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/*
* Sample management functions.
*
* Copyright 2009-2010 EXCELIANCE, Emeric Brun <ebrun@exceliance.fr>
* Copyright (C) 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 <string.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <common/chunk.h>
#include <common/standard.h>
#include <proto/arg.h>
#include <proto/sample.h>
/* static sample used in sample_process() when <p> is NULL */
static struct sample temp_smp;
/* trash chunk used for sample conversions */
static struct chunk trash_chunk;
/* trash buffers used or sample conversions */
static char sample_trash_buf1[BUFSIZE];
static char sample_trash_buf2[BUFSIZE];
/* sample_trash_buf point on used buffer*/
static char *sample_trash_buf = sample_trash_buf1;
/* list head of all known sample fetch keywords */
static struct sample_fetch_kw_list sample_fetches = {
.list = LIST_HEAD_INIT(sample_fetches.list)
};
/* list head of all known sample format conversion keywords */
static struct sample_conv_kw_list sample_convs = {
.list = LIST_HEAD_INIT(sample_convs.list)
};
/*
* Registers the sample fetch keyword list <kwl> as a list of valid keywords for next
* parsing sessions.
*/
void sample_register_fetches(struct sample_fetch_kw_list *pfkl)
{
LIST_ADDQ(&sample_fetches.list, &pfkl->list);
}
/*
* Registers the sample format coverstion keyword list <pckl> as a list of valid keywords for next
* parsing sessions.
*/
void sample_register_convs(struct sample_conv_kw_list *pckl)
{
LIST_ADDQ(&sample_convs.list, &pckl->list);
}
/*
* Returns the pointer on sample fetch keyword structure identified by
* string of <len> in buffer <kw>.
*
*/
struct sample_fetch *find_sample_fetch(const char *kw, int len)
{
int index;
struct sample_fetch_kw_list *kwl;
list_for_each_entry(kwl, &sample_fetches.list, list) {
for (index = 0; kwl->kw[index].kw != NULL; index++) {
if (strncmp(kwl->kw[index].kw, kw, len) == 0 &&
kwl->kw[index].kw[len] == '\0')
return &kwl->kw[index];
}
}
return NULL;
}
/*
* Returns the pointer on sample format conversion keyword structure identified by
* string of <len> in buffer <kw>.
*
*/
struct sample_conv *find_sample_conv(const char *kw, int len)
{
int index;
struct sample_conv_kw_list *kwl;
list_for_each_entry(kwl, &sample_convs.list, list) {
for (index = 0; kwl->kw[index].kw != NULL; index++) {
if (strncmp(kwl->kw[index].kw, kw, len) == 0 &&
kwl->kw[index].kw[len] == '\0')
return &kwl->kw[index];
}
}
return NULL;
}
/*
* Returns a static trash struct chunk to use in sample casts or format conversions
* Swiths the 2 available trash buffers to protect data during convert
*/
struct chunk *sample_get_trash_chunk(void)
{
if (sample_trash_buf == sample_trash_buf1)
sample_trash_buf = sample_trash_buf2;
else
sample_trash_buf = sample_trash_buf1;
chunk_init(&trash_chunk, sample_trash_buf, BUFSIZE);
return &trash_chunk;
}
/******************************************************************/
/* Sample casts functions */
/* Note: these functions do *NOT* set the output type on the */
/* sample, the caller is responsible for doing this on return. */
/******************************************************************/
static int c_ip2int(struct sample *smp)
{
smp->data.uint = ntohl(smp->data.ipv4.s_addr);
return 1;
}
static int c_ip2str(struct sample *smp)
{
struct chunk *trash = sample_get_trash_chunk();
if (!inet_ntop(AF_INET, (void *)&smp->data.ipv4, trash->str, trash->size))
