IABSD.fr/src/bin/chio/parse.y

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• Author : naddy
  Date : 2021-10-15 15:01:27
  Hash : 08f6ba19
  Message : Don't declare variables as "unsigned char *" that are passed to functions that take "char *" arguments. Where such chars are assigned to int or passed to ctype functions, explicitly cast them to unsigned char. For OpenBSD's clang, -Wpointer-sign has been disabled by default, but when the parse.y code was built elsewhere, the compiler would complain. With help from millert@ ok benno@ deraadt@

• bin/chio/parse.y

• /*	$OpenBSD: parse.y,v 1.24 2021/10/15 15:01:27 naddy Exp $ */
  
  /*
   * Copyright (c) 2006 Bob Beck <beck@openbsd.org>
   * Copyright (c) 2002-2006 Henning Brauer <henning@openbsd.org>
   * Copyright (c) 2001 Markus Friedl.  All rights reserved.
   * Copyright (c) 2001 Daniel Hartmeier.  All rights reserved.
   * Copyright (c) 2001 Theo de Raadt.  All rights reserved.
   *
   * 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 AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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 <sys/types.h>
  #include <sys/socket.h>
  #include <sys/queue.h>
  
  #include <ctype.h>
  #include <err.h>
  #include <libgen.h>
  #include <limits.h>
  #include <paths.h>
  #include <stdarg.h>
  #include <stdio.h>
  #include <string.h>
  
  TAILQ_HEAD(files, file)		 files = TAILQ_HEAD_INITIALIZER(files);
  static struct file {
  	TAILQ_ENTRY(file)	 entry;
  	FILE			*stream;
  	char			*name;
  	int			 lineno;
  	int			 errors;
  } *file, *topfile;
  struct file	*pushfile(const char *);
  int		 popfile(void);
  int		 yyparse(void);
  int		 yylex(void);
  int		 yyerror(const char *, ...)
      __attribute__((__format__ (printf, 1, 2)))
      __attribute__((__nonnull__ (1)));
  int		 kw_cmp(const void *, const void *);
  int		 lookup(char *);
  int		 lgetc(int);
  int		 lungetc(int);
  int		 findeol(void);
  char		*parse_tapedev(const char *, const char *, int);
  struct changer	*new_changer(char *);
  
  struct changer {
  	TAILQ_ENTRY(changer)	  entry;
  	char			 *name;
  	char			**drives;
  	u_int			  drivecnt;
  };
  TAILQ_HEAD(changers, changer)	 changers;
  struct changer			*curchanger;
  
  typedef struct {
  	union {
  		int64_t			 number;
  		char			*string;
  	} v;
  	int lineno;
  } YYSTYPE;
  
  %}
  
  %token	CHANGER
  %token	DRIVE
  %token	ERROR
  %token	<v.string>		STRING
  %token	<v.number>		NUMBER
  %%
  
  grammar		: /* empty */
  		| grammar '\n'
  		| grammar main '\n'
  		| grammar error '\n'		{ file->errors++; }
  		;
  
  optnl		: '\n' optnl
  		|
  		;
  
  nl		: '\n' optnl
  		;
  
  main		: CHANGER STRING optnl '{' optnl {
  			curchanger = new_changer($2);
  		}
  		    changeropts_l '}' {
  			TAILQ_INSERT_TAIL(&changers, curchanger, entry);
  			curchanger = NULL;
  		}
  		;
  
  changeropts_l	: changeropts_l changeroptsl
  		| changeroptsl
  		;
  
  changeroptsl	: changeropts nl
  		| error nl
  		;
  
  changeropts	: DRIVE STRING	{
  			void *newp;
  
  			if ((newp = reallocarray(curchanger->drives,
  			    curchanger->drivecnt + 1,
  			    sizeof(curchanger->drives))) == NULL)
  				err(1, NULL);
  			curchanger->drives = newp;
  			if ((curchanger->drives[curchanger->drivecnt] =
  			    strdup($2)) == NULL)
  				err(1, NULL);
  			curchanger->drivecnt++;
  			free($2);
  		}
  		;
  
