text: /*	$Id: read.c,v 1.213 2019/06/03 19:58:02 schwarze Exp $ */
  /*
   * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
   * Copyright (c) 2010-2019 Ingo Schwarze <schwarze@openbsd.org>
   * Copyright (c) 2010, 2012 Joerg Sonnenberger <joerg@netbsd.org>
   *
   * Permission to use, copy, modify, and distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   */
  #include "config.h"
  
  #include <sys/types.h>
  #include <sys/mman.h>
  #include <sys/stat.h>
  
  #include <assert.h>
  #include <ctype.h>
  #include <errno.h>
  #include <fcntl.h>
  #include <stdarg.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  #include <zlib.h>
  
  #include "mandoc_aux.h"
  #include "mandoc.h"
  #include "roff.h"
  #include "mdoc.h"
  #include "man.h"
  #include "mandoc_parse.h"
  #include "libmandoc.h"
  #include "roff_int.h"
  
  #define	REPARSE_LIMIT	1000
  
  struct	mparse {
  	struct roff	 *roff; /* roff parser (!NULL) */
  	struct roff_man	 *man; /* man parser */
  	struct buf	 *primary; /* buffer currently being parsed */
  	struct buf	 *secondary; /* copy of top level input */
  	struct buf	 *loop; /* open .while request line */
  	const char	 *os_s; /* default operating system */
  	int		  options; /* parser options */
  	int		  gzip; /* current input file is gzipped */
  	int		  filenc; /* encoding of the current file */
  	int		  reparse_count; /* finite interp. stack */
  	int		  line; /* line number in the file */
  };
  
  static	void	  choose_parser(struct mparse *);
  static	void	  free_buf_list(struct buf *);
  static	void	  resize_buf(struct buf *, size_t);
  static	int	  mparse_buf_r(struct mparse *, struct buf, size_t, int);
  static	int	  read_whole_file(struct mparse *, int, struct buf *, int *);
  static	void	  mparse_end(struct mparse *);
  
  
  static void
  resize_buf(struct buf *buf, size_t initial)
  {
  
  	buf->sz = buf->sz > initial/2 ? 2 * buf->sz : initial;
  	buf->buf = mandoc_realloc(buf->buf, buf->sz);
  }
  
  static void
  free_buf_list(struct buf *buf)
  {
  	struct buf *tmp;
  
  	while (buf != NULL) {
  		tmp = buf;
  		buf = tmp->next;
  		free(tmp->buf);
  		free(tmp);
  	}
  }
  
  static void
  choose_parser(struct mparse *curp)
  {
  	char		*cp, *ep;
  	int		 format;
  
  	/*
  	 * If neither command line arguments -mdoc or -man select
  	 * a parser nor the roff parser found a .Dd or .TH macro
  	 * yet, look ahead in the main input buffer.
  	 */
  
  	if ((format = roff_getformat(curp->roff)) == 0) {
  		cp = curp->primary->buf;
  		ep = cp + curp->primary->sz;
  		while (cp < ep) {
  			if (*cp == '.' || *cp == '\'') {
  				cp++;
  				if (cp[0] == 'D' && cp[1] == 'd') {
  					format = MPARSE_MDOC;
  					break;
  				}
  				if (cp[0] == 'T' && cp[1] == 'H') {
  					format = MPARSE_MAN;
  					break;
  				}
  			}
  			cp = memchr(cp, '\n', ep - cp);
  			if (cp == NULL)
  				break;
  			cp++;
  		}
  	}
  
  	if (format == MPARSE_MDOC) {
  		curp->man->meta.macroset = MACROSET_MDOC;
  		if (curp->man->mdocmac == NULL)
  			curp->man->mdocmac = roffhash_alloc(MDOC_Dd, MDOC_MAX);
  	} else {
  		curp->man->meta.macroset = MACROSET_MAN;
  		if (curp->man->manmac == NULL)
  			curp->man->manmac = roffhash_alloc(MAN_TH, MAN_MAX);
  	}
  	curp->man->meta.first->tok = TOKEN_NONE;
  }
  