return 0;
trash->len = strlen(trash->str);
smp->data.str = *trash;
return 1;
}
static int c_ip2ipv6(struct sample *smp)
{
v4tov6(&smp->data.ipv6, &smp->data.ipv4);
return 1;
}
static int c_ipv62str(struct sample *smp)
{
struct chunk *trash = sample_get_trash_chunk();
if (!inet_ntop(AF_INET6, (void *)&smp->data.ipv6, trash->str, trash->size))
return 0;
trash->len = strlen(trash->str);
smp->data.str = *trash;
return 1;
}
/*
static int c_ipv62ip(struct sample *smp)
{
return v6tov4(&smp->data.ipv4, &smp->data.ipv6);
}
*/
static int c_int2ip(struct sample *smp)
{
smp->data.ipv4.s_addr = htonl(smp->data.uint);
return 1;
}
static int c_str2ip(struct sample *smp)
{
if (!buf2ip(smp->data.str.str, smp->data.str.len, &smp->data.ipv4))
return 0;
return 1;
}
static int c_str2ipv6(struct sample *smp)
{
return inet_pton(AF_INET6, smp->data.str.str, &smp->data.ipv6);
}
static int c_bin2str(struct sample *smp)
{
struct chunk *trash = sample_get_trash_chunk();
unsigned char c;
int ptr = 0;
trash->len = 0;
while (ptr < smp->data.str.len && trash->len <= trash->size - 2) {
c = smp->data.str.str[ptr++];
trash->str[trash->len++] = hextab[(c >> 4) & 0xF];
trash->str[trash->len++] = hextab[c & 0xF];
}
smp->data.str = *trash;
return 1;
}
static int c_int2str(struct sample *smp)
{
struct chunk *trash = sample_get_trash_chunk();
char *pos;
pos = ultoa_r(smp->data.uint, trash->str, trash->size);
if (!pos)
return 0;
trash->size = trash->size - (pos - trash->str);
trash->str = pos;
trash->len = strlen(pos);
smp->data.str = *trash;
return 1;
}
static int c_datadup(struct sample *smp)
{
struct chunk *trash = sample_get_trash_chunk();
trash->len = smp->data.str.len < trash->size ? smp->data.str.len : trash->size;
memcpy(trash->str, smp->data.str.str, trash->len);
smp->data.str = *trash;
return 1;
}
static int c_none(struct sample *smp)
{
return 1;
}
static int c_str2int(struct sample *smp)
{
int i;
uint32_t ret = 0;
for (i = 0; i < smp->data.str.len; i++) {
uint32_t val = smp->data.str.str[i] - '0';
if (val > 9)
break;
ret = ret * 10 + val;
}
smp->data.uint = ret;
return 1;
}
/*****************************************************************/
/* Sample casts matrix: */
/* sample_casts[from type][to type] */
/* NULL pointer used for impossible sample casts */
/*****************************************************************/
typedef int (*sample_cast_fct)(struct sample *smp);
static sample_cast_fct sample_casts[SMP_TYPES][SMP_TYPES] = {
/* to: BOOL UINT SINT IPV4 IPV6 STR BIN CSTR CBIN */
/* from: BOOL */ { c_none, c_none, c_none, NULL, NULL, NULL, NULL, NULL, NULL },
/* UINT */ { c_none, c_none, c_none, c_int2ip, NULL, c_int2str, NULL, c_int2str, NULL },
/* SINT */ { c_none, c_none, c_none, c_int2ip, NULL, c_int2str, NULL, c_int2str, NULL },
/* IPV4 */ { NULL, c_ip2int, c_ip2int, c_none, c_ip2ipv6, c_ip2str, NULL, c_ip2str, NULL },
/* IPV6 */ { NULL, NULL, NULL, NULL, c_none, c_ipv62str, NULL, c_ipv62str, NULL },
/* STR */ { c_str2int, c_str2int, c_str2int, c_str2ip, c_str2ipv6, c_none, c_none, c_none, c_none },
/* BIN */ { NULL, NULL, NULL, NULL, NULL, c_bin2str, c_none, c_bin2str, c_none },
/* CSTR */ { c_str2int, c_str2int, c_str2int, c_str2ip, c_str2ipv6, c_datadup, c_datadup, c_none, c_none },
/* CBIN */ { NULL, NULL, NULL, NULL, NULL, c_bin2str, c_datadup, c_bin2str, c_none },
};
/*
* Parse a sample expression configuration:
* fetch keyword followed by format conversion keywords.
