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/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "private-lib-core.h"
static const unsigned char lextable_h1[] = {
#include "lextable.h"
};
#define FAIL_CHAR 0x08
#if defined(LWS_WITH_CUSTOM_HEADERS)
#define UHO_NLEN 0
#define UHO_VLEN 2
#define UHO_LL 4
#define UHO_NAME 8
#endif
static struct allocated_headers *
_lws_create_ah(struct lws_context_per_thread *pt, ah_data_idx_t data_size)
{
struct allocated_headers *ah = lws_zalloc(sizeof(*ah), "ah struct");
if (!ah)
return NULL;
ah->data = lws_malloc(data_size, "ah data");
if (!ah->data) {
lws_free(ah);
return NULL;
}
ah->next = pt->http.ah_list;
pt->http.ah_list = ah;
ah->data_length = data_size;
pt->http.ah_pool_length++;
lwsl_info("%s: created ah %p (size %d): pool length %u\n", __func__,
ah, (int)data_size, (unsigned int)pt->http.ah_pool_length);
return ah;
}
int
_lws_destroy_ah(struct lws_context_per_thread *pt, struct allocated_headers *ah)
{
lws_start_foreach_llp(struct allocated_headers **, a, pt->http.ah_list) {
if ((*a) == ah) {
*a = ah->next;
pt->http.ah_pool_length--;
lwsl_info("%s: freed ah %p : pool length %u\n",
__func__, ah,
(unsigned int)pt->http.ah_pool_length);
if (ah->data)
lws_free(ah->data);
lws_free(ah);
return 0;
}
} lws_end_foreach_llp(a, next);
return 1;
}
void
_lws_header_table_reset(struct allocated_headers *ah)
{
/* init the ah to reflect no headers or data have appeared yet */
memset(ah->frag_index, 0, sizeof(ah->frag_index));
memset(ah->frags, 0, sizeof(ah->frags));
ah->nfrag = 0;
ah->pos = 0;
ah->http_response = 0;
ah->parser_state = WSI_TOKEN_NAME_PART;
ah->lextable_pos = 0;
#if defined(LWS_WITH_CUSTOM_HEADERS)
ah->unk_pos = 0;
ah->unk_ll_head = 0;
ah->unk_ll_tail = 0;
#endif
}
// doesn't scrub the ah rxbuffer by default, parent must do if needed
void
__lws_header_table_reset(struct lws *wsi, int autoservice)
{
struct allocated_headers *ah = wsi->http.ah;
struct lws_context_per_thread *pt;
struct lws_pollfd *pfd;
/* if we have the idea we're resetting 'our' ah, must be bound to one */
assert(ah);
/* ah also concurs with ownership */
assert(ah->wsi == wsi);
_lws_header_table_reset(ah);
/* since we will restart the ah, our new headers are not completed */
wsi->hdr_parsing_completed = 0;
/* while we hold the ah, keep a timeout on the wsi */
__lws_set_timeout(wsi, PENDING_TIMEOUT_HOLDING_AH,
wsi->vhost->timeout_secs_ah_idle);
time(&ah->assigned);
if (wsi->position_in_fds_table != LWS_NO_FDS_POS &&
lws_buflist_next_segment_len(&wsi->buflist, NULL) &&
autoservice) {
lwsl_debug("%s: service on readbuf ah\n", __func__);
pt = &wsi->context->pt[(int)wsi->tsi];
/*
* Unlike a normal connect, we have the headers already
* (or the first part of them anyway)
*/
pfd = &pt->fds[wsi->position_in_fds_table];
pfd->revents |= LWS_POLLIN;
lwsl_err("%s: calling service\n", __func__);
lws_service_fd_tsi(wsi->context, pfd, wsi->tsi);
}
}
void
lws_header_table_reset(struct lws *wsi, int autoservice)
{
struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
lws_pt_lock(pt, __func__);
__lws_header_table_reset(wsi, autoservice);
lws_pt_unlock(pt);
}
static void
_lws_header_ensure_we_are_on_waiting_list(struct lws *wsi)
{
struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
struct lws_pollargs pa;
struct lws **pwsi = &pt->http.ah_wait_list;
while (*pwsi) {
if (*pwsi == wsi)
return;
pwsi = &(*pwsi)->http.ah_wait_list;
}
lwsl_info("%s: wsi: %p\n", __func__, wsi);
wsi->http.ah_wait_list = pt->http.ah_wait_list;
pt->http.ah_wait_list = wsi;
pt->http.ah_wait_list_length++;
/* we cannot accept input then */
_lws_change_pollfd(wsi, LWS_POLLIN, 0, &pa);
}
static int
__lws_remove_from_ah_waiting_list(struct lws *wsi)
{
struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
struct lws **pwsi =&pt->http.ah_wait_list;
while (*pwsi) {
