if (vis_safe && (c == '\b' || c == '\007' || c == '\r' || isgraph(uc))) return 1; } return 0; } /* * vis - visually encode characters */ char * vis(char *dst, int c, int flag, int nextc) { int vis_dq = flag & VIS_DQ; int vis_noslash = flag & VIS_NOSLASH; int vis_cstyle = flag & VIS_CSTYLE; int vis_octal = flag & VIS_OCTAL; int vis_glob = flag & VIS_GLOB; if (isvisible(c, flag)) { if ((c == '"' && vis_dq) || (c == '\\' && !vis_noslash)) *dst++ = '\\'; *dst++ = c; *dst = '\0'; return (dst); } if (vis_cstyle) { switch (c) { case '\n': *dst++ = '\\'; *dst++ = 'n'; goto done; case '\r': *dst++ = '\\'; *dst++ = 'r'; goto done; case '\b': *dst++ = '\\'; *dst++ = 'b'; goto done; case '\a': *dst++ = '\\'; *dst++ = 'a'; goto done; case '\v': *dst++ = '\\'; *dst++ = 'v'; goto done; case '\t': *dst++ = '\\'; *dst++ = 't'; goto done; case '\f': *dst++ = '\\'; *dst++ = 'f'; goto done; case ' ': *dst++ = '\\'; *dst++ = 's'; goto done; case '\0': *dst++ = '\\'; *dst++ = '0'; if (isoctal(nextc)) { *dst++ = '0'; *dst++ = '0'; } goto done; } } if (((c & 0177) == ' ') || vis_octal || (vis_glob && (c == '*' || c == '?' || c == '[' || c == '#'))) { *dst++ = '\\'; *dst++ = ((u_char)c >> 6 & 07) + '0'; *dst++ = ((u_char)c >> 3 & 07) + '0'; *dst++ = ((u_char)c & 07) + '0'; goto done; } if (!vis_noslash) *dst++ = '\\'; if (c & 0200) { c &= 0177; *dst++ = 'M'; } if (iscntrl((u_char)c)) { *dst++ = '^'; if (c == 0177) *dst++ = '?'; else *dst++ = c + '@'; } else { *dst++ = '-'; *dst++ = c; } done: *dst = '\0'; return (dst); } /* * strvis, strnvis, strvisx - visually encode characters from src into dst * * Dst must be 4 times the size of src to account for possible * expansion. The length of dst, not including the trailing NULL, * is returned. * * Strnvis will write no more than siz-1 bytes (and will NULL terminate). * The number of bytes needed to fully encode the string is returned. * * Strvisx encodes exactly len bytes from src into dst. * This is useful for encoding a block of data. */ int strvis(char *dst, const char *src, int flag) { char c; char *start; for (start = dst; (c = *src);) dst = vis(dst, c, flag, *++src); *dst = '\0'; return (dst - start); } int strnvis(char *dst, const char *src, size_t siz, int flag) { int vis_dq = flag & VIS_DQ; int vis_noslash = flag & VIS_NOSLASH; char *start, *end; char tbuf[5]; int c, i; i = 0; for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) { if (isvisible(c, flag)) { if ((c == '"' && vis_dq) || (c == '\\' && !vis_noslash)) { /* need space for the extra '\\' */ if (dst + 1 >= end) { i = 2; break; } *dst++ = '\\'; } i = 1; *dst++ = c; src++; } else { i = vis(tbuf, c, flag, *++src) - tbuf; if (dst + i <= end) { memcpy(dst, tbuf, i); dst += i; } else { src--; break; } } } if (siz > 0) *dst = '\0'; if (dst + i > end) { /* adjust return value for truncation */ while ((c = *src)) dst += vis(tbuf, c, flag, *++src) - tbuf; } return (dst - start); } #if notneeded /* * This function triggers stupid gcc into thinking that buf is used * after realloc, breaking the build with -Werror. Since we don't * need this in gmid, comment it out so that gcc can be happy. */ int stravis(char **outp, const char *src, int flag) { char *buf; int len, serrno; buf = reallocarray(NULL, 4, strlen(src) + 1); if (buf == NULL) return -1; len = strvis(buf, src, flag); serrno = errno; *outp = realloc(buf, len + 1); if (*outp == NULL) { *outp = buf; errno = serrno; } return (len); } #endif int strvisx(char *dst, const char *src, size_t len, int flag) { char c; char *start; for (start = dst; len > 1; len--) { c = *src; dst = vis(dst, c, flag, *++src); } if (len) dst = vis(dst, *src, flag, '\0'); *dst = '\0'; return (dst - start); }