  /*
   * Main parse routine for a buffer.
   * It assumes encoding and line numbering are already set up.
   * It can recurse directly (for invocations of user-defined
   * macros, inline equations, and input line traps)
   * and indirectly (for .so file inclusion).
   */
  static int
  mparse_buf_r(struct mparse *curp, struct buf blk, size_t i, int start)
  {
  	struct buf	 ln;
  	struct buf	*firstln, *lastln, *thisln, *loop;
  	char		*cp;
  	size_t		 pos; /* byte number in the ln buffer */
  	int		 line_result, result;
  	int		 of;
  	int		 lnn; /* line number in the real file */
  	int		 fd;
  	int		 inloop; /* Saw .while on this level. */
  	unsigned char	 c;
  
  	ln.sz = 256;
  	ln.buf = mandoc_malloc(ln.sz);
  	ln.next = NULL;
  	firstln = lastln = loop = NULL;
  	lnn = curp->line;
  	pos = 0;
  	inloop = 0;
  	result = ROFF_CONT;
  
  	while (i < blk.sz && (blk.buf[i] != '\0' || pos != 0)) {
  		if (start) {
  			curp->line = lnn;
  			curp->reparse_count = 0;
  
  			if (lnn < 3 &&
  			    curp->filenc & MPARSE_UTF8 &&
  			    curp->filenc & MPARSE_LATIN1)
  				curp->filenc = preconv_cue(&blk, i);
  		}
  
  		while (i < blk.sz && (start || blk.buf[i] != '\0')) {
  
  			/*
  			 * When finding an unescaped newline character,
  			 * leave the character loop to process the line.
  			 * Skip a preceding carriage return, if any.
  			 */
  
  			if ('\r' == blk.buf[i] && i + 1 < blk.sz &&
  			    '\n' == blk.buf[i + 1])
  				++i;
  			if ('\n' == blk.buf[i]) {
  				++i;
  				++lnn;
  				break;
  			}
  
  			/*
  			 * Make sure we have space for the worst
  			 * case of 12 bytes: "\\[u10ffff]\n\0"
  			 */
  
  			if (pos + 12 > ln.sz)
  				resize_buf(&ln, 256);
  
  			/*
  			 * Encode 8-bit input.
  			 */
  
  			c = blk.buf[i];
  			if (c & 0x80) {
  				if ( ! (curp->filenc && preconv_encode(
  				    &blk, &i, &ln, &pos, &curp->filenc))) {
  					mandoc_msg(MANDOCERR_CHAR_BAD,
  					    curp->line, pos, "0x%x", c);
  					ln.buf[pos++] = '?';
  					i++;
  				}
  				continue;
  			}
  
  			/*
  			 * Exclude control characters.
  			 */
  
  			if (c == 0x7f || (c < 0x20 && c != 0x09)) {
  				mandoc_msg(c == 0x00 || c == 0x04 ||
  				    c > 0x0a ? MANDOCERR_CHAR_BAD :
  				    MANDOCERR_CHAR_UNSUPP,
  				    curp->line, pos, "0x%x", c);
  				i++;
  				if (c != '\r')
  					ln.buf[pos++] = '?';
  				continue;
  			}
  
  			ln.buf[pos++] = blk.buf[i++];
  		}
  		ln.buf[pos] = '\0';
  
  		/*
  		 * Maintain a lookaside buffer of all lines.
  		 * parsed from this input source.
  		 */
  
  		thisln = mandoc_malloc(sizeof(*thisln));
  		thisln->buf = mandoc_strdup(ln.buf);
  		thisln->sz = strlen(ln.buf) + 1;
  		thisln->next = NULL;
  		if (firstln == NULL) {
  			firstln = lastln = thisln;
  			if (curp->secondary == NULL)
  				curp->secondary = firstln;
  		} else {
  			lastln->next = thisln;
  			lastln = thisln;
  		}
  
  		/* XXX Ugly hack to mark the end of the input. */
  
  		if (i == blk.sz || blk.buf[i] == '\0') {
  			ln.buf[pos++] = '\n';
  			ln.buf[pos] = '\0';
  		}
  
  		/*
  		 * A significant amount of complexity is contained by
  		 * the roff preprocessor.  It's line-oriented but can be
  		 * expressed on one line, so we need at times to
  		 * readjust our starting point and re-run it.  The roff
  		 * preprocessor can also readjust the buffers with new
  		 * data, so we pass them in wholesale.
  		 */
  
  		of = 0;
  rerun:
  		line_result = roff_parseln(curp->roff, curp->line, &ln, &of);
  
