src/arg.c - haproxy - Gitiles

 /*
  * Functions used to parse typed argument lists
  *
  * Copyright 2012 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  *
  */

 #include <sys/types.h>
 #include <sys/socket.h>
 #include <arpa/inet.h>

 #include <common/standard.h>
 #include <proto/arg.h>

 static const char *arg_type_names[ARGT_NBTYPES] = {
 	[ARGT_STOP] = "end of arguments",
 	[ARGT_UINT] = "unsigned integer",
 	[ARGT_SINT] = "signed integer",
 	[ARGT_STR]  = "string",
 	[ARGT_IPV4] = "IPv4 address",
 	[ARGT_MSK4] = "IPv4 mask",
 	[ARGT_IPV6] = "IPv6 address",
 	[ARGT_MSK6] = "IPv6 mask",
 	[ARGT_TIME] = "delay",
 	[ARGT_SIZE] = "size",
 	[ARGT_FE]   = "frontend",
 	[ARGT_BE]   = "backend",
 	[ARGT_TAB]  = "table",
 	[ARGT_SRV]  = "server",
 	[ARGT_USR]  = "user list",
 	[ARGT_MAP]  = "map",
 	/* Unassigned types must never happen. Better crash during parsing if they do. */
 };

 /* This dummy arg list may be used by default when no arg is found, it helps
  * parsers by removing pointer checks.
  */
 struct arg empty_arg_list[8] = { };

 /* This function clones a struct arg_list template into a new one which is
  * returned.
  */
 struct arg_list *arg_list_clone(const struct arg_list *orig)
 {
 	struct arg_list *new;

 	if ((new = calloc(1, sizeof(*new))) != NULL) {
 		/* ->list will be set by the caller when inserting the element.
 		 * ->arg and ->arg_pos will be set by the caller.
 		 */
 		new->ctx = orig->ctx;
 		new->kw = orig->kw;
 		new->conv = orig->conv;
 		new->file = orig->file;
 		new->line = orig->line;
 	}
 	return new;
 }

 /* This function clones a struct <arg_list> template into a new one which is
  * set to point to arg <arg> at pos <pos>, and which is returned if the caller
  * wants to apply further changes.
  */
 struct arg_list *arg_list_add(struct arg_list *orig, struct arg *arg, int pos)
 {
 	struct arg_list *new;

 	new = arg_list_clone(orig);
 	new->arg = arg;
 	new->arg_pos = pos;
 	LIST_ADDQ(&orig->list, &new->list);
 	return new;
 }

 /* This function builds an argument list from a config line. It returns the
  * number of arguments found, or <0 in case of any error. Everything needed
  * it automatically allocated. A pointer to an error message might be returned
  * in err_msg if not NULL, in which case it would be allocated and the caller
  * will have to check it and free it. The output arg list is returned in argp
  * which must be valid. The returned array is always terminated by an arg of
  * type ARGT_STOP (0), unless the mask indicates that no argument is supported.
  * Unresolved arguments are appended to arg list <al>, which also serves as a
  * template to create new entries. The mask is composed of a number of
  * mandatory arguments in its lower 4 bits, and a concatenation of each
  * argument type in each subsequent 4-bit block. If <err_msg> is not NULL, it
  * must point to a freeable or NULL pointer.
  */
 int make_arg_list(const char *in, int len, unsigned int mask, struct arg **argp,
                   char **err_msg, const char **err_ptr, int *err_arg,
                   struct arg_list *al)
 {
 	int nbarg;
 	int pos;
 	struct arg *arg;
 	const char *beg;
 	char *word = NULL;
 	const char *ptr_err = NULL;
 	int min_arg;

 	*argp = NULL;

 	min_arg = mask & 15;
 	mask >>= 4;

 	pos = 0;
 	/* find between 0 and 8 the max number of args supported by the mask */
 	for (nbarg = 0; nbarg < 8 && ((mask >> (nbarg * 4)) & 0xF); nbarg++);

 	if (!nbarg)
 		goto end_parse;

 	/* Note: an empty input string contains an empty argument if this argument
 	 * is marked mandatory. Otherwise we can ignore it.
 	 */
 	if (!len && !min_arg)
 		goto end_parse;

 	arg = *argp = calloc(nbarg + 1, sizeof(*arg));

 	/* Note: empty arguments after a comma always exist. */
 	while (pos < nbarg) {
 		beg = in;
 		while (len && *in != ',') {
 			in++;
 			len--;
 		}