if (*pwsi == wsi) {
lwsl_info("%s: wsi %p\n", __func__, wsi);
/* point prev guy to our next */
*pwsi = wsi->http.ah_wait_list;
/* we shouldn't point anywhere now */
wsi->http.ah_wait_list = NULL;
pt->http.ah_wait_list_length--;
return 1;
}
pwsi = &(*pwsi)->http.ah_wait_list;
}
return 0;
}
int LWS_WARN_UNUSED_RESULT
lws_header_table_attach(struct lws *wsi, int autoservice)
{
struct lws_context *context = wsi->context;
struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
struct lws_pollargs pa;
int n;
#if defined(LWS_ROLE_MQTT) && defined(LWS_WITH_CLIENT)
if (lwsi_role_mqtt(wsi))
goto connect_via_info2;
#endif
lwsl_info("%s: wsi %p: ah %p (tsi %d, count = %d) in\n", __func__,
(void *)wsi, (void *)wsi->http.ah, wsi->tsi,
pt->http.ah_count_in_use);
if (!lwsi_role_http(wsi)) {
lwsl_err("%s: bad role %s\n", __func__, wsi->role_ops->name);
assert(0);
return -1;
}
lws_pt_lock(pt, __func__);
/* if we are already bound to one, just clear it down */
if (wsi->http.ah) {
lwsl_info("%s: cleardown\n", __func__);
goto reset;
}
n = pt->http.ah_count_in_use == context->max_http_header_pool;
#if defined(LWS_WITH_PEER_LIMITS)
if (!n) {
n = lws_peer_confirm_ah_attach_ok(context, wsi->peer);
if (n)
lws_stats_bump(pt, LWSSTATS_C_PEER_LIMIT_AH_DENIED, 1);
}
#endif
if (n) {
/*
* Pool is either all busy, or we don't want to give this
* particular guy an ah right now...
*
* Make sure we are on the waiting list, and return that we
* weren't able to provide the ah
*/
_lws_header_ensure_we_are_on_waiting_list(wsi);
goto bail;
}
__lws_remove_from_ah_waiting_list(wsi);
wsi->http.ah = _lws_create_ah(pt, context->max_http_header_data);
if (!wsi->http.ah) { /* we could not create an ah */
_lws_header_ensure_we_are_on_waiting_list(wsi);
goto bail;
}
wsi->http.ah->in_use = 1;
wsi->http.ah->wsi = wsi; /* mark our owner */
pt->http.ah_count_in_use++;
#if defined(LWS_WITH_PEER_LIMITS) && (defined(LWS_ROLE_H1) || \
defined(LWS_ROLE_H2))
lws_context_lock(context, "ah attach"); /* <========================= */
if (wsi->peer)
wsi->peer->http.count_ah++;
lws_context_unlock(context); /* ====================================> */
#endif
_lws_change_pollfd(wsi, 0, LWS_POLLIN, &pa);
lwsl_info("%s: did attach wsi %p: ah %p: count %d (on exit)\n", __func__,
(void *)wsi, (void *)wsi->http.ah, pt->http.ah_count_in_use);
reset:
__lws_header_table_reset(wsi, autoservice);
lws_pt_unlock(pt);
#if defined(LWS_WITH_CLIENT)
#if defined(LWS_ROLE_MQTT)
connect_via_info2:
#endif
if (lwsi_role_client(wsi) && lwsi_state(wsi) == LRS_UNCONNECTED)
if (!lws_http_client_connect_via_info2(wsi))
/* our client connect has failed, the wsi
* has been closed
*/
return -1;
#endif
return 0;
bail:
lws_pt_unlock(pt);
return 1;
}
int __lws_header_table_detach(struct lws *wsi, int autoservice)
{
struct lws_context *context = wsi->context;
struct allocated_headers *ah = wsi->http.ah;
struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
struct lws_pollargs pa;
struct lws **pwsi, **pwsi_eligible;
time_t now;
__lws_remove_from_ah_waiting_list(wsi);
if (!ah)
return 0;
lwsl_info("%s: wsi %p: ah %p (tsi=%d, count = %d)\n", __func__,
(void *)wsi, (void *)ah, wsi->tsi,
pt->http.ah_count_in_use);
/* we did have an ah attached */
time(&now);
if (ah->assigned && now - ah->assigned > 3) {
/*
* we're detaching the ah, but it was held an
* unreasonably long time
*/
lwsl_debug("%s: wsi %p: ah held %ds, role/state 0x%lx 0x%x,"
"\n", __func__, wsi, (int)(now - ah->assigned),
(unsigned long)lwsi_role(wsi), lwsi_state(wsi));
}
ah->assigned = 0;
/* if we think we're detaching one, there should be one in use */
assert(pt->http.ah_count_in_use > 0);
/* and this specific one should have been in use */
assert(ah->in_use);
memset(&wsi->http.ah, 0, sizeof(wsi->http.ah));
#if defined(LWS_WITH_PEER_LIMITS)
if (ah->wsi)
lws_peer_track_ah_detach(context, wsi->peer);