  		/* Process options. */
  
  		if (line_result & ROFF_APPEND)
  			assert(line_result == (ROFF_IGN | ROFF_APPEND));
  
  		if (line_result & ROFF_USERCALL)
  			assert((line_result & ROFF_MASK) == ROFF_REPARSE);
  
  		if (line_result & ROFF_USERRET) {
  			assert(line_result == (ROFF_IGN | ROFF_USERRET));
  			if (start == 0) {
  				/* Return from the current macro. */
  				result = ROFF_USERRET;
  				goto out;
  			}
  		}
  
  		switch (line_result & ROFF_LOOPMASK) {
  		case ROFF_IGN:
  			break;
  		case ROFF_WHILE:
  			if (curp->loop != NULL) {
  				if (loop == curp->loop)
  					break;
  				mandoc_msg(MANDOCERR_WHILE_NEST,
  				    curp->line, pos, NULL);
  			}
  			curp->loop = thisln;
  			loop = NULL;
  			inloop = 1;
  			break;
  		case ROFF_LOOPCONT:
  		case ROFF_LOOPEXIT:
  			if (curp->loop == NULL) {
  				mandoc_msg(MANDOCERR_WHILE_FAIL,
  				    curp->line, pos, NULL);
  				break;
  			}
  			if (inloop == 0) {
  				mandoc_msg(MANDOCERR_WHILE_INTO,
  				    curp->line, pos, NULL);
  				curp->loop = loop = NULL;
  				break;
  			}
  			if (line_result & ROFF_LOOPCONT)
  				loop = curp->loop;
  			else {
  				curp->loop = loop = NULL;
  				inloop = 0;
  			}
  			break;
  		default:
  			abort();
  		}
  
  		/* Process the main instruction from the roff parser. */
  
  		switch (line_result & ROFF_MASK) {
  		case ROFF_IGN:
  			break;
  		case ROFF_CONT:
  			if (curp->man->meta.macroset == MACROSET_NONE)
  				choose_parser(curp);
  			if ((curp->man->meta.macroset == MACROSET_MDOC ?
  			     mdoc_parseln(curp->man, curp->line, ln.buf, of) :
  			     man_parseln(curp->man, curp->line, ln.buf, of)
  			    ) == 2)
  				goto out;
  			break;
  		case ROFF_RERUN:
  			goto rerun;
  		case ROFF_REPARSE:
  			if (++curp->reparse_count > REPARSE_LIMIT) {
  				/* Abort and return to the top level. */
  				result = ROFF_IGN;
  				mandoc_msg(MANDOCERR_ROFFLOOP,
  				    curp->line, pos, NULL);
  				goto out;
  			}
  			result = mparse_buf_r(curp, ln, of, 0);
  			if (line_result & ROFF_USERCALL) {
  				roff_userret(curp->roff);
  				/* Continue normally. */
  				if (result & ROFF_USERRET)
  					result = ROFF_CONT;
  			}
  			if (start == 0 && result != ROFF_CONT)
  				goto out;
  			break;
  		case ROFF_SO:
  			if ( ! (curp->options & MPARSE_SO) &&
  			    (i >= blk.sz || blk.buf[i] == '\0')) {
  				curp->man->meta.sodest =
  				    mandoc_strdup(ln.buf + of);
  				goto out;
  			}
  			if ((fd = mparse_open(curp, ln.buf + of)) != -1) {
  				mparse_readfd(curp, fd, ln.buf + of);
  				close(fd);
  			} else {
  				mandoc_msg(MANDOCERR_SO_FAIL,
  				    curp->line, of, ".so %s: %s",
  				    ln.buf + of, strerror(errno));
  				ln.sz = mandoc_asprintf(&cp,
  				    ".sp\nSee the file %s.\n.sp",
  				    ln.buf + of);
  				free(ln.buf);
  				ln.buf = cp;
  				of = 0;
  				mparse_buf_r(curp, ln, of, 0);
  			}
  			break;
  		default:
  			abort();
  		}
  
  		/* Start the next input line. */
  
  		if (loop != NULL &&
  		    (line_result & ROFF_LOOPMASK) == ROFF_IGN)
  			loop = loop->next;
  
  		if (loop != NULL) {
  			if ((line_result & ROFF_APPEND) == 0)
  				*ln.buf = '\0';
  			if (ln.sz < loop->sz)
  				resize_buf(&ln, loop->sz);
  			(void)strlcat(ln.buf, loop->buf, ln.sz);
  			of = 0;
  			goto rerun;
  		}
  
  		pos = (line_result & ROFF_APPEND) ? strlen(ln.buf) : 0;
  	}
  out:
  	if (inloop) {
  		if (result != ROFF_USERRET)
  			mandoc_msg(MANDOCERR_WHILE_OUTOF,
  			    curp->line, pos, NULL);
  		curp->loop = NULL;
  	}
  	free(ln.buf);
  	if (firstln != curp->secondary)
  		free_buf_list(firstln);
  	return result;
  }
  
  static int
  read_whole_file(struct mparse *curp, int fd, struct buf *fb, int *with_mmap)
  {
  	struct stat	 st;
  	gzFile		 gz;
  	size_t		 off;
  	ssize_t		 ssz;
  	int		 gzerrnum, retval;
  
  	if (fstat(fd, &st) == -1) {
  		mandoc_msg(MANDOCERR_FILE, 0, 0,
  		    "fstat: %s", strerror(errno));
  		return 0;
  	}
  
