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/*
* Patterns management functions.
*
* Copyright 2009-2010 EXCELIANCE, Emeric Brun <ebrun@exceliance.fr>
*
* 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 <types/stick_table.h>
#include <proto/pattern.h>
#include <common/standard.h>
/* static structure used on pattern_process if <p> is NULL*/
static struct pattern spattern;
/* trash chunk used for pattern conversions */
static struct chunk trash_chunk;
/* trash buffers used or pattern conversions */
static char pattern_trash_buf1[BUFSIZE];
static char pattern_trash_buf2[BUFSIZE];
/* pattern_trash_buf point on used buffer*/
static char *pattern_trash_buf = pattern_trash_buf1;
/* static structure used to returns builded table key from a pattern*/
static struct stktable_key stable_key;
/* list head of all known pattern fetch keywords */
static struct pattern_fetch_kw_list pattern_fetches = {
.list = LIST_HEAD_INIT(pattern_fetches.list)
};
/* list head of all known pattern format conversion keywords */
static struct pattern_conv_kw_list pattern_convs = {
.list = LIST_HEAD_INIT(pattern_convs.list)
};
/*
* Registers the pattern fetch keyword list <kwl> as a list of valid keywords for next
* parsing sessions.
*/
void pattern_register_fetches(struct pattern_fetch_kw_list *pfkl)
{
LIST_ADDQ(&pattern_fetches.list, &pfkl->list);
}
/*
* Registers the pattern format coverstion keyword list <pckl> as a list of valid keywords for next
* parsing sessions.
*/
void pattern_register_convs(struct pattern_conv_kw_list *pckl)
{
LIST_ADDQ(&pattern_convs.list, &pckl->list);
}
/*
* Returns the pointer on pattern fetch keyword structure identified by
* string of <len> in buffer <kw>.
*
*/
struct pattern_fetch *find_pattern_fetch(const char *kw, int len)
{
int index;
struct pattern_fetch_kw_list *kwl;
list_for_each_entry(kwl, &pattern_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 pattern format conversion keyword structure identified by
* string of <len> in buffer <kw>.
*
*/
struct pattern_conv *find_pattern_conv(const char *kw, int len)
{
int index;
struct pattern_conv_kw_list *kwl;
list_for_each_entry(kwl, &pattern_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 pattern casts or format conversions
* Swiths the 2 available trash buffers to protect data during convert
*/
static struct chunk *get_trash_chunk(void)
{
if (pattern_trash_buf == pattern_trash_buf1)
pattern_trash_buf = pattern_trash_buf2;
else
pattern_trash_buf = pattern_trash_buf1;
trash_chunk.str = pattern_trash_buf;
trash_chunk.len = 0;
trash_chunk.size = BUFSIZE;
return &trash_chunk;
}
/*
* Used to set pattern data from a struct chunk, could be the trash struct chunk
*/
static void pattern_data_setstring(union pattern_data *data, struct chunk *c)
{
data->str.str = c->str;
data->str.len = c->len;
data->str.size = c->size;
}
/******************************************************************/
/* Pattern casts functions */
/******************************************************************/
static int c_ip2int(union pattern_data *data)
{
data->integer = ntohl(data->ip.s_addr);
return 1;
}
static int c_ip2str(union pattern_data *data)
{
struct chunk *trash = get_trash_chunk();
if (!inet_ntop(AF_INET, (void *)&data->ip, trash->str, trash->size))
return 0;
trash->len = strlen(trash->str);
pattern_data_setstring(data, trash);
return 1;
}
static int c_int2ip(union pattern_data *data)
{
data->ip.s_addr = htonl(data->integer);
return 1;
}
/* Convert a fixed-length string to an IP address. Returns 0 in case of error,
* or the number of chars read in case of success.
*/
static int buf2ip(const char *buf, size_t len, struct in_addr *dst)
{
const char *addr;
int saw_digit, octets, ch;
u_char tmp[4], *tp;
const char *cp = buf;
saw_digit = 0;
octets = 0;
*(tp = tmp) = 0;
for (addr = buf; addr - buf < len; addr++) {
unsigned char digit = (ch = *addr) - '0';
if (digit > 9 && ch != '.')