#endif
ah->wsi = NULL; /* no owner */
wsi->http.ah = NULL;
pwsi = &pt->http.ah_wait_list;
/* oh there is nobody on the waiting list... leave the ah unattached */
if (!*pwsi)
goto nobody_usable_waiting;
/*
* at least one wsi on the same tsi is waiting, give it to oldest guy
* who is allowed to take it (if any)
*/
lwsl_info("pt wait list %p\n", *pwsi);
wsi = NULL;
pwsi_eligible = NULL;
while (*pwsi) {
#if defined(LWS_WITH_PEER_LIMITS)
/* are we willing to give this guy an ah? */
if (!lws_peer_confirm_ah_attach_ok(context, (*pwsi)->peer))
#endif
{
wsi = *pwsi;
pwsi_eligible = pwsi;
}
#if defined(LWS_WITH_PEER_LIMITS)
else
if (!(*pwsi)->http.ah_wait_list)
lws_stats_bump(pt,
LWSSTATS_C_PEER_LIMIT_AH_DENIED, 1);
#endif
pwsi = &(*pwsi)->http.ah_wait_list;
}
if (!wsi) /* everybody waiting already has too many ah... */
goto nobody_usable_waiting;
lwsl_info("%s: transferring ah to last eligible wsi in wait list "
"%p (wsistate 0x%lx)\n", __func__, wsi,
(unsigned long)wsi->wsistate);
wsi->http.ah = ah;
ah->wsi = wsi; /* new owner */
__lws_header_table_reset(wsi, autoservice);
#if defined(LWS_WITH_PEER_LIMITS) && (defined(LWS_ROLE_H1) || \
defined(LWS_ROLE_H2))
lws_context_lock(context, "ah detach"); /* <========================= */
if (wsi->peer)
wsi->peer->http.count_ah++;
lws_context_unlock(context); /* ====================================> */
#endif
/* clients acquire the ah and then insert themselves in fds table... */
if (wsi->position_in_fds_table != LWS_NO_FDS_POS) {
lwsl_info("%s: Enabling %p POLLIN\n", __func__, wsi);
/* he has been stuck waiting for an ah, but now his wait is
* over, let him progress */
_lws_change_pollfd(wsi, 0, LWS_POLLIN, &pa);
}
/* point prev guy to next guy in list instead */
*pwsi_eligible = wsi->http.ah_wait_list;
/* the guy who got one is out of the list */
wsi->http.ah_wait_list = NULL;
pt->http.ah_wait_list_length--;
#if defined(LWS_WITH_CLIENT)
if (lwsi_role_client(wsi) && lwsi_state(wsi) == LRS_UNCONNECTED) {
lws_pt_unlock(pt);
if (!lws_http_client_connect_via_info2(wsi)) {
/* our client connect has failed, the wsi
* has been closed
*/
return -1;
}
return 0;
}
#endif
assert(!!pt->http.ah_wait_list_length ==
!!(lws_intptr_t)pt->http.ah_wait_list);
bail:
lwsl_info("%s: wsi %p: ah %p (tsi=%d, count = %d)\n", __func__,
(void *)wsi, (void *)ah, pt->tid, pt->http.ah_count_in_use);
return 0;
nobody_usable_waiting:
lwsl_info("%s: nobody usable waiting\n", __func__);
_lws_destroy_ah(pt, ah);
pt->http.ah_count_in_use--;
goto bail;
}
int lws_header_table_detach(struct lws *wsi, int autoservice)
{
struct lws_context *context = wsi->context;
struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
int n;
lws_pt_lock(pt, __func__);
n = __lws_header_table_detach(wsi, autoservice);
lws_pt_unlock(pt);
return n;
}
int
lws_hdr_fragment_length(struct lws *wsi, enum lws_token_indexes h, int frag_idx)
{
int n;
if (!wsi->http.ah)
return 0;
n = wsi->http.ah->frag_index[h];
if (!n)
return 0;
do {
if (!frag_idx)
return wsi->http.ah->frags[n].len;
n = wsi->http.ah->frags[n].nfrag;
} while (frag_idx-- && n);
return 0;
}
int lws_hdr_total_length(struct lws *wsi, enum lws_token_indexes h)
{
int n;
int len = 0;
if (!wsi->http.ah)
return 0;
n = wsi->http.ah->frag_index[h];
if (!n)
return 0;
do {
len += wsi->http.ah->frags[n].len;
n = wsi->http.ah->frags[n].nfrag;
if (n && h != WSI_TOKEN_HTTP_COOKIE)
++len;
} while (n);
return len;
}
int lws_hdr_copy_fragment(struct lws *wsi, char *dst, int len,
enum lws_token_indexes h, int frag_idx)
{
int n = 0;
int f;
if (!wsi->http.ah)
return -1;
f = wsi->http.ah->frag_index[h];
if (!f)
return -1;
while (n < frag_idx) {
f = wsi->http.ah->frags[f].nfrag;
if (!f)
return -1;
n++;
}
if (wsi->http.ah->frags[f].len >= len)
return -1;
memcpy(dst, wsi->http.ah->data + wsi->http.ah->frags[f].offset,