 		/* we have a new argument between <beg> and <in> (not included).
 		 * For ease of handling, we copy it into a zero-terminated word.
 		 * By default, the output argument will be the same type of the
 		 * expected one.
 		 */
 		free(word);
 		word = my_strndup(beg, in - beg);

 		arg->type = (mask >> (pos * 4)) & 15;

 		switch (arg->type) {
 		case ARGT_SINT:
 			if (in == beg)	  // empty number
 				goto empty_err;
 			else if (*beg < '0' || *beg > '9') {
 				beg++;
 				arg->data.sint = read_uint(&beg, in);
 				if (beg < in)
 					goto parse_err;
 				if (*word == '-')
 					arg->data.sint = -arg->data.sint;
 				else if (*word != '+')    // invalid first character
 					goto parse_err;
 				break;
 			}

 			arg->type = ARGT_UINT;
 			/* fall through ARGT_UINT if no sign is present */

 		case ARGT_UINT:
 			if (in == beg)    // empty number
 				goto empty_err;

 			arg->data.uint = read_uint(&beg, in);
 			if (beg < in)
 				goto parse_err;
 			break;

 		case ARGT_FE:
 		case ARGT_BE:
 		case ARGT_TAB:
 		case ARGT_SRV:
 		case ARGT_USR:
 			/* These argument types need to be stored as strings during
 			 * parsing then resolved later.
 			 */
 			arg->unresolved = 1;
 			arg_list_add(al, arg, pos);

 			/* fall through */
 		case ARGT_STR:
 			/* all types that must be resolved are stored as strings
 			 * during the parsing. The caller must at one point resolve
 			 * them and free the string.
 			 */
 			arg->data.str.str = word;
 			arg->data.str.len = in - beg;
 			arg->data.str.size = arg->data.str.len + 1;
 			word = NULL;
 			break;

 		case ARGT_IPV4:
 			if (in == beg)    // empty address
 				goto empty_err;

 			if (inet_pton(AF_INET, word, &arg->data.ipv4) <= 0)
 				goto parse_err;
 			break;

 		case ARGT_MSK4:
 			if (in == beg)    // empty mask
 				goto empty_err;

 			if (!str2mask(word, &arg->data.ipv4))
 				goto parse_err;

 			arg->type = ARGT_IPV4;
 			break;

 		case ARGT_IPV6:
 			if (in == beg)    // empty address
 				goto empty_err;

 			if (inet_pton(AF_INET6, word, &arg->data.ipv6) <= 0)
 				goto parse_err;
 			break;

 		case ARGT_MSK6: /* not yet implemented */
 			goto not_impl;

 		case ARGT_TIME:
 			if (in == beg)    // empty time
 				goto empty_err;

 			ptr_err = parse_time_err(word, &arg->data.uint, TIME_UNIT_MS);
 			if (ptr_err)
 				goto parse_err;

 			arg->type = ARGT_UINT;
 			break;

 		case ARGT_SIZE:
 			if (in == beg)    // empty size
 				goto empty_err;

 			ptr_err = parse_size_err(word, &arg->data.uint);
 			if (ptr_err)
 				goto parse_err;

 			arg->type = ARGT_UINT;
 			break;

 			/* FIXME: other types need to be implemented here */
 		default:
 			goto not_impl;
 		}

 		pos++;
 		arg++;

 		/* don't go back to parsing if we reached end */
 		if (!len || pos >= nbarg)
 			break;

 		/* skip comma */
 		in++; len--;
 	}

  end_parse:
 	free(word); word = NULL;

 	if (pos < min_arg) {
 		/* not enough arguments */
 		memprintf(err_msg,
 		          "missing arguments (got %d/%d), type '%s' expected",
 		          pos, min_arg, arg_type_names[(mask >> (pos * 4)) & 15]);
 		goto err;
 	}

 	if (len) {
 		/* too many arguments, starting at <in> */
 		/* the caller is responsible for freeing this message */
 		word = my_strndup(in, len);
 		if (nbarg)
 			memprintf(err_msg, "end of arguments expected at position %d, but got '%s'",
 			          pos + 1, word);
 		else
 			memprintf(err_msg, "no argument supported, but got '%s'", word);
 		free(word); word = NULL;
 		goto err;
 	}

 	/* note that pos might be < nbarg and this is not an error, it's up to the
 	 * caller to decide what to do with optional args.
 	 */
 	if (err_arg)
 		*err_arg = pos;
 	if (err_ptr)
 		*err_ptr = in;
 	return pos;

  err:
 	free(word);
 	free(*argp);
 	*argp = NULL;
 	if (err_arg)
 		*err_arg = pos;
 	if (err_ptr)
 		*err_ptr = in;
 	return -1;

  empty_err:
 	memprintf(err_msg, "expected type '%s' at position %d, but got nothing",
 	          arg_type_names[(mask >> (pos * 4)) & 15], pos + 1);
 	goto err;

  parse_err:
 	memprintf(err_msg, "failed to parse '%s' as type '%s' at position %d",
 	          word, arg_type_names[(mask >> (pos * 4)) & 15], pos + 1);
 	goto err;

  not_impl:
 	memprintf(err_msg, "parsing for type '%s' was not implemented, please report this bug",
 	          arg_type_names[(mask >> (pos * 4)) & 15]);
 	goto err;
 }
	/*
	* Functions used to parse typed argument lists
	*
	* Copyright 2012 Willy Tarreau <w@1wt.eu>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*
	*/