break;
if (digit <= 9) {
u_int new = *tp * 10 + digit;
if (new > 255)
return 0;
*tp = new;
if (!saw_digit) {
if (++octets > 4)
return 0;
saw_digit = 1;
}
} else if (ch == '.' && saw_digit) {
if (octets == 4)
return 0;
*++tp = 0;
saw_digit = 0;
} else
return 0;
}
if (octets < 4)
return 0;
memcpy(&dst->s_addr, tmp, 4);
return addr - cp;
}
static int c_str2ip(union pattern_data *data)
{
if (!buf2ip(data->str.str, data->str.len, &data->ip))
return 0;
return 1;
}
static int c_int2str(union pattern_data *data)
{
struct chunk *trash = get_trash_chunk();
char *pos;
pos = ultoa_r(data->integer, trash->str, trash->size);
if (!pos)
return 0;
trash->str = pos;
trash->len = strlen(pos);
pattern_data_setstring(data, trash);
return 1;
}
static int c_donothing(union pattern_data *data)
{
return 1;
}
static int c_str2int(union pattern_data *data)
{
int i;
uint32_t ret = 0;
for (i = 0; i < data->str.len; i++) {
uint32_t val = data->str.str[i] - '0';
if (val > 9)
break;
ret = ret * 10 + val;
}
data->integer = ret;
return 1;
}
/*****************************************************************/
/* Pattern casts matrix: */
/* pattern_casts[from type][to type] */
/* NULL pointer used for impossible pattern casts */
/*****************************************************************/
typedef int (*pattern_cast)(union pattern_data *data);
static pattern_cast pattern_casts[PATTERN_TYPES][PATTERN_TYPES] = { { c_donothing, c_ip2int, c_ip2str },
{ c_int2ip, c_donothing, c_int2str },
{ c_str2ip, c_str2int, c_donothing } };
/*****************************************************************/
/* typed pattern to typed table key functions */
/*****************************************************************/
static void *k_int2int(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
return (void *)&pdata->integer;
}
static void *k_ip2ip(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
return (void *)&pdata->ip.s_addr;
}
static void *k_ip2int(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
kdata->integer = ntohl(pdata->ip.s_addr);
return (void *)&kdata->integer;
}
static void *k_int2ip(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
kdata->ip.s_addr = htonl(pdata->integer);
return (void *)&kdata->ip.s_addr;
}
static void *k_str2str(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
*len = pdata->str.len;
return (void *)pdata->str.str;
}
static void *k_ip2str(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
if (!inet_ntop(AF_INET, &pdata->ip, kdata->buf, sizeof(kdata->buf)))
return NULL;
*len = strlen((const char *)kdata->buf);
return (void *)kdata->buf;
}
static void *k_int2str(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
void *key;
key = (void *)ultoa_r(pdata->integer, kdata->buf, sizeof(kdata->buf));
if (!key)
return NULL;
*len = strlen((const char *)key);
return key;
}
static void *k_str2ip(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
if (!buf2ip(pdata->str.str, pdata->str.len, &kdata->ip))
return NULL;
return (void *)&kdata->ip.s_addr;
}
static void *k_str2int(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len)
{
int i;
kdata->integer = 0;
for (i = 0; i < pdata->str.len; i++) {
uint32_t val = pdata->str.str[i] - '0';
if (val > 9)
break;
kdata->integer = kdata->integer * 10 + val;
}
return (void *)&kdata->integer;
}
/*****************************************************************/
/* typed pattern to typed table key matrix: */
/* pattern_keys[from pattern type][to table key type] */
/* NULL pointer used for impossible pattern casts */
/*****************************************************************/
typedef void *(*pattern_key)(union pattern_data *pdata, union stktable_key_data *kdata, size_t *len);
static pattern_key pattern_keys[PATTERN_TYPES][STKTABLE_TYPES] = { { k_ip2ip, k_ip2int, k_ip2str },
{ k_int2ip, k_int2int, k_int2str },
{ k_str2ip, k_str2int, k_str2str } };
/*
* Parse a pattern expression configuration:
* fetch keyword followed by format conversion keywords.
* Returns a pointer on allocated pattern expression structure.
*/
struct pattern_expr *pattern_parse_expr(char **str, int *idx)
{
const char *endw;
const char *end;
struct pattern_expr *expr;
struct pattern_fetch *fetch;
struct pattern_conv *conv;
unsigned long prev_type;
if (!str[*idx])
goto out_error;
end = str[*idx] + strlen(str[*idx]);
endw = strchr(str[*idx], '(');
if (!endw)
endw = end;
else if ((end-1)[0] != ')')
goto out_error;
fetch = find_pattern_fetch(str[*idx], endw - str[*idx]);
if (!fetch)
goto out_error;
if (fetch->out_type >= PATTERN_TYPES)
goto out_error;
prev_type = fetch->out_type;
expr = calloc(1, sizeof(struct pattern_expr));
LIST_INIT(&(expr->conv_exprs));
expr->fetch = fetch;
if (end != endw) {
expr->arg_len = end - endw - 2;
expr->arg = my_strndup(endw + 1, expr->arg_len);
}
for (*idx += 1; *(str[*idx]); (*idx)++) {
struct pattern_conv_expr *conv_expr;
end = str[*idx] + strlen(str[*idx]);
endw = strchr(str[*idx], '(');
if (!endw)
endw = end;
else if ((end-1)[0] != ')')
goto out_error;
conv = find_pattern_conv(str[*idx], endw - str[*idx]);
if (!conv)
break;
if (conv->in_type >= PATTERN_TYPES ||
conv->out_type >= PATTERN_TYPES)
goto out_error;
/* If impossible type conversion */
if (!pattern_casts[prev_type][conv->in_type])
goto out_error;
prev_type = conv->out_type;
conv_expr = calloc(1, sizeof(struct pattern_conv_expr));
LIST_ADDQ(&(expr->conv_exprs), &(conv_expr->list));
conv_expr->conv = conv;
if (end != endw) {
int i = end - endw - 2;
char *p = my_strndup(endw + 1, i);
if (conv->parse_args) {
i = conv->parse_args(p, &conv_expr->arg_p, &conv_expr->arg_i);
free(p);
if (!i)
goto out_error;
} else {
conv_expr->arg_i = i;
conv_expr->arg_p = p;
}
}
}
return expr;
out_error:
/* TODO: prune_pattern_expr(expr); */
return NULL;
}
/*
* Process a fetch + format conversion of defined by the pattern expression <expr>
* on request or response considering the <dir> parameter.