wsi->http.ah->frags[f].len);
dst[wsi->http.ah->frags[f].len] = '\0';
return wsi->http.ah->frags[f].len;
}
int lws_hdr_copy(struct lws *wsi, char *dst, int len,
enum lws_token_indexes h)
{
int toklen = lws_hdr_total_length(wsi, h);
int n;
int comma;
*dst = '\0';
if (!toklen)
return 0;
if (toklen >= len)
return -1;
if (!wsi->http.ah)
return -1;
n = wsi->http.ah->frag_index[h];
if (!n)
return 0;
do {
comma = (wsi->http.ah->frags[n].nfrag &&
h != WSI_TOKEN_HTTP_COOKIE) ? 1 : 0;
if (wsi->http.ah->frags[n].len + comma >= len)
return -1;
strncpy(dst, &wsi->http.ah->data[wsi->http.ah->frags[n].offset],
wsi->http.ah->frags[n].len);
dst += wsi->http.ah->frags[n].len;
len -= wsi->http.ah->frags[n].len;
n = wsi->http.ah->frags[n].nfrag;
if (comma)
*dst++ = ',';
} while (n);
*dst = '\0';
return toklen;
}
#if defined(LWS_WITH_CUSTOM_HEADERS)
int
lws_hdr_custom_length(struct lws *wsi, const char *name, int nlen)
{
ah_data_idx_t ll;
if (!wsi->http.ah || wsi->mux_substream)
return -1;
ll = wsi->http.ah->unk_ll_head;
while (ll) {
if (ll >= wsi->http.ah->data_length)
return -1;
if (nlen == lws_ser_ru16be(
(uint8_t *)&wsi->http.ah->data[ll + UHO_NLEN]) &&
!strncmp(name, &wsi->http.ah->data[ll + UHO_NAME], nlen))
return lws_ser_ru16be(
(uint8_t *)&wsi->http.ah->data[ll + UHO_VLEN]);
ll = lws_ser_ru32be((uint8_t *)&wsi->http.ah->data[ll + UHO_LL]);
}
return -1;
}
int
lws_hdr_custom_copy(struct lws *wsi, char *dst, int len, const char *name,
int nlen)
{
ah_data_idx_t ll;
int n;
if (!wsi->http.ah || wsi->mux_substream)
return -1;
*dst = '\0';
ll = wsi->http.ah->unk_ll_head;
while (ll) {
if (ll >= wsi->http.ah->data_length)
return -1;
if (nlen == lws_ser_ru16be(
(uint8_t *)&wsi->http.ah->data[ll + UHO_NLEN]) &&
!strncmp(name, &wsi->http.ah->data[ll + UHO_NAME], nlen)) {
n = lws_ser_ru16be(
(uint8_t *)&wsi->http.ah->data[ll + UHO_VLEN]);
if (n + 1 > len)
return -1;
strncpy(dst, &wsi->http.ah->data[ll + UHO_NAME + nlen], n);
dst[n] = '\0';
return n;
}
ll = lws_ser_ru32be((uint8_t *)&wsi->http.ah->data[ll + UHO_LL]);
}
return -1;
}
#endif
char *lws_hdr_simple_ptr(struct lws *wsi, enum lws_token_indexes h)
{
int n;
if (!wsi->http.ah)
return NULL;
n = wsi->http.ah->frag_index[h];
if (!n)
return NULL;
return wsi->http.ah->data + wsi->http.ah->frags[n].offset;
}
static int LWS_WARN_UNUSED_RESULT
lws_pos_in_bounds(struct lws *wsi)
{
if (!wsi->http.ah)
return -1;
if (wsi->http.ah->pos <
(unsigned int)wsi->context->max_http_header_data)
return 0;
if ((int)wsi->http.ah->pos >= wsi->context->max_http_header_data - 1) {
lwsl_err("Ran out of header data space\n");
return 1;
}
/*
* with these tests everywhere, it should never be able to exceed
* the limit, only meet it
*/
lwsl_err("%s: pos %ld, limit %ld\n", __func__,
(unsigned long)wsi->http.ah->pos,
(unsigned long)wsi->context->max_http_header_data);
assert(0);
return 1;
}
int LWS_WARN_UNUSED_RESULT
lws_hdr_simple_create(struct lws *wsi, enum lws_token_indexes h, const char *s)
{
if (!*s) {
/*
* If we get an empty string, then remove any entry for the
* header
*/
wsi->http.ah->frag_index[h] = 0;
return 0;
}
wsi->http.ah->nfrag++;
if (wsi->http.ah->nfrag == LWS_ARRAY_SIZE(wsi->http.ah->frags)) {
lwsl_warn("More hdr frags than we can deal with, dropping\n");
return -1;
}
wsi->http.ah->frag_index[h] = wsi->http.ah->nfrag;
wsi->http.ah->frags[wsi->http.ah->nfrag].offset = wsi->http.ah->pos;
wsi->http.ah->frags[wsi->http.ah->nfrag].len = 0;
wsi->http.ah->frags[wsi->http.ah->nfrag].nfrag = 0;
do {
if (lws_pos_in_bounds(wsi))
return -1;
wsi->http.ah->data[wsi->http.ah->pos++] = *s;
if (*s)
wsi->http.ah->frags[wsi->http.ah->nfrag].len++;
} while (*s++);
return 0;
}
static int LWS_WARN_UNUSED_RESULT
issue_char(struct lws *wsi, unsigned char c)
{
unsigned short frag_len;
if (lws_pos_in_bounds(wsi))
return -1;
frag_len = wsi->http.ah->frags[wsi->http.ah->nfrag].len;