	#include <sys/types.h>
	#include <sys/socket.h>
	#include <arpa/inet.h>

	#include <common/standard.h>
	#include <proto/arg.h>

	static const char *arg_type_names[ARGT_NBTYPES] = {
	[ARGT_STOP] = "end of arguments",
	[ARGT_UINT] = "unsigned integer",
	[ARGT_SINT] = "signed integer",
	[ARGT_STR] = "string",
	[ARGT_IPV4] = "IPv4 address",
	[ARGT_MSK4] = "IPv4 mask",
	[ARGT_IPV6] = "IPv6 address",
	[ARGT_MSK6] = "IPv6 mask",
	[ARGT_TIME] = "delay",
	[ARGT_SIZE] = "size",
	[ARGT_FE] = "frontend",
	[ARGT_BE] = "backend",
	[ARGT_TAB] = "table",
	[ARGT_SRV] = "server",
	[ARGT_USR] = "user list",
	[ARGT_MAP] = "map",
	/* Unassigned types must never happen. Better crash during parsing if they do. */
	};

	/* This dummy arg list may be used by default when no arg is found, it helps
	* parsers by removing pointer checks.
	*/
	struct arg empty_arg_list[8] = { };

	/* This function clones a struct arg_list template into a new one which is
	* returned.
	*/
	struct arg_list arg_list_clone(const struct arg_list orig)
	{
	struct arg_list *new;

	if ((new = calloc(1, sizeof(*new))) != NULL) {
	/* ->list will be set by the caller when inserting the element.
	* ->arg and ->arg_pos will be set by the caller.
	*/
	new->ctx = orig->ctx;
	new->kw = orig->kw;
	new->conv = orig->conv;
	new->file = orig->file;
	new->line = orig->line;
	}
	return new;
	}

	/* This function clones a struct <arg_list> template into a new one which is
	* set to point to arg <arg> at pos <pos>, and which is returned if the caller
	* wants to apply further changes.
	*/
	struct arg_list arg_list_add(struct arg_list orig, struct arg *arg, int pos)
	{
	struct arg_list *new;

	new = arg_list_clone(orig);
	new->arg = arg;
	new->arg_pos = pos;
	LIST_ADDQ(&orig->list, &new->list);
	return new;
	}

	/* This function builds an argument list from a config line. It returns the
	* number of arguments found, or <0 in case of any error. Everything needed
	* it automatically allocated. A pointer to an error message might be returned
	* in err_msg if not NULL, in which case it would be allocated and the caller
	* will have to check it and free it. The output arg list is returned in argp
	* which must be valid. The returned array is always terminated by an arg of
	* type ARGT_STOP (0), unless the mask indicates that no argument is supported.
	* Unresolved arguments are appended to arg list <al>, which also serves as a
	* template to create new entries. The mask is composed of a number of
	* mandatory arguments in its lower 4 bits, and a concatenation of each
	* argument type in each subsequent 4-bit block. If <err_msg> is not NULL, it
	* must point to a freeable or NULL pointer.
	*/
	int make_arg_list(const char in, int len, unsigned int mask, struct arg *argp,
	char err_msg, const char err_ptr, int *err_arg,
	struct arg_list *al)
	{
	int nbarg;
	int pos;
	struct arg *arg;
	const char *beg;
	char *word = NULL;
	const char *ptr_err = NULL;
	int min_arg;

	*argp = NULL;

	min_arg = mask & 15;
	mask >>= 4;

	pos = 0;
	/* find between 0 and 8 the max number of args supported by the mask */
	for (nbarg = 0; nbarg < 8 && ((mask >> (nbarg * 4)) & 0xF); nbarg++);

	if (!nbarg)
	goto end_parse;

	/* Note: an empty input string contains an empty argument if this argument
	* is marked mandatory. Otherwise we can ignore it.
	*/
	if (!len && !min_arg)
	goto end_parse;

	arg = argp = calloc(nbarg + 1, sizeof(arg));

	/* Note: empty arguments after a comma always exist. */
	while (pos < nbarg) {
	beg = in;
	while (len && *in != ',') {
	in++;
	len--;
	}