  %%
  
  struct keywords {
  	const char	*k_name;
  	int		 k_val;
  };
  
  int
  yyerror(const char *fmt, ...)
  {
  	va_list		 ap;
  	char		*msg;
  
  	file->errors++;
  	va_start(ap, fmt);
  	if (vasprintf(&msg, fmt, ap) == -1)
  		err(1, "yyerror vasprintf");
  	va_end(ap);
  	err(1, "%s:%d: %s", file->name, yylval.lineno, msg);
  	free(msg);
  	return (0);
  }
  
  int
  kw_cmp(const void *k, const void *e)
  {
  	return (strcmp(k, ((const struct keywords *)e)->k_name));
  }
  
  int
  lookup(char *s)
  {
  	/* this has to be sorted always */
  	static const struct keywords keywords[] = {
  		{ "changer",		CHANGER},
  		{ "drive",		DRIVE}
  	};
  	const struct keywords	*p;
  
  	p = bsearch(s, keywords, sizeof(keywords)/sizeof(keywords[0]),
  	    sizeof(keywords[0]), kw_cmp);
  
  	if (p)
  		return (p->k_val);
  	else
  		return (STRING);
  }
  
  #define MAXPUSHBACK	128
  
  char	*parsebuf;
  int	 parseindex;
  char	 pushback_buffer[MAXPUSHBACK];
  int	 pushback_index = 0;
  
  int
  lgetc(int quotec)
  {
  	int		c, next;
  
  	if (parsebuf) {
  		/* Read character from the parsebuffer instead of input. */
  		if (parseindex >= 0) {
  			c = (unsigned char)parsebuf[parseindex++];
  			if (c != '\0')
  				return (c);
  			parsebuf = NULL;
  		} else
  			parseindex++;
  	}
  
  	if (pushback_index)
  		return ((unsigned char)pushback_buffer[--pushback_index]);
  
  	if (quotec) {
  		if ((c = getc(file->stream)) == EOF) {
  			yyerror("reached end of file while parsing "
  			    "quoted string");
  			if (file == topfile || popfile() == EOF)
  				return (EOF);
  			return (quotec);
  		}
  		return (c);
  	}
  
  	while ((c = getc(file->stream)) == '\\') {
  		next = getc(file->stream);
  		if (next != '\n') {
  			c = next;
  			break;
  		}
  		yylval.lineno = file->lineno;
  		file->lineno++;
  	}
  
  	while (c == EOF) {
  		if (file == topfile || popfile() == EOF)
  			return (EOF);
  		c = getc(file->stream);
  	}
  	return (c);
  }
  
  int
  lungetc(int c)
  {
  	if (c == EOF)
  		return (EOF);
  	if (parsebuf) {
  		parseindex--;
  		if (parseindex >= 0)
  			return (c);
  	}
  	if (pushback_index + 1 >= MAXPUSHBACK)
  		return (EOF);
  	pushback_buffer[pushback_index++] = c;
  	return (c);
  }
  
  int
  findeol(void)
  {
  	int	c;
  
  	parsebuf = NULL;
  	pushback_index = 0;
  
  	/* skip to either EOF or the first real EOL */
  	while (1) {
  		c = lgetc(0);
  		if (c == '\n') {
  			file->lineno++;
  			break;
  		}
  		if (c == EOF)
  			break;
  	}
  	return (ERROR);
  }
  
  int
  yylex(void)
  {
  	char	 buf[8096];
  	char	*p;
  	int	 quotec, next, c;
  	int	 token;
  
  	p = buf;
  	while ((c = lgetc(0)) == ' ' || c == '\t')
  		; /* nothing */
  
  	yylval.lineno = file->lineno;
  	if (c == '#')
  		while ((c = lgetc(0)) != '\n' && c != EOF)
  			; /* nothing */
  
  	switch (c) {
  	case '\'':
  	case '"':
  		quotec = c;
  		while (1) {
  			if ((c = lgetc(quotec)) == EOF)
  				return (0);
  			if (c == '\n') {
  				file->lineno++;
  				continue;
  			} else if (c == '\\') {
  				if ((next = lgetc(quotec)) == EOF)
  					return (0);
  				if (next == quotec || c == ' ' || c == '\t')
  					c = next;
  				else if (next == '\n')
  					continue;
  				else
  					lungetc(next);
  			} else if (c == quotec) {
  				*p = '\0';
  				break;
  			} else if (c == '\0') {
  				yyerror("syntax error");
  				return (findeol());
  			}
  			if (p + 1 >= buf + sizeof(buf) - 1) {
  				yyerror("string too long");
  				return (findeol());
  			}
  			*p++ = c;
  		}
  		yylval.v.string = strdup(buf);
  		if (yylval.v.string == NULL)
  			err(1, "%s", __func__);
  		return (STRING);
  	}
  