/*
* If we haven't hit the token limit, just copy the character into
* the header
*/
if (!wsi->http.ah->current_token_limit ||
frag_len < wsi->http.ah->current_token_limit) {
wsi->http.ah->data[wsi->http.ah->pos++] = c;
if (c)
wsi->http.ah->frags[wsi->http.ah->nfrag].len++;
return 0;
}
/* Insert a null character when we *hit* the limit: */
if (frag_len == wsi->http.ah->current_token_limit) {
if (lws_pos_in_bounds(wsi))
return -1;
wsi->http.ah->data[wsi->http.ah->pos++] = '\0';
lwsl_warn("header %li exceeds limit %ld\n",
(long)wsi->http.ah->parser_state,
(long)wsi->http.ah->current_token_limit);
}
return 1;
}
int
lws_parse_urldecode(struct lws *wsi, uint8_t *_c)
{
struct allocated_headers *ah = wsi->http.ah;
unsigned int enc = 0;
uint8_t c = *_c;
// lwsl_notice("ah->ups %d\n", ah->ups);
/*
* PRIORITY 1
* special URI processing... convert %xx
*/
switch (ah->ues) {
case URIES_IDLE:
if (c == '%') {
ah->ues = URIES_SEEN_PERCENT;
goto swallow;
}
break;
case URIES_SEEN_PERCENT:
if (char_to_hex(c) < 0)
/* illegal post-% char */
goto forbid;
ah->esc_stash = c;
ah->ues = URIES_SEEN_PERCENT_H1;
goto swallow;
case URIES_SEEN_PERCENT_H1:
if (char_to_hex(c) < 0)
/* illegal post-% char */
goto forbid;
*_c = (char_to_hex(ah->esc_stash) << 4) |
char_to_hex(c);
c = *_c;
enc = 1;
ah->ues = URIES_IDLE;
break;
}
/*
* PRIORITY 2
* special URI processing...
* convert /.. or /... or /../ etc to /
* convert /./ to /
* convert // or /// etc to /
* leave /.dir or whatever alone
*/
switch (ah->ups) {
case URIPS_IDLE:
if (!c)
return -1;
/* genuine delimiter */
if ((c == '&' || c == ';') && !enc) {
if (issue_char(wsi, '\0') < 0)
return -1;
/* link to next fragment */
ah->frags[ah->nfrag].nfrag = ah->nfrag + 1;
ah->nfrag++;
if (ah->nfrag >= LWS_ARRAY_SIZE(ah->frags))
goto excessive;
/* start next fragment after the & */
ah->post_literal_equal = 0;
ah->frags[ah->nfrag].offset = ++ah->pos;
ah->frags[ah->nfrag].len = 0;
ah->frags[ah->nfrag].nfrag = 0;
goto swallow;
}
/* uriencoded = in the name part, disallow */
if (c == '=' && enc &&
ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS] &&
!ah->post_literal_equal) {
c = '_';
*_c =c;
}
/* after the real =, we don't care how many = */
if (c == '=' && !enc)
ah->post_literal_equal = 1;
/* + to space */
if (c == '+' && !enc) {
c = ' ';
*_c = c;
}
/* issue the first / always */
if (c == '/' && !ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS])
ah->ups = URIPS_SEEN_SLASH;
break;
case URIPS_SEEN_SLASH:
/* swallow subsequent slashes */
if (c == '/')
goto swallow;
/* track and swallow the first . after / */
if (c == '.') {
ah->ups = URIPS_SEEN_SLASH_DOT;
goto swallow;
}
ah->ups = URIPS_IDLE;
break;
case URIPS_SEEN_SLASH_DOT:
/* swallow second . */
if (c == '.') {
ah->ups = URIPS_SEEN_SLASH_DOT_DOT;
goto swallow;
}
/* change /./ to / */
if (c == '/') {
ah->ups = URIPS_SEEN_SLASH;
goto swallow;
}
/* it was like /.dir ... regurgitate the . */
ah->ups = URIPS_IDLE;
if (issue_char(wsi, '.') < 0)
return -1;
break;
case URIPS_SEEN_SLASH_DOT_DOT:
/* /../ or /..[End of URI] --> backup to last / */
if (c == '/' || c == '?') {
/*
* back up one dir level if possible
* safe against header fragmentation because
* the method URI can only be in 1 fragment
*/
if (ah->frags[ah->nfrag].len > 2) {
ah->pos--;
ah->frags[ah->nfrag].len--;
do {
ah->pos--;
ah->frags[ah->nfrag].len--;
} while (ah->frags[ah->nfrag].len > 1 &&
ah->data[ah->pos] != '/');
}
ah->ups = URIPS_SEEN_SLASH;
if (ah->frags[ah->nfrag].len > 1)
break;
goto swallow;
}
/* /..[^/] ... regurgitate and allow */
if (issue_char(wsi, '.') < 0)
return -1;
if (issue_char(wsi, '.') < 0)
return -1;
ah->ups = URIPS_IDLE;
break;
}
if (c == '?' && !enc &&
!ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS]) { /* start of URI args */
if (ah->ues != URIES_IDLE)
goto forbid;
