diff options
Diffstat (limited to 'thirdparty/libwebsockets/roles/http/server/parsers.c')
| -rw-r--r-- | thirdparty/libwebsockets/roles/http/server/parsers.c | 1139 |
1 files changed, 1139 insertions, 0 deletions
diff --git a/thirdparty/libwebsockets/roles/http/server/parsers.c b/thirdparty/libwebsockets/roles/http/server/parsers.c new file mode 100644 index 0000000000..cb022e362b --- /dev/null +++ b/thirdparty/libwebsockets/roles/http/server/parsers.c @@ -0,0 +1,1139 @@ +/* + * libwebsockets - small server side websockets and web server implementation + * + * Copyright (C) 2010-2018 Andy Green <andy@warmcat.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation: + * version 2.1 of the License. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + * MA 02110-1301 USA + */ + +#include "core/private.h" + +static const unsigned char lextable[] = { + #include "../lextable.h" +}; + +#define FAIL_CHAR 0x08 + +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 %d\n", __func__, + ah, (int)data_size, 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 %d\n", + __func__, ah, 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; +} + +// 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; + + 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); + + 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_atomic_bump(wsi->context, 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); /* <====================================== */ + 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); + +#ifndef LWS_NO_CLIENT + if (lwsi_role_client(wsi) && lwsi_state(wsi) == LRS_UNCONNECTED) + if (!lws_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%x 0x%x," + "\n", __func__, wsi, (int)(now - ah->assigned), + 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 */ + + 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_atomic_bump(context, 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%x)\n", __func__, wsi, 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); /* <====================================== */ + 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--; + +#ifndef LWS_NO_CLIENT + if (lwsi_role_client(wsi) && lwsi_state(wsi) == LRS_UNCONNECTED) { + lws_pt_unlock(pt); + + if (!lws_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; +} + +LWS_VISIBLE 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; +} + +LWS_VISIBLE 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; + } while (n); + + return len; +} + +LWS_VISIBLE 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; +} + +LWS_VISIBLE 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; + + if (toklen >= len) + return -1; + + if (!wsi->http.ah) + return -1; + + n = wsi->http.ah->frag_index[h]; + if (!n) + return 0; + + do { + if (wsi->http.ah->frags[n].len >= 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; + } while (n); + *dst = '\0'; + + return toklen; +} + +char *lws_hdr_simple_ptr(struct lws *wsi, enum lws_token_indexes h) +{ + int n; + + 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->pos < + (unsigned int)wsi->context->max_http_header_data) + return 0; + + if ((int)wsi->http.ah->pos == wsi->context->max_http_header_data) { + 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 %d, limit %d\n", __func__, wsi->http.ah->pos, + 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) +{ + wsi->http.ah->nfrag++; + if (wsi->http.ah->nfrag == 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 (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 %i exceeds limit %d\n", + wsi->http.ah->parser_state, + 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, c) < 0) + return -1; + /* swallow the terminator */ + ah->frags[ah->nfrag].len--; + /* link to next fragment */ + ah->frags[ah->nfrag].nfrag = ah->nfrag + 1; + ah->nfrag++; + if (ah->nfrag >= 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 >= 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, + WSI_TOKEN_OPTIONS_URI, + WSI_TOKEN_PUT_URI, + WSI_TOKEN_PATCH_URI, + WSI_TOKEN_DELETE_URI, + WSI_TOKEN_CONNECT, + WSI_TOKEN_HEAD_URI, +}; + +/* + * possible returns:, -1 fail, 0 ok or 2, transition to raw + */ + +int 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) { + 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 < ARRAY_SIZE(methods); m++) + if (ah->parser_state == methods[m]) + break; + if (m == 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 -1; + + 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 -1; + 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 -1; + } +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 -1; + 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%x) " + "wsi->lextable_pos=%d\n", c, c, lwsi_role(wsi), + ah->lextable_pos); + + if (c >= 'A' && c <= 'Z') + c += 'a' - 'A'; + + pos = ah->lextable_pos; + + while (1) { + if (lextable[pos] & (1 << 7)) { /* 1-byte, fail on mismatch */ + if ((lextable[pos] & 0x7f) != c) { +nope: + ah->lextable_pos = -1; + break; + } + /* fall thru */ + pos++; + if (lextable[pos] == FAIL_CHAR) + goto nope; + + ah->lextable_pos = pos; + break; + } + + if (lextable[pos] == FAIL_CHAR) + goto nope; + + /* b7 = 0, end or 3-byte */ + if (lextable[pos] < FAIL_CHAR) { /* terminal marker */ + ah->lextable_pos = pos; + break; + } + + if (lextable[pos] == c) { /* goto */ + ah->lextable_pos = pos + (lextable[pos + 1]) + + (lextable[pos + 2] << 8); + break; + } + + /* fall thru goto */ + pos += 3; + /* continue */ + } + + /* + * If it's h1, server needs to 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 */ + for (m = 0; m < ARRAY_SIZE(methods); m++) + if (ah->frag_index[methods[m]]) { + /* + * already had the method, no idea what + * this crap from the client is, ignore + */ + ah->parser_state = WSI_TOKEN_SKIPPING; + break; + } + /* + * hm it's an unknown http method from a client in fact, + * it cannot be valid http + */ + if (m == ARRAY_SIZE(methods)) { + /* + * are we set up to accept raw in these cases? + */ + if (lws_check_opt(wsi->vhost->options, + LWS_SERVER_OPTION_FALLBACK_TO_RAW)) + return 2; /* transition to raw */ + + lwsl_info("Unknown method - dropping\n"); + goto forbid; + } + break; + } + /* + * ...otherwise for a client, let him ignore unknown headers + * coming from the server + */ + if (ah->lextable_pos < 0) { + ah->parser_state = WSI_TOKEN_SKIPPING; + break; + } + + if (lextable[ah->lextable_pos] < FAIL_CHAR) { + /* terminal state */ + + n = ((unsigned int)lextable[ah->lextable_pos] << 8) | + lextable[ah->lextable_pos + 1]; + + lwsl_parser("known hdr %d\n", n); + for (m = 0; m < ARRAY_SIZE(methods); m++) + if (n == methods[m] && + ah->frag_index[methods[m]]) { + lwsl_warn("Duplicated method\n"); + return -1; + } + + /* + * WSORIGIN is protocol equiv to ORIGIN, + * JWebSocket likes to send it, map to ORIGIN + */ + if (n == WSI_TOKEN_SWORIGIN) + n = WSI_TOKEN_ORIGIN; + + 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; + +start_fragment: + ah->nfrag++; +excessive: + if (ah->nfrag == ARRAY_SIZE(ah->frags)) { + lwsl_warn("More hdr frags than we can deal with\n"); + return -1; + } + + 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 -1; + 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; + 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 0; + +set_parsing_complete: + if (ah->ues != URIES_IDLE) + goto forbid; + if (lws_hdr_total_length(wsi, WSI_TOKEN_UPGRADE)) { + 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); + } + ah->parser_state = WSI_PARSING_COMPLETE; + wsi->hdr_parsing_completed = 1; + + return 0; + +forbid: + lwsl_notice(" forbidding on uri sanitation\n"); + lws_return_http_status(wsi, HTTP_STATUS_FORBIDDEN, NULL); + + return -1; +} + |