  #define allowed_to_end_number(x) \
  	(isspace(x) || x == ')' || x ==',' || x == '/' || x == '}' || x == '=')
  
  	if (c == '-' || isdigit(c)) {
  		do {
  			*p++ = c;
  			if ((size_t)(p-buf) >= sizeof(buf)) {
  				yyerror("string too long");
  				return (findeol());
  			}
  		} while ((c = lgetc(0)) != EOF && isdigit(c));
  		lungetc(c);
  		if (p == buf + 1 && buf[0] == '-')
  			goto nodigits;
  		if (c == EOF || allowed_to_end_number(c)) {
  			const char *errstr = NULL;
  
  			*p = '\0';
  			yylval.v.number = strtonum(buf, LLONG_MIN,
  			    LLONG_MAX, &errstr);
  			if (errstr) {
  				yyerror("\"%s\" invalid number: %s",
  				    buf, errstr);
  				return (findeol());
  			}
  			return (NUMBER);
  		} else {
  nodigits:
  			while (p > buf + 1)
  				lungetc((unsigned char)*--p);
  			c = (unsigned char)*--p;
  			if (c == '-')
  				return (c);
  		}
  	}
  
  #define allowed_in_string(x) \
  	(isalnum(x) || (ispunct(x) && x != '(' && x != ')' && \
  	x != '{' && x != '}' && x != '<' && x != '>' && \
  	x != '!' && x != '=' && x != '/' && x != '#' && \
  	x != ','))
  
  	if (isalnum(c) || c == ':' || c == '_' || c == '*') {
  		do {
  			*p++ = c;
  			if ((size_t)(p-buf) >= sizeof(buf)) {
  				yyerror("string too long");
  				return (findeol());
  			}
  		} while ((c = lgetc(0)) != EOF && (allowed_in_string(c)));
  		lungetc(c);
  		*p = '\0';
  		if ((token = lookup(buf)) == STRING)
  			if ((yylval.v.string = strdup(buf)) == NULL)
  				err(1, "%s", __func__);
  		return (token);
  	}
  	if (c == '\n') {
  		yylval.lineno = file->lineno;
  		file->lineno++;
  	}
  	if (c == EOF)
  		return (0);
  	return (c);
  }
  
  struct file *
  pushfile(const char *name)
  {
  	struct file	*nfile;
  
  	if ((nfile = calloc(1, sizeof(struct file))) == NULL)
  		return (NULL);
  	if ((nfile->name = strdup(name)) == NULL) {
  		free(nfile);
  		return (NULL);
  	}
  	if ((nfile->stream = fopen(nfile->name, "r")) == NULL) {
  		free(nfile->name);
  		free(nfile);
  		return (NULL);
  	}
  	nfile->lineno = 1;
  	TAILQ_INSERT_TAIL(&files, nfile, entry);
  	return (nfile);
  }
  
  int
  popfile(void)
  {
  	struct file	*prev;
  
  	if ((prev = TAILQ_PREV(file, files, entry)) != NULL)
  		prev->errors += file->errors;
  
  	TAILQ_REMOVE(&files, file, entry);
  	fclose(file->stream);
  	free(file->name);
  	free(file);
  	file = prev;
  	return (file ? 0 : EOF);
  }
  
  char *
  parse_tapedev(const char *filename, const char *changer, int drive)
  {
  	struct changer	*p;
  	char		*tapedev = NULL;
  	int		 errors = 0;
  
  	TAILQ_INIT(&changers);
  
  	if ((file = pushfile(filename)) == NULL) {
  		warnx("cannot open the main config file!");
  		goto guess;
  	}
  	topfile = file;
  
  	yyparse();
  	errors = file->errors;
  	popfile();
  
  	if (strncmp(changer, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
  		changer += sizeof(_PATH_DEV) - 1;
  	TAILQ_FOREACH(p, &changers, entry) {
  		if (strcmp(changer, p->name) == 0) {
  			if (drive >= 0 && drive < p->drivecnt) {
  				if (asprintf(&tapedev, _PATH_DEV "%s",
  				     p->drives[drive]) == -1)
  					errx(1, "malloc failed");
  			} else
  				tapedev = NULL;
  		}
  	}
  
  guess:
  	/* if no device found, do the default of /dev/rstX */
  	if (tapedev == NULL)
  		if (asprintf(&tapedev, "/dev/rst%d", drive) == -1)
  			errx(1, "malloc failed");
  	return (tapedev);
  }
  
  struct changer *
  new_changer(char *name)
  {
  	struct changer	*p;
  
  	if ((p = calloc(1, sizeof(*p))) == NULL)
  		err(1, NULL);
  
  	if ((p->name = strdup(name)) == NULL)
  		err(1, NULL);
  
  	return (p);
  }