/* seal off uri header */
if (issue_char(wsi, '\0') < 0)
return -1;
/* move to using WSI_TOKEN_HTTP_URI_ARGS */
ah->nfrag++;
if (ah->nfrag >= LWS_ARRAY_SIZE(ah->frags))
goto excessive;
ah->frags[ah->nfrag].offset = ++ah->pos;
ah->frags[ah->nfrag].len = 0;
ah->frags[ah->nfrag].nfrag = 0;
ah->post_literal_equal = 0;
ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS] = ah->nfrag;
ah->ups = URIPS_IDLE;
goto swallow;
}
return LPUR_CONTINUE;
swallow:
return LPUR_SWALLOW;
forbid:
return LPUR_FORBID;
excessive:
return LPUR_EXCESSIVE;
}
static const unsigned char methods[] = {
WSI_TOKEN_GET_URI,
WSI_TOKEN_POST_URI,
#if defined(LWS_WITH_HTTP_UNCOMMON_HEADERS)
WSI_TOKEN_OPTIONS_URI,
WSI_TOKEN_PUT_URI,
WSI_TOKEN_PATCH_URI,
WSI_TOKEN_DELETE_URI,
#endif
WSI_TOKEN_CONNECT,
WSI_TOKEN_HEAD_URI,
};
/*
* possible returns:, -1 fail, 0 ok or 2, transition to raw
*/
lws_parser_return_t LWS_WARN_UNUSED_RESULT
lws_parse(struct lws *wsi, unsigned char *buf, int *len)
{
struct allocated_headers *ah = wsi->http.ah;
struct lws_context *context = wsi->context;
unsigned int n, m;
unsigned char c;
int r, pos;
assert(wsi->http.ah);
do {
(*len)--;
c = *buf++;
switch (ah->parser_state) {
#if defined(LWS_WITH_CUSTOM_HEADERS)
case WSI_TOKEN_UNKNOWN_VALUE_PART:
if (c == '\r')
break;
if (c == '\n') {
lws_ser_wu16be((uint8_t *)&ah->data[ah->unk_pos + 2],
ah->pos - ah->unk_value_pos);
ah->parser_state = WSI_TOKEN_NAME_PART;
ah->unk_pos = 0;
ah->lextable_pos = 0;
break;
}
/* trim leading whitespace */
if (ah->pos != ah->unk_value_pos ||
(c != ' ' && c != '\t')) {
if (lws_pos_in_bounds(wsi))
return LPR_FAIL;
ah->data[ah->pos++] = c;
}
pos = ah->lextable_pos;
break;
#endif
default:
lwsl_parser("WSI_TOK_(%d) '%c'\n", ah->parser_state, c);
/* collect into malloc'd buffers */
/* optional initial space swallow */
if (!ah->frags[ah->frag_index[ah->parser_state]].len &&
c == ' ')
break;
for (m = 0; m < LWS_ARRAY_SIZE(methods); m++)
if (ah->parser_state == methods[m])
break;
if (m == LWS_ARRAY_SIZE(methods))
/* it was not any of the methods */
goto check_eol;
/* special URI processing... end at space */
if (c == ' ') {
/* enforce starting with / */
if (!ah->frags[ah->nfrag].len)
if (issue_char(wsi, '/') < 0)
return LPR_FAIL;
if (ah->ups == URIPS_SEEN_SLASH_DOT_DOT) {
/*
* back up one dir level if possible
* safe against header fragmentation
* because the method URI can only be
* in 1 fragment
*/
if (ah->frags[ah->nfrag].len > 2) {
ah->pos--;
ah->frags[ah->nfrag].len--;
do {
ah->pos--;
ah->frags[ah->nfrag].len--;
} while (ah->frags[ah->nfrag].len > 1 &&
ah->data[ah->pos] != '/');
}
}
/* begin parsing HTTP version: */
if (issue_char(wsi, '\0') < 0)
return LPR_FAIL;
ah->parser_state = WSI_TOKEN_HTTP;
goto start_fragment;
}
r = lws_parse_urldecode(wsi, &c);
switch (r) {
case LPUR_CONTINUE:
break;
case LPUR_SWALLOW:
goto swallow;
case LPUR_FORBID:
goto forbid;
case LPUR_EXCESSIVE:
goto excessive;
default:
return LPR_FAIL;
}
check_eol:
/* bail at EOL */
if (ah->parser_state != WSI_TOKEN_CHALLENGE &&
c == '\x0d') {
if (ah->ues != URIES_IDLE)
goto forbid;
c = '\0';
ah->parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
lwsl_parser("*\n");
}
n = issue_char(wsi, c);
if ((int)n < 0)
return LPR_FAIL;
if (n > 0)
ah->parser_state = WSI_TOKEN_SKIPPING;
swallow:
/* per-protocol end of headers management */
if (ah->parser_state == WSI_TOKEN_CHALLENGE)
goto set_parsing_complete;
break;
/* collecting and checking a name part */
case WSI_TOKEN_NAME_PART:
lwsl_parser("WSI_TOKEN_NAME_PART '%c' 0x%02X "
"(role=0x%lx) "
"wsi->lextable_pos=%d\n", c, c,
(unsigned long)lwsi_role(wsi),
ah->lextable_pos);
if (c >= 'A' && c <= 'Z')
c += 'a' - 'A';
#if defined(LWS_WITH_CUSTOM_HEADERS)
/*
* ...in case it's an unknown header, speculatively
* store it as the name comes in. If we recognize it as
* a known header, we'll snip this.