  	/*
  	 * If we're a regular file, try just reading in the whole entry
  	 * via mmap().  This is faster than reading it into blocks, and
  	 * since each file is only a few bytes to begin with, I'm not
  	 * concerned that this is going to tank any machines.
  	 */
  
  	if (curp->gzip == 0 && S_ISREG(st.st_mode)) {
  		if (st.st_size > 0x7fffffff) {
  			mandoc_msg(MANDOCERR_TOOLARGE, 0, 0, NULL);
  			return 0;
  		}
  		*with_mmap = 1;
  		fb->sz = (size_t)st.st_size;
  		fb->buf = mmap(NULL, fb->sz, PROT_READ, MAP_SHARED, fd, 0);
  		if (fb->buf != MAP_FAILED)
  			return 1;
  	}
  
  	if (curp->gzip) {
  		/*
  		 * Duplicating the file descriptor is required
  		 * because we will have to call gzclose(3)
  		 * to free memory used internally by zlib,
  		 * but that will also close the file descriptor,
  		 * which this function must not do.
  		 */
  		if ((fd = dup(fd)) == -1) {
  			mandoc_msg(MANDOCERR_FILE, 0, 0,
  			    "dup: %s", strerror(errno));
  			return 0;
  		}
  		if ((gz = gzdopen(fd, "rb")) == NULL) {
  			mandoc_msg(MANDOCERR_FILE, 0, 0,
  			    "gzdopen: %s", strerror(errno));
  			close(fd);
  			return 0;
  		}
  	} else
  		gz = NULL;
  
  	/*
  	 * If this isn't a regular file (like, say, stdin), then we must
  	 * go the old way and just read things in bit by bit.
  	 */
  
  	*with_mmap = 0;
  	off = 0;
  	retval = 0;
  	fb->sz = 0;
  	fb->buf = NULL;
  	for (;;) {
  		if (off == fb->sz) {
  			if (fb->sz == (1U << 31)) {
  				mandoc_msg(MANDOCERR_TOOLARGE, 0, 0, NULL);
  				break;
  			}
  			resize_buf(fb, 65536);
  		}
  		ssz = curp->gzip ?
  		    gzread(gz, fb->buf + (int)off, fb->sz - off) :
  		    read(fd, fb->buf + (int)off, fb->sz - off);
  		if (ssz == 0) {
  			fb->sz = off;
  			retval = 1;
  			break;
  		}
  		if (ssz == -1) {
  			if (curp->gzip)
  				(void)gzerror(gz, &gzerrnum);
  			mandoc_msg(MANDOCERR_FILE, 0, 0, "read: %s",
  			    curp->gzip && gzerrnum != Z_ERRNO ?
  			    zError(gzerrnum) : strerror(errno));
  			break;
  		}
  		off += (size_t)ssz;
  	}
  
  	if (curp->gzip && (gzerrnum = gzclose(gz)) != Z_OK)
  		mandoc_msg(MANDOCERR_FILE, 0, 0, "gzclose: %s",
  		    gzerrnum == Z_ERRNO ? strerror(errno) :
  		    zError(gzerrnum));
  	if (retval == 0) {
  		free(fb->buf);
  		fb->buf = NULL;
  	}
  	return retval;
  }
  
  static void
  mparse_end(struct mparse *curp)
  {
  	if (curp->man->meta.macroset == MACROSET_NONE)
  		curp->man->meta.macroset = MACROSET_MAN;
  	if (curp->man->meta.macroset == MACROSET_MDOC)
  		mdoc_endparse(curp->man);
  	else
  		man_endparse(curp->man);
  	roff_endparse(curp->roff);
  }
  
  /*
   * Read the whole file into memory and call the parsers.
   * Called recursively when an .so request is encountered.
   */
  void
  mparse_readfd(struct mparse *curp, int fd, const char *filename)
  {
  	static int	 recursion_depth;
  
  	struct buf	 blk;
  	struct buf	*save_primary;
  	const char	*save_filename;
  	size_t		 offset;
  	int		 save_filenc, save_lineno;
  	int		 with_mmap;
  
  	if (recursion_depth > 64) {
  		mandoc_msg(MANDOCERR_ROFFLOOP, curp->line, 0, NULL);
  		return;
  	}
  	if (read_whole_file(curp, fd, &blk, &with_mmap) == 0)
  		return;
  