* Returns a pointer on a typed pattern structure containing the result or NULL if
* pattern 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 pattern structure.
*/
struct pattern *pattern_process(struct proxy *px, struct session *l4, void *l7, int dir,
struct pattern_expr *expr, struct pattern *p)
{
struct pattern_conv_expr *conv_expr;
if (p == NULL)
p = &spattern;
if (!expr->fetch->process(px, l4, l7, dir, expr->arg, expr->arg_len, &p->data))
return NULL;
p->type = expr->fetch->out_type;
list_for_each_entry(conv_expr, &expr->conv_exprs, list) {
if (!pattern_casts[p->type][conv_expr->conv->in_type](&p->data))
return NULL;
p->type = conv_expr->conv->in_type;
if (!conv_expr->conv->process(conv_expr->arg_p, conv_expr->arg_i, &p->data))
return NULL;
p->type = conv_expr->conv->out_type;
}
return p;
}
/*
* Process a fetch + format conversion of defined by the pattern expression <expr>
* on request or response considering the <dir> parameter.
* Returns a pointer on a static tablekey structure of type <table_type> of
* the converted result.
*/
struct stktable_key *pattern_process_key(struct proxy *px, struct session *l4, void *l7, int dir,
struct pattern_expr *expr, unsigned long table_type)
{
struct pattern *ptrn;
ptrn = pattern_process(px, l4, l7, dir, expr, NULL);
if (!ptrn)
return NULL;
stable_key.key_len = (size_t)-1;
stable_key.key = pattern_keys[ptrn->type][table_type](&ptrn->data, &stable_key.data, &stable_key.key_len);
if (!stable_key.key)
return NULL;
return &stable_key;
}
/*
* Returns 1 if pattern expression <expr> result cannot be converted to table key of
* type <table_type> .
*
* Used in configuration check
*/
int pattern_notusable_key(struct pattern_expr *expr, unsigned long table_type)
{
if (table_type >= STKTABLE_TYPES)
return 1;
if (LIST_ISEMPTY(&expr->conv_exprs)) {
if (!pattern_keys[expr->fetch->out_type][table_type])
return 1;
} else {
struct pattern_conv_expr *conv_expr;
conv_expr = LIST_PREV(&expr->conv_exprs, typeof(conv_expr), list);
if (!pattern_keys[conv_expr->conv->out_type][table_type])
return 1;
}
return 0;
}
/* Converts an argument string to an IPv4 mask stored in network byte order in
* arg_i. Returns non-zero in case of success, 0 on error.
*/
static int pattern_conv_arg_to_ipmask(const char *arg_str, void **arg_p, int *arg_i)
{
struct in_addr mask;
if (!str2mask(arg_str, &mask))
return 0;
*arg_i = mask.s_addr;
return 1;
}
/*****************************************************************/
/* Pattern format convert functions */
/*****************************************************************/
static int pattern_conv_str2lower(const void *arg_p, int arg_i, union pattern_data *data)
{
int i;
for (i = 0; i < data->str.len; i++) {
if ((data->str.str[i] >= 'A') && (data->str.str[i] <= 'Z'))
data->str.str[i] += 'a' - 'A';
}
return 1;
}
static int pattern_conv_str2upper(const void *arg_p, int arg_i, union pattern_data *data)
{
int i;
for (i = 0; i < data->str.len; i++) {
if ((data->str.str[i] >= 'a') && (data->str.str[i] <= 'z'))
data->str.str[i] += 'A' - 'a';
}
return 1;
}
/* takes the netmask in arg_i */
static int pattern_conv_ipmask(const void *arg_p, int arg_i, union pattern_data *data)
{
data->ip.s_addr &= arg_i;
return 1;
}
/* Note: must not be declared <const> as its list will be overwritten */
static struct pattern_conv_kw_list pattern_conv_kws = {{ },{
{ "upper", pattern_conv_str2upper, PATTERN_TYPE_STRING, PATTERN_TYPE_STRING },
{ "lower", pattern_conv_str2lower, PATTERN_TYPE_STRING, PATTERN_TYPE_STRING },
{ "ipmask", pattern_conv_ipmask, PATTERN_TYPE_IP, PATTERN_TYPE_IP, pattern_conv_arg_to_ipmask },
{ NULL, NULL, 0, 0 },
}};
__attribute__((constructor))
static void __pattern_init(void)
{
/* register pattern format convert keywords */
pattern_register_convs(&pattern_conv_kws);
}