*/
if (!wsi->mux_substream && !ah->unk_pos) {
ah->unk_pos = ah->pos;
/*
* Prepare new unknown header linked-list entry
*
* - 16-bit BE: name part length
* - 16-bit BE: value part length
* - 32-bit BE: data offset of next, or 0
*/
for (n = 0; n < 8; n++)
if (!lws_pos_in_bounds(wsi))
ah->data[ah->pos++] = 0;
}
#endif
if (lws_pos_in_bounds(wsi))
return LPR_FAIL;
ah->data[ah->pos++] = c;
pos = ah->lextable_pos;
#if defined(LWS_WITH_CUSTOM_HEADERS)
if (!wsi->mux_substream && pos < 0 && c == ':') {
#if defined(_DEBUG)
char dotstar[64];
int uhlen;
#endif
/*
* process unknown headers
*
* register us in the unknown hdr ll
*/
if (!ah->unk_ll_head)
ah->unk_ll_head = ah->unk_pos;
if (ah->unk_ll_tail)
lws_ser_wu32be(
(uint8_t *)&ah->data[ah->unk_ll_tail + UHO_LL],
ah->unk_pos);
ah->unk_ll_tail = ah->unk_pos;
#if defined(_DEBUG)
uhlen = ah->pos - (ah->unk_pos + UHO_NAME);
lws_strnncpy(dotstar,
&ah->data[ah->unk_pos + UHO_NAME],
uhlen, sizeof(dotstar));
lwsl_debug("%s: unk header %d '%s'\n",
__func__,
ah->pos - (ah->unk_pos + UHO_NAME),
dotstar);
#endif
/* set the unknown header name part length */
lws_ser_wu16be((uint8_t *)&ah->data[ah->unk_pos],
(ah->pos - ah->unk_pos) - UHO_NAME);
ah->unk_value_pos = ah->pos;
/*
* collect whatever's coming for the unknown header
* argument until the next CRLF
*/
ah->parser_state = WSI_TOKEN_UNKNOWN_VALUE_PART;
break;
}
#endif
if (pos < 0)
break;
while (1) {
if (lextable_h1[pos] & (1 << 7)) {
/* 1-byte, fail on mismatch */
if ((lextable_h1[pos] & 0x7f) != c) {
nope:
ah->lextable_pos = -1;
break;
}
/* fall thru */
pos++;
if (lextable_h1[pos] == FAIL_CHAR)
goto nope;
ah->lextable_pos = pos;
break;
}
if (lextable_h1[pos] == FAIL_CHAR)
goto nope;
/* b7 = 0, end or 3-byte */
if (lextable_h1[pos] < FAIL_CHAR) {
#if defined(LWS_WITH_CUSTOM_HEADERS)
if (!wsi->mux_substream) {
/*
* We hit a terminal marker, so
* we recognized this header...
* drop the speculative name
* part storage
*/
ah->pos = ah->unk_pos;
ah->unk_pos = 0;
}
#endif
ah->lextable_pos = pos;
break;
}
if (lextable_h1[pos] == c) { /* goto */
ah->lextable_pos = pos +
(lextable_h1[pos + 1]) +
(lextable_h1[pos + 2] << 8);
break;
}
/* fall thru goto */
pos += 3;
/* continue */
}
/*
* If it's h1, server needs to be on the look out for
* unknown methods...
*/
if (ah->lextable_pos < 0 && lwsi_role_h1(wsi) &&
lwsi_role_server(wsi)) {
/*
* this is not a header we know about... did
* we get a valid method (GET, POST etc)
* already, or is this the bogus method?
*/
for (m = 0; m < LWS_ARRAY_SIZE(methods); m++)
if (ah->frag_index[methods[m]]) {
/*
* already had the method
*/
#if !defined(LWS_WITH_CUSTOM_HEADERS)
ah->parser_state = WSI_TOKEN_SKIPPING;
#endif
if (wsi->mux_substream)
ah->parser_state = WSI_TOKEN_SKIPPING;
break;
}
if (m != LWS_ARRAY_SIZE(methods)) {
#if defined(LWS_WITH_CUSTOM_HEADERS)
/*
* We have the method, this is just an
* unknown header then
*/
if (!wsi->mux_substream)
goto unknown_hdr;
else
break;
#else
break;
#endif
}
/*
* ...it's an unknown http method from a client
* in fact, it cannot be valid http.
