blob: 90742265cc477ac06cb6d01d24241b2ca9246420 [file] [log] [blame]
/*
* 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 <common/chunk.h>
#include <types/global.h>
#include <proto/arg.h>
const char *arg_type_names[ARGT_NBTYPES] = {
[ARGT_STOP] = "end of arguments",
[ARGT_SINT] = "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",
[ARGT_REG] = "regex",
[ARGT_VAR] = "variable",
[ARGT_PBUF_FNUM] = "Protocol buffers field number",
/* 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[ARGM_NBARGS] = { };
/* 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);
if (new) {
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, and stops at the
* first non-matching character, which is pointed to in <end_ptr>. A valid arg
* list starts with an opening parenthesis '(', contains a number of comma-
* delimited words, and ends with the closing parenthesis ')'. An empty list
* (with or without the parenthesis) will lead to a valid empty argument if the
* keyword has a mandatory one. The function returns the number of arguments
* emitted, 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
* ARGM_BITS bits, and a concatenation of each argument type in each subsequent
* ARGT_BITS-bit sblock. If <err_msg> is not NULL, it must point to a freeable
* or NULL pointer. The caller is expected to restart the parsing from the new
* pointer set in <end_ptr>, which is the first character considered as not
* being part of the arg list. The input string ends on the first between <len>
* characters (when len is positive) or the first NUL character. Placing -1 in
* <len> will make it virtually unbounded (~2GB long strings).
*/
int make_arg_list(const char *in, int len, uint64_t mask, struct arg **argp,
char **err_msg, const char **end_ptr, int *err_arg,
struct arg_list *al)
{
int nbarg;
int pos;
struct arg *arg;
const char *beg;
const char *ptr_err = NULL;
int min_arg;
int empty;
struct arg_list *new_al = al;
*argp = NULL;
empty = 0;
if (!len || *in != '(') {
/* it's already not for us, stop here */
empty = 1;
len = 0;
} else {
/* skip opening parenthesis */
len--;
in++;
}
min_arg = mask & ARGM_MASK;
mask >>= ARGM_BITS;
pos = 0;
/* find between 0 and NBARGS the max number of args supported by the mask */
for (nbarg = 0; nbarg < ARGM_NBARGS && ((mask >> (nbarg * ARGT_BITS)) & ARGT_MASK); 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 (empty && !min_arg)
goto end_parse;
arg = *argp = calloc(nbarg + 1, sizeof(*arg));
/* Note: empty arguments after a comma always exist. */
while (pos < nbarg) {
unsigned int uint;
int squote = 0, dquote = 0;
char *out;
chunk_reset(&trash);
out = trash.area;
while (len && *in && trash.data < trash.size - 1) {
if (*in == '"' && !squote) { /* double quote outside single quotes */
if (dquote)
dquote = 0;
else
dquote = 1;
in++; len--;
continue;
}
else if (*in == '\'' && !dquote) { /* single quote outside double quotes */
if (squote)
squote = 0;
else
squote = 1;
in++; len--;
continue;
}
else if (*in == '\\' && !squote && len != 1) {
/* '\', ', ' ', '"' support being escaped by '\' */
if (len == 1 || in[1] == 0)
goto unquote_err;
if (in[1] == '\\' || in[1] == ' ' || in[1] == '"' || in[1] == '\'') {
in++; len--;
*out++ = *in;
}
else if (in[1] == 'r') {
in++; len--;
*out++ = '\r';
}
else if (in[1] == 'n') {
in++; len--;
*out++ = '\n';
}
else if (in[1] == 't') {
in++; len--;
*out++ = '\t';
}
else {
/* just a lone '\' */
*out++ = *in;
}
in++; len--;
}
else {
if (!squote && !dquote && (*in == ',' || *in == ')')) {
/* end of argument */
break;
}
/* verbatim copy */
*out++ = *in++;
len--;
}
trash.data = out - trash.area;
}
if (len && *in && *in != ',' && *in != ')')
goto buffer_err;
trash.area[trash.data] = 0;
arg->type = (mask >> (pos * ARGT_BITS)) & ARGT_MASK;
switch (arg->type) {
case ARGT_SINT:
if (!trash.data) // empty number
goto empty_err;
beg = trash.area;
arg->data.sint = read_int64(&beg, trash.area + trash.data);
if (beg < trash.area + trash.data)
goto parse_err;
arg->type = ARGT_SINT;
break;
case ARGT_FE:
case ARGT_BE:
case ARGT_TAB:
case ARGT_SRV:
case ARGT_USR:
case ARGT_REG:
/* These argument types need to be stored as strings during
* parsing then resolved later.