* Returns a pointer on allocated sample expression structure.
*/
struct sample_expr *sample_parse_expr(char **str, int *idx, char *err, int err_size)
{
const char *endw;
const char *end;
struct sample_expr *expr;
struct sample_fetch *fetch;
struct sample_conv *conv;
unsigned long prev_type;
char *p;
snprintf(err, err_size, "memory error.");
if (!str[*idx]) {
snprintf(err, err_size, "missing fetch method.");
goto out_error;
}
end = str[*idx] + strlen(str[*idx]);
endw = strchr(str[*idx], '(');
if (!endw)
endw = end;
else if ((end-1)[0] != ')') {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "syntax error: missing ')' after keyword '%s'.", p);
free(p);
}
goto out_error;
}
fetch = find_sample_fetch(str[*idx], endw - str[*idx]);
if (!fetch) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "unknown fetch method '%s'.", p);
free(p);
}
goto out_error;
}
if (fetch->out_type >= SMP_TYPES) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "returns type of fetch method '%s' is unknown.", p);
free(p);
}
goto out_error;
}
prev_type = fetch->out_type;
expr = calloc(1, sizeof(struct sample_expr));
if (!expr)
goto out_error;
LIST_INIT(&(expr->conv_exprs));
expr->fetch = fetch;
expr->arg_p = empty_arg_list;
if (end != endw) {
char *err_msg = NULL;
int err_arg;
if (!fetch->arg_mask) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "fetch method '%s' does not support any args.", p);
free(p);
}
goto out_error;
}
if (make_arg_list(endw + 1, end - endw - 2, fetch->arg_mask, &expr->arg_p, &err_msg, NULL, &err_arg) < 0) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "invalid arg %d in fetch method '%s' : %s.", err_arg+1, p, err_msg);
free(p);
}
free(err_msg);
goto out_error;
}
if (!expr->arg_p)
expr->arg_p = empty_arg_list;
if (fetch->val_args && !fetch->val_args(expr->arg_p, &err_msg)) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "invalid args in fetch method '%s' : %s.", p, err_msg);
free(p);
}
free(err_msg);
goto out_error;
}
}
else if (ARGM(fetch->arg_mask)) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "missing args for fetch method '%s'.", p);
free(p);
}
goto out_error;
}
for (*idx += 1; *(str[*idx]); (*idx)++) {
struct sample_conv_expr *conv_expr;
end = str[*idx] + strlen(str[*idx]);
endw = strchr(str[*idx], '(');
if (!endw)
endw = end;
else if ((end-1)[0] != ')') {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "syntax error, missing ')' after keyword '%s'.", p);
free(p);
}
goto out_error;
}
conv = find_sample_conv(str[*idx], endw - str[*idx]);
if (!conv)
break;
if (conv->in_type >= SMP_TYPES ||
conv->out_type >= SMP_TYPES) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "returns type of conv method '%s' is unknown.", p);
free(p);
}
goto out_error;
}
/* If impossible type conversion */
if (!sample_casts[prev_type][conv->in_type]) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "conv method '%s' cannot be applied.", p);
free(p);
}
goto out_error;
}
prev_type = conv->out_type;
conv_expr = calloc(1, sizeof(struct sample_conv_expr));
if (!conv_expr)
goto out_error;
LIST_ADDQ(&(expr->conv_exprs), &(conv_expr->list));
conv_expr->conv = conv;
if (end != endw) {
char *err_msg = NULL;
int err_arg;
if (!conv->arg_mask) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "conv method '%s' does not support any args.", p);
free(p);
}
goto out_error;
}
if (make_arg_list(endw + 1, end - endw - 2, conv->arg_mask, &conv_expr->arg_p, &err_msg, NULL, &err_arg) < 0) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "invalid arg %d in conv method '%s' : %s.", err_arg+1, p, err_msg);
free(p);
}
free(err_msg);
goto out_error;
}
if (!conv_expr->arg_p)
conv_expr->arg_p = empty_arg_list;
if (conv->val_args && !conv->val_args(conv_expr->arg_p, &err_msg)) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "invalid args in conv method '%s' : %s.", p, err_msg);
free(p);
}
free(err_msg);
goto out_error;
}
}
else if (conv->arg_mask) {
p = my_strndup(str[*idx], endw - str[*idx]);
if (p) {
snprintf(err, err_size, "missing args for conv method '%s'.", p);
free(p);
}
goto out_error;
}
}
return expr;
out_error:
/* TODO: prune_sample_expr(expr); */
return NULL;
}
/*
* Process a fetch + format conversion of defined by the sample expression <expr>
* on request or response considering the <opt> parameter.