  	/*
  	 * Save some properties of the parent file.
  	 */
  
  	save_primary = curp->primary;
  	save_filenc = curp->filenc;
  	save_lineno = curp->line;
  	save_filename = mandoc_msg_getinfilename();
  
  	curp->primary = &blk;
  	curp->filenc = curp->options & (MPARSE_UTF8 | MPARSE_LATIN1);
  	curp->line = 1;
  	mandoc_msg_setinfilename(filename);
  
  	/* Skip an UTF-8 byte order mark. */
  	if (curp->filenc & MPARSE_UTF8 && blk.sz > 2 &&
  	    (unsigned char)blk.buf[0] == 0xef &&
  	    (unsigned char)blk.buf[1] == 0xbb &&
  	    (unsigned char)blk.buf[2] == 0xbf) {
  		offset = 3;
  		curp->filenc &= ~MPARSE_LATIN1;
  	} else
  		offset = 0;
  
  	recursion_depth++;
  	mparse_buf_r(curp, blk, offset, 1);
  	if (--recursion_depth == 0)
  		mparse_end(curp);
  
  	/*
  	 * Clean up and restore saved parent properties.
  	 */
  
  	if (with_mmap)
  		munmap(blk.buf, blk.sz);
  	else
  		free(blk.buf);
  
  	curp->primary = save_primary;
  	curp->filenc = save_filenc;
  	curp->line = save_lineno;
  	if (save_filename != NULL)
  		mandoc_msg_setinfilename(save_filename);
  }
  
  int
  mparse_open(struct mparse *curp, const char *file)
  {
  	char		 *cp;
  	int		  fd, save_errno;
  
  	cp = strrchr(file, '.');
  	curp->gzip = (cp != NULL && ! strcmp(cp + 1, "gz"));
  
  	/* First try to use the filename as it is. */
  
  	if ((fd = open(file, O_RDONLY)) != -1)
  		return fd;
  
  	/*
  	 * If that doesn't work and the filename doesn't
  	 * already  end in .gz, try appending .gz.
  	 */
  
  	if ( ! curp->gzip) {
  		save_errno = errno;
  		mandoc_asprintf(&cp, "%s.gz", file);
  		fd = open(cp, O_RDONLY);
  		free(cp);
  		errno = save_errno;
  		if (fd != -1) {
  			curp->gzip = 1;
  			return fd;
  		}
  	}
  
  	/* Neither worked, give up. */
  
  	return -1;
  }
  
  struct mparse *
  mparse_alloc(int options, enum mandoc_os os_e, const char *os_s)
  {
  	struct mparse	*curp;
  
  	curp = mandoc_calloc(1, sizeof(struct mparse));
  
  	curp->options = options;
  	curp->os_s = os_s;
  
  	curp->roff = roff_alloc(options);
  	curp->man = roff_man_alloc(curp->roff, curp->os_s,
  		curp->options & MPARSE_QUICK ? 1 : 0);
  	if (curp->options & MPARSE_MDOC) {
  		curp->man->meta.macroset = MACROSET_MDOC;
  		if (curp->man->mdocmac == NULL)
  			curp->man->mdocmac = roffhash_alloc(MDOC_Dd, MDOC_MAX);
  	} else if (curp->options & MPARSE_MAN) {
  		curp->man->meta.macroset = MACROSET_MAN;
  		if (curp->man->manmac == NULL)
  			curp->man->manmac = roffhash_alloc(MAN_TH, MAN_MAX);
  	}
  	curp->man->meta.first->tok = TOKEN_NONE;
  	curp->man->meta.os_e = os_e;
  	return curp;
  }
  
  void
  mparse_reset(struct mparse *curp)
  {
  	roff_reset(curp->roff);
  	roff_man_reset(curp->man);
  	free_buf_list(curp->secondary);
  	curp->secondary = NULL;
  	curp->gzip = 0;
  }
  
  void
  mparse_free(struct mparse *curp)
  {
  	roffhash_free(curp->man->mdocmac);
  	roffhash_free(curp->man->manmac);
  	roff_man_free(curp->man);
  	roff_free(curp->roff);
  	free_buf_list(curp->secondary);
  	free(curp);
  }
  
  struct roff_meta *
  mparse_result(struct mparse *curp)
  {
  	roff_state_reset(curp->man);
  	if (curp->options & MPARSE_VALIDATE) {
  		if (curp->man->meta.macroset == MACROSET_MDOC)
  			mdoc_validate(curp->man);
  		else
  			man_validate(curp->man);
  	}
  	return &curp->man->meta;
  }
  
  void
  mparse_copy(const struct mparse *p)
  {
  	struct buf	*buf;
  
  	for (buf = p->secondary; buf != NULL; buf = buf->next)
  		puts(buf->buf);
  }
  