	/* we have a new argument between <beg> and <in> (not included).
	* For ease of handling, we copy it into a zero-terminated word.
	* By default, the output argument will be the same type of the
	* expected one.
	*/
	free(word);
	word = my_strndup(beg, in - beg);

	arg->type = (mask >> (pos * 4)) & 15;

	switch (arg->type) {
	case ARGT_SINT:
	if (in == beg) // empty number
	goto empty_err;
	else if (beg < '0' \|\| beg > '9') {
	beg++;
	arg->data.sint = read_uint(&beg, in);
	if (beg < in)
	goto parse_err;
	if (*word == '-')
	arg->data.sint = -arg->data.sint;
	else if (*word != '+') // invalid first character
	goto parse_err;
	break;
	}

	arg->type = ARGT_UINT;
	/* fall through ARGT_UINT if no sign is present */

	case ARGT_UINT:
	if (in == beg) // empty number
	goto empty_err;

	arg->data.uint = read_uint(&beg, in);
	if (beg < in)
	goto parse_err;
	break;

	case ARGT_FE:
	case ARGT_BE:
	case ARGT_TAB:
	case ARGT_SRV:
	case ARGT_USR:
	/* These argument types need to be stored as strings during
	* parsing then resolved later.
	*/
	arg->unresolved = 1;
	arg_list_add(al, arg, pos);

	/* fall through */
	case ARGT_STR:
	/* all types that must be resolved are stored as strings
	* during the parsing. The caller must at one point resolve
	* them and free the string.
	*/
	arg->data.str.str = word;
	arg->data.str.len = in - beg;
	arg->data.str.size = arg->data.str.len + 1;
	word = NULL;
	break;

	case ARGT_IPV4:
	if (in == beg) // empty address
	goto empty_err;

	if (inet_pton(AF_INET, word, &arg->data.ipv4) <= 0)
	goto parse_err;
	break;

	case ARGT_MSK4:
	if (in == beg) // empty mask
	goto empty_err;

	if (!str2mask(word, &arg->data.ipv4))
	goto parse_err;

	arg->type = ARGT_IPV4;
	break;

	case ARGT_IPV6:
	if (in == beg) // empty address
	goto empty_err;

	if (inet_pton(AF_INET6, word, &arg->data.ipv6) <= 0)
	goto parse_err;
	break;

	case ARGT_MSK6: /* not yet implemented */
	goto not_impl;

	case ARGT_TIME:
	if (in == beg) // empty time
	goto empty_err;

	ptr_err = parse_time_err(word, &arg->data.uint, TIME_UNIT_MS);
	if (ptr_err)
	goto parse_err;

	arg->type = ARGT_UINT;
	break;

	case ARGT_SIZE:
	if (in == beg) // empty size
	goto empty_err;

	ptr_err = parse_size_err(word, &arg->data.uint);
	if (ptr_err)
	goto parse_err;

	arg->type = ARGT_UINT;
	break;

	/* FIXME: other types need to be implemented here */
	default:
	goto not_impl;
	}

	pos++;
	arg++;

	/* don't go back to parsing if we reached end */
	if (!len \|\| pos >= nbarg)
	break;

	/* skip comma */
	in++; len--;
	}

	end_parse:
	free(word); word = NULL;

	if (pos < min_arg) {
	/* not enough arguments */
	memprintf(err_msg,
	"missing arguments (got %d/%d), type '%s' expected",
	pos, min_arg, arg_type_names[(mask >> (pos * 4)) & 15]);
	goto err;
	}

	if (len) {
	/* too many arguments, starting at <in> */
	/* the caller is responsible for freeing this message */
	word = my_strndup(in, len);
	if (nbarg)
	memprintf(err_msg, "end of arguments expected at position %d, but got '%s'",
	pos + 1, word);
	else
	memprintf(err_msg, "no argument supported, but got '%s'", word);
	free(word); word = NULL;
	goto err;
	}

	/* note that pos might be < nbarg and this is not an error, it's up to the
	* caller to decide what to do with optional args.
	*/
	if (err_arg)
	*err_arg = pos;
	if (err_ptr)
	*err_ptr = in;
	return pos;

	err:
	free(word);
	free(*argp);
	*argp = NULL;
	if (err_arg)
	*err_arg = pos;
	if (err_ptr)
	*err_ptr = in;
	return -1;

	empty_err:
	memprintf(err_msg, "expected type '%s' at position %d, but got nothing",
	arg_type_names[(mask >> (pos * 4)) & 15], pos + 1);
	goto err;

	parse_err:
	memprintf(err_msg, "failed to parse '%s' as type '%s' at position %d",
	word, arg_type_names[(mask >> (pos * 4)) & 15], pos + 1);
	goto err;

	not_impl:
	memprintf(err_msg, "parsing for type '%s' was not implemented, please report this bug",
	arg_type_names[(mask >> (pos * 4)) & 15]);
	goto err;
	}