*
* Are we set up to transition to another role
* in these cases?
*/
if (lws_check_opt(wsi->vhost->options,
LWS_SERVER_OPTION_FALLBACK_TO_APPLY_LISTEN_ACCEPT_CONFIG)) {
lwsl_notice("%s: http fail fallback\n",
__func__);
/* transition to other role */
return LPR_DO_FALLBACK;
}
lwsl_info("Unknown method - dropping\n");
goto forbid;
}
if (ah->lextable_pos < 0) {
#if defined(LWS_WITH_CUSTOM_HEADERS)
if (!wsi->mux_substream)
goto unknown_hdr;
#endif
/*
* ...otherwise for a client, let him ignore
* unknown headers coming from the server
*/
ah->parser_state = WSI_TOKEN_SKIPPING;
break;
}
if (lextable_h1[ah->lextable_pos] < FAIL_CHAR) {
/* terminal state */
n = ((unsigned int)lextable_h1[ah->lextable_pos] << 8) |
lextable_h1[ah->lextable_pos + 1];
lwsl_parser("known hdr %d\n", n);
for (m = 0; m < LWS_ARRAY_SIZE(methods); m++)
if (n == methods[m] &&
ah->frag_index[methods[m]]) {
lwsl_warn("Duplicated method\n");
return LPR_FAIL;
}
/*
* WSORIGIN is protocol equiv to ORIGIN,
* JWebSocket likes to send it, map to ORIGIN
*/
#if defined(LWS_ROLE_WS)
if (n == WSI_TOKEN_SWORIGIN)
n = WSI_TOKEN_ORIGIN;
#endif
ah->parser_state = (enum lws_token_indexes)
(WSI_TOKEN_GET_URI + n);
ah->ups = URIPS_IDLE;
if (context->token_limits)
ah->current_token_limit = context->
token_limits->token_limit[
ah->parser_state];
else
ah->current_token_limit =
wsi->context->max_http_header_data;
if (ah->parser_state == WSI_TOKEN_CHALLENGE)
goto set_parsing_complete;
goto start_fragment;
}
break;
#if defined(LWS_WITH_CUSTOM_HEADERS)
unknown_hdr:
//ah->parser_state = WSI_TOKEN_SKIPPING;
//break;
if (!wsi->mux_substream)
break;
#endif
start_fragment:
ah->nfrag++;
excessive:
if (ah->nfrag == LWS_ARRAY_SIZE(ah->frags)) {
lwsl_warn("More hdr frags than we can deal with\n");
return LPR_FAIL;
}
ah->frags[ah->nfrag].offset = ah->pos;
ah->frags[ah->nfrag].len = 0;
ah->frags[ah->nfrag].nfrag = 0;
ah->frags[ah->nfrag].flags = 2;
n = ah->frag_index[ah->parser_state];
if (!n) { /* first fragment */
ah->frag_index[ah->parser_state] = ah->nfrag;
ah->hdr_token_idx = ah->parser_state;
break;
}
/* continuation */
while (ah->frags[n].nfrag)
n = ah->frags[n].nfrag;
ah->frags[n].nfrag = ah->nfrag;
if (issue_char(wsi, ' ') < 0)
return LPR_FAIL;
break;
/* skipping arg part of a name we didn't recognize */
case WSI_TOKEN_SKIPPING:
lwsl_parser("WSI_TOKEN_SKIPPING '%c'\n", c);
if (c == '\x0d')
ah->parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
break;
case WSI_TOKEN_SKIPPING_SAW_CR:
lwsl_parser("WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c);
if (ah->ues != URIES_IDLE)
goto forbid;
if (c == '\x0a') {
ah->parser_state = WSI_TOKEN_NAME_PART;
#if defined(LWS_WITH_CUSTOM_HEADERS)
ah->unk_pos = 0;
#endif
ah->lextable_pos = 0;
} else
ah->parser_state = WSI_TOKEN_SKIPPING;
break;
/* we're done, ignore anything else */
case WSI_PARSING_COMPLETE:
lwsl_parser("WSI_PARSING_COMPLETE '%c'\n", c);
break;
}
} while (*len);
return LPR_OK;
set_parsing_complete:
if (ah->ues != URIES_IDLE)
goto forbid;
if (lws_hdr_total_length(wsi, WSI_TOKEN_UPGRADE)) {
#if defined(LWS_ROLE_WS)
if (lws_hdr_total_length(wsi, WSI_TOKEN_VERSION))
wsi->rx_frame_type = /* temp for ws version index */
atoi(lws_hdr_simple_ptr(wsi, WSI_TOKEN_VERSION));
lwsl_parser("v%02d hdrs done\n", wsi->rx_frame_type);
#endif
}
ah->parser_state = WSI_PARSING_COMPLETE;
wsi->hdr_parsing_completed = 1;
return LPR_OK;
forbid:
lwsl_info(" forbidding on uri sanitation\n");
#if defined(LWS_WITH_SERVER)
lws_return_http_status(wsi, HTTP_STATUS_FORBIDDEN, NULL);
#endif
return LPR_FORBIDDEN;
}