Mercurial > hg > nginx
view src/http/modules/ngx_http_sub_filter_module.c @ 9203:0de20f43db25
Fixed request termination with AIO and subrequests (ticket #2555).
When a request was terminated due to an error via ngx_http_terminate_request()
while an AIO operation was running in a subrequest, various issues were
observed. This happened because ngx_http_request_finalizer() was only set
in the subrequest where ngx_http_terminate_request() was called, but not
in the subrequest where the AIO operation was running. After completion
of the AIO operation normal processing of the subrequest was resumed, leading
to issues.
In particular, in case of the upstream module, termination of the request
called upstream cleanup, which closed the upstream connection. Attempts to
further work with the upstream connection after AIO operation completion
resulted in segfaults in ngx_ssl_recv(), "readv() failed (9: Bad file
descriptor) while reading upstream" errors, or socket leaks.
In ticket #2555, issues were observed with the following configuration
with cache background update (with thread writing instrumented to
introduce a delay, when a client closes the connection during an update):
location = /background-and-aio-write {
proxy_pass ...
proxy_cache one;
proxy_cache_valid 200 1s;
proxy_cache_background_update on;
proxy_cache_use_stale updating;
aio threads;
aio_write on;
limit_rate 1000;
}
Similarly, the same issue can be seen with SSI, and can be caused by
errors in subrequests, such as in the following configuration
(where "/proxy" uses AIO, and "/sleep" returns 444 after some delay,
causing request termination):
location = /ssi-active-boom {
ssi on;
ssi_types *;
return 200 '
<!--#include virtual="/proxy" -->
<!--#include virtual="/sleep" -->
';
limit_rate 1000;
}
Or the same with both AIO operation and the error in non-active subrequests
(which needs slightly different handling, see below):
location = /ssi-non-active-boom {
ssi on;
ssi_types *;
return 200 '
<!--#include virtual="/static" -->
<!--#include virtual="/proxy" -->
<!--#include virtual="/sleep" -->
';
limit_rate 1000;
}
Similarly, issues can be observed with just static files. However,
with static files potential impact is limited due to timeout safeguards
in ngx_http_writer(), and the fact that c->error is set during request
termination.
In a simple configuration with an AIO operation in the active subrequest,
such as in the following configuration, the connection is closed right
after completion of the AIO operation anyway, since ngx_http_writer()
tries to write to the connection and fails due to c->error set:
location = /ssi-active-static-boom {
ssi on;
ssi_types *;
return 200 '
<!--#include virtual="/static-aio" -->
<!--#include virtual="/sleep" -->
';
limit_rate 1000;
}
In the following configuration, with an AIO operation in a non-active
subrequest, the connection is closed only after send_timeout expires:
location = /ssi-non-active-static-boom {
ssi on;
ssi_types *;
return 200 '
<!--#include virtual="/static" -->
<!--#include virtual="/static-aio" -->
<!--#include virtual="/sleep" -->
';
limit_rate 1000;
}
Fix is to introduce r->main->terminated flag, which is to be checked
by AIO event handlers when the r->main->blocked counter is decremented.
When the flag is set, handlers are expected to wake up the connection
instead of the subrequest (which might be already cleaned up).