*/
arg->unresolved = 1;
new_al = 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.area = my_strndup(trash.area, trash.data);
arg->data.str.data = trash.data;
arg->data.str.size = trash.data + 1;
break;
case ARGT_IPV4:
if (!trash.data) // empty address
goto empty_err;
if (inet_pton(AF_INET, trash.area, &arg->data.ipv4) <= 0)
goto parse_err;
break;
case ARGT_MSK4:
if (!trash.data) // empty mask
goto empty_err;
if (!str2mask(trash.area, &arg->data.ipv4))
goto parse_err;
arg->type = ARGT_IPV4;
break;
case ARGT_IPV6:
if (!trash.data) // empty address
goto empty_err;
if (inet_pton(AF_INET6, trash.area, &arg->data.ipv6) <= 0)
goto parse_err;
break;
case ARGT_MSK6:
if (!trash.data) // empty mask
goto empty_err;
if (!str2mask6(trash.area, &arg->data.ipv6))
goto parse_err;
arg->type = ARGT_IPV6;
break;
case ARGT_TIME:
if (!trash.data) // empty time
goto empty_err;
ptr_err = parse_time_err(trash.area, &uint, TIME_UNIT_MS);
if (ptr_err) {
if (ptr_err == PARSE_TIME_OVER || ptr_err == PARSE_TIME_UNDER)
ptr_err = trash.area;
goto parse_err;
}
arg->data.sint = uint;
arg->type = ARGT_SINT;
break;
case ARGT_SIZE:
if (!trash.data) // empty size
goto empty_err;
ptr_err = parse_size_err(trash.area, &uint);
if (ptr_err)
goto parse_err;
arg->data.sint = uint;
arg->type = ARGT_SINT;
break;
case ARGT_PBUF_FNUM:
if (!trash.data)
goto empty_err;
if (!parse_dotted_uints(trash.area, &arg->data.fid.ids, &arg->data.fid.sz))
goto parse_err;
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 || !*in || *in == ')' || pos >= nbarg)
break;
/* skip comma */
in++; len--;
}
end_parse:
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 * ARGT_BITS)) & ARGT_MASK]);
goto err;
}
if (empty) {
/* nothing to do */
} else if (*in == ')') {
/* skip the expected closing parenthesis */
in++;
} else {
/* the caller is responsible for freeing this message */
char *word = (len > 0) ? my_strndup(in, len) : (char *)in;
memprintf(err_msg, "expected ')' before '%s'", word);
if (len > 0)
free(word);
/* when we're missing a right paren, the empty part preceeding
* already created an empty arg, adding one to the position, so
* let's fix the reporting to avoid being confusing.
*/
if (pos > 1)
pos--;
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 (end_ptr)
*end_ptr = in;
return pos;
err:
if (new_al == al) {
/* only free the arg area if we have not queued unresolved args
* still pointing to it.
*/
free(*argp);
}
*argp = NULL;
if (err_arg)
*err_arg = pos;
if (end_ptr)
*end_ptr = in;
return -1;
empty_err:
memprintf(err_msg, "expected type '%s' at position %d, but got nothing",
arg_type_names[(mask >> (pos * ARGT_BITS)) & ARGT_MASK], pos + 1);
goto err;
parse_err:
/* come here with the word attempted to parse in trash */
memprintf(err_msg, "failed to parse '%s' as type '%s' at position %d",
trash.area, arg_type_names[(mask >> (pos * ARGT_BITS)) & ARGT_MASK], 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 * ARGT_BITS)) & ARGT_MASK]);
goto err;
buffer_err:
memprintf(err_msg, "too small buffer size to store decoded argument %d, increase bufsize ?",
pos + 1);
goto err;
unquote_err:
/* come here with the parsed part in <trash.area>:<trash.data> and the
* unparsable part in <in>.
*/
trash.area[trash.data] = 0;
memprintf(err_msg, "failed to parse '%s' after '%s' as type '%s' at position %d",
in, trash.area, arg_type_names[(mask >> (pos * ARGT_BITS)) & ARGT_MASK], pos + 1);
goto err;
}