* Returns a pointer on a typed sample structure containing the result or NULL if
* sample is not found or when format conversion failed.
* If <p> is not null, function returns results in structure pointed by <p>.
* If <p> is null, functions returns a pointer on a static sample structure.
*
* Note: the fetch functions are required to properly set the return type. The
* conversion functions must do so too. However the cast functions do not need
* to since they're made to cast mutiple types according to what is required.
*/
struct sample *sample_process(struct proxy *px, struct session *l4, void *l7,
unsigned int opt,
struct sample_expr *expr, struct sample *p)
{
struct sample_conv_expr *conv_expr;
if (p == NULL)
p = &temp_smp;
p->flags = 0;
if (!expr->fetch->process(px, l4, l7, opt, expr->arg_p, p))
return NULL;
if (p->flags & SMP_F_MAY_CHANGE)
return NULL; /* we can only use stable samples */
list_for_each_entry(conv_expr, &expr->conv_exprs, list) {
/* we want to ensure that p->type can be casted into
* conv_expr->conv->in_type. We have 3 possibilities :
* - NULL => not castable.
* - c_none => nothing to do (let's optimize it)
* - other => apply cast and prepare to fail
*/
if (!sample_casts[p->type][conv_expr->conv->in_type])
return NULL;
if (sample_casts[p->type][conv_expr->conv->in_type] != c_none &&
!sample_casts[p->type][conv_expr->conv->in_type](p))
return NULL;
/* OK cast succeeded */
/* force the output type after a cast */
p->type = conv_expr->conv->in_type;
if (!conv_expr->conv->process(conv_expr->arg_p, p))
return NULL;
}
return p;
}
/*****************************************************************/
/* Sample format convert functions */
/* These functions set the data type on return. */
/*****************************************************************/
static int sample_conv_str2lower(const struct arg *arg_p, struct sample *smp)
{
int i;
if (!smp->data.str.size)
return 0;
for (i = 0; i < smp->data.str.len; i++) {
if ((smp->data.str.str[i] >= 'A') && (smp->data.str.str[i] <= 'Z'))
smp->data.str.str[i] += 'a' - 'A';
}
smp->type = SMP_T_STR;
return 1;
}
static int sample_conv_str2upper(const struct arg *arg_p, struct sample *smp)
{
int i;
if (!smp->data.str.size)
return 0;
for (i = 0; i < smp->data.str.len; i++) {
if ((smp->data.str.str[i] >= 'a') && (smp->data.str.str[i] <= 'z'))
smp->data.str.str[i] += 'A' - 'a';
}
smp->type = SMP_T_STR;
return 1;
}
/* takes the netmask in arg_p */
static int sample_conv_ipmask(const struct arg *arg_p, struct sample *smp)
{
smp->data.ipv4.s_addr &= arg_p->data.ipv4.s_addr;
smp->type = SMP_T_IPV4;
return 1;
}
/* Note: must not be declared <const> as its list will be overwritten */
static struct sample_conv_kw_list sample_conv_kws = {{ },{
{ "upper", sample_conv_str2upper, 0, NULL, SMP_T_STR, SMP_T_STR },
{ "lower", sample_conv_str2lower, 0, NULL, SMP_T_STR, SMP_T_STR },
{ "ipmask", sample_conv_ipmask, ARG1(1,MSK4), NULL, SMP_T_IPV4, SMP_T_IPV4 },
{ NULL, NULL, 0, 0, 0 },
}};
__attribute__((constructor))
static void __sample_init(void)
{
/* register sample format convert keywords */
sample_register_convs(&sample_conv_kws);
}