Additionally, now ngx_http_request_finalizer() is always set in the
active subrequest, so waking up the connection properly finalizes the
request even if termination happened in a non-active subrequest.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 30 Jan 2024 03:20:05 +0300 |
parents | 201038680680 |
children |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_http_complex_value_t match; ngx_http_complex_value_t value; } ngx_http_sub_pair_t; typedef struct { ngx_str_t match; ngx_http_complex_value_t *value; } ngx_http_sub_match_t; typedef struct { ngx_uint_t min_match_len; ngx_uint_t max_match_len; u_char index[257]; u_char shift[256]; } ngx_http_sub_tables_t; typedef struct { ngx_uint_t dynamic; /* unsigned dynamic:1; */ ngx_array_t *pairs; ngx_http_sub_tables_t *tables; ngx_hash_t types; ngx_flag_t once; ngx_flag_t last_modified; ngx_array_t *types_keys; ngx_array_t *matches; } ngx_http_sub_loc_conf_t; typedef struct { ngx_str_t saved; ngx_str_t looked; ngx_uint_t once; /* unsigned once:1 */ ngx_buf_t *buf; u_char *pos; u_char *copy_start; u_char *copy_end; ngx_chain_t *in; ngx_chain_t *out; ngx_chain_t **last_out; ngx_chain_t *busy; ngx_chain_t *free; ngx_str_t *sub; ngx_uint_t applied; ngx_int_t offset; ngx_uint_t index; ngx_http_sub_tables_t *tables; ngx_array_t *matches; } ngx_http_sub_ctx_t; static ngx_uint_t ngx_http_sub_cmp_index; static ngx_int_t ngx_http_sub_output(ngx_http_request_t *r, ngx_http_sub_ctx_t *ctx); static ngx_int_t ngx_http_sub_parse(ngx_http_request_t *r, ngx_http_sub_ctx_t *ctx, ngx_uint_t flush); static ngx_int_t ngx_http_sub_match(ngx_http_sub_ctx_t *ctx, ngx_int_t start, ngx_str_t *m); static char * ngx_http_sub_filter(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static void *ngx_http_sub_create_conf(ngx_conf_t *cf); static char *ngx_http_sub_merge_conf(ngx_conf_t *cf, void *parent, void *child); static void ngx_http_sub_init_tables(ngx_http_sub_tables_t *tables, ngx_http_sub_match_t *match, ngx_uint_t n); static ngx_int_t ngx_http_sub_cmp_matches(const void *one, const void *two); static ngx_int_t ngx_http_sub_filter_init(ngx_conf_t *cf); static ngx_command_t ngx_http_sub_filter_commands[] = { { ngx_string("sub_filter"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2, ngx_http_sub_filter, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("sub_filter_types"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE, ngx_http_types_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_sub_loc_conf_t, types_keys), &ngx_http_html_default_types[0] }, { ngx_string("sub_filter_once"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_sub_loc_conf_t, once), NULL }, { ngx_string("sub_filter_last_modified"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_sub_loc_conf_t, last_modified), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_sub_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_sub_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_sub_create_conf, /* create location configuration */ ngx_http_sub_merge_conf /* merge location configuration */ }; ngx_module_t ngx_http_sub_filter_module = { NGX_MODULE_V1, &ngx_http_sub_filter_module_ctx, /* module context */ ngx_http_sub_filter_commands, /* module directives */ NGX_HTTP_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_http_output_header_filter_pt ngx_http_next_header_filter; static ngx_http_output_body_filter_pt ngx_http_next_body_filter; static ngx_int_t ngx_http_sub_header_filter(ngx_http_request_t *r) { ngx_str_t *m; ngx_uint_t i, j, n; ngx_http_sub_ctx_t *ctx; ngx_http_sub_pair_t *pairs; ngx_http_sub_match_t *matches; ngx_http_sub_loc_conf_t *slcf; slcf = ngx_http_get_module_loc_conf(r, ngx_http_sub_filter_module); if (slcf->pairs == NULL || r->headers_out.content_length_n == 0 || ngx_http_test_content_type(r, &slcf->types) == NULL) { return ngx_http_next_header_filter(r); } ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_sub_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } if (slcf->dynamic == 0) { ctx->tables = slcf->tables; ctx->matches = slcf->matches; } else { pairs = slcf->pairs->elts; n = slcf->pairs->nelts; matches = ngx_pcalloc(r->pool, sizeof(ngx_http_sub_match_t) * n); if (matches == NULL) { return NGX_ERROR; } j = 0; for (i = 0; i < n; i++) { matches[j].value = &pairs[i].value; if (pairs[i].match.lengths == NULL) { matches[j].match = pairs[i].match.value; j++; continue; } m = &matches[j].match; if (ngx_http_complex_value(r, &pairs[i].match, m) != NGX_OK) { return NGX_ERROR; } if (m->len == 0) { continue; } ngx_strlow(m->data, m->data, m->len); j++; } if (j == 0) { return ngx_http_next_header_filter(r); } ctx->matches = ngx_palloc(r->pool, sizeof(ngx_array_t)); if (ctx->matches == NULL) { return NGX_ERROR; } ctx->matches->elts = matches; ctx->matches->nelts = j; ctx->tables = ngx_palloc(r->pool, sizeof(ngx_http_sub_tables_t)); if (ctx->tables == NULL) { return NGX_ERROR; } ngx_http_sub_init_tables(ctx->tables, ctx->matches->elts, ctx->matches->nelts); } ctx->saved.data = ngx_pnalloc(r->pool, ctx->tables->max_match_len - 1); if (ctx->saved.data == NULL) { return NGX_ERROR; } ctx->looked.data = ngx_pnalloc(r->pool, ctx->tables->max_match_len - 1); if (ctx->looked.data == NULL) { return NGX_ERROR; } ngx_http_set_ctx(r, ctx, ngx_http_sub_filter_module); ctx->offset = ctx->tables->min_match_len - 1; ctx->last_out = &ctx->out; r->filter_need_in_memory = 1; if (r == r->main) { ngx_http_clear_content_length(r); if (!slcf->last_modified) { ngx_http_clear_last_modified(r); ngx_http_clear_etag(r); } else { ngx_http_weak_etag(r); } } return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_sub_body_filter(ngx_http_request_t *r, ngx_chain_t *in) { ngx_int_t rc; ngx_buf_t *b; ngx_str_t *sub; ngx_uint_t flush, last; ngx_chain_t *cl; ngx_http_sub_ctx_t *ctx; ngx_http_sub_match_t *match; ngx_http_sub_loc_conf_t *slcf; ctx = ngx_http_get_module_ctx(r, ngx_http_sub_filter_module); if (ctx == NULL) { return ngx_http_next_body_filter(r, in); } if ((in == NULL && ctx->buf == NULL && ctx->in == NULL && ctx->busy == NULL)) { return ngx_http_next_body_filter(r, in); } if (ctx->once && (ctx->buf == NULL || ctx->in == NULL)) { if (ctx->busy) { if (ngx_http_sub_output(r, ctx) == NGX_ERROR) { return NGX_ERROR; } } return ngx_http_next_body_filter(r, in); } /* add the incoming chain to the chain ctx->in */ if (in) { if (ngx_chain_add_copy(r->pool, &ctx->in, in) != NGX_OK) { return NGX_ERROR; } } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http sub filter \"%V\"", &r->uri); flush = 0; last = 0; while (ctx->in || ctx->buf) { if (ctx->buf == NULL) { ctx->buf = ctx->in->buf; ctx->in = ctx->in->next; ctx->pos = ctx->buf->pos; } if (ctx->buf->flush || ctx->buf->recycled) { flush = 1; } if (ctx->in == NULL) { last = flush; } b = NULL; while (ctx->pos < ctx->buf->last) { rc = ngx_http_sub_parse(r, ctx, last); ngx_log_debug4(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "parse: %i, looked: \"%V\" %p-%p", rc, &ctx->looked, ctx->copy_start, ctx->copy_end); if (rc == NGX_ERROR) { return rc; } if (ctx->saved.len) { ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "saved: \"%V\"", &ctx->saved); cl = ngx_chain_get_free_buf(r->pool, &ctx->free); if (cl == NULL) { return NGX_ERROR; } b = cl->buf; ngx_memzero(b, sizeof(ngx_buf_t)); b->pos = ngx_pnalloc(r->pool, ctx->saved.len); if (b->pos == NULL) { return NGX_ERROR; } ngx_memcpy(b->pos, ctx->saved.data, ctx->saved.len); b->last = b->pos + ctx->saved.len; b->memory = 1; *ctx->last_out = cl; ctx->last_out = &cl->next; ctx->saved.len = 0; } if (ctx->copy_start != ctx->copy_end) { cl = ngx_chain_get_free_buf(r->pool, &ctx->free); if (cl == NULL) { return NGX_ERROR; } b = cl->buf; ngx_memcpy(b, ctx->buf, sizeof(ngx_buf_t)); b->pos = ctx->copy_start; b->last = ctx->copy_end; b->shadow = NULL; b->last_buf = 0; b->last_in_chain = 0; b->recycled = 0; if (b->in_file) { b->file_last = b->file_pos + (b->last - ctx->buf->pos); b->file_pos += b->pos - ctx->buf->pos; } *ctx->last_out = cl; ctx->last_out = &cl->next; } if (rc == NGX_AGAIN) { continue; } /* rc == NGX_OK */ cl = ngx_chain_get_free_buf(r->pool, &ctx->free); if (cl == NULL) { return NGX_ERROR; } b = cl->buf; ngx_memzero(b, sizeof(ngx_buf_t)); slcf = ngx_http_get_module_loc_conf(r, ngx_http_sub_filter_module); if (ctx->sub == NULL) { ctx->sub = ngx_pcalloc(r->pool, sizeof(ngx_str_t) * ctx->matches->nelts); if (ctx->sub == NULL) { return NGX_ERROR; } } sub = &ctx->sub[ctx->index]; if (sub->data == NULL) { match = ctx->matches->elts; if (ngx_http_complex_value(r, match[ctx->index].value, sub) != NGX_OK) { return NGX_ERROR; } } if (sub->len) { b->memory = 1; b->pos = sub->data; b->last = sub->data + sub->len; } else { b->sync = 1; } *ctx->last_out = cl; ctx->last_out = &cl->next; ctx->index = 0; ctx->once = slcf->once && (++ctx->applied == ctx->matches->nelts); continue; } if (ctx->looked.len && (ctx->buf->last_buf || ctx->buf->last_in_chain)) { cl = ngx_chain_get_free_buf(r->pool, &ctx->free); if (cl == NULL) { return NGX_ERROR; } b = cl->buf; ngx_memzero(b, sizeof(ngx_buf_t)); b->pos = ctx->looked.data; b->last = b->pos + ctx->looked.len; b->memory = 1; *ctx->last_out = cl; ctx->last_out = &cl->next; ctx->looked.len = 0; } if (ctx->buf->last_buf || ctx->buf->flush || ctx->buf->sync || ngx_buf_in_memory(ctx->buf)) { if (b == NULL) { cl = ngx_chain_get_free_buf(r->pool, &ctx->free); if (cl == NULL) { return NGX_ERROR; } b = cl->buf; ngx_memzero(b, sizeof(ngx_buf_t)); b->sync = 1; *ctx->last_out = cl; ctx->last_out = &cl->next; } b->last_buf = ctx->buf->last_buf; b->last_in_chain = ctx->buf->last_in_chain; b->flush = ctx->buf->flush; b->shadow = ctx->buf; b->recycled = ctx->buf->recycled; } ctx->buf = NULL; } if (ctx->out == NULL && ctx->busy == NULL) { return NGX_OK; } return ngx_http_sub_output(r, ctx); } static ngx_int_t ngx_http_sub_output(ngx_http_request_t *r, ngx_http_sub_ctx_t *ctx) { ngx_int_t rc; ngx_buf_t *b; ngx_chain_t *cl; #if 1 b = NULL; for (cl = ctx->out; cl; cl = cl->next) { ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "sub out: %p %p", cl->buf, cl->buf->pos); if (cl->buf == b) { ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0, "the same buf was used in sub"); ngx_debug_point(); return NGX_ERROR; } b = cl->buf; } #endif rc = ngx_http_next_body_filter(r, ctx->out); if (ctx->busy == NULL) { ctx->busy = ctx->out; } else { for (cl = ctx->busy; cl->next; cl = cl->next) { /* void */ } cl->next = ctx->out; } ctx->out = NULL; ctx->last_out = &ctx->out; while (ctx->busy) { cl = ctx->busy; b = cl->buf; if (ngx_buf_size(b) != 0) { break; } if (b->shadow) { b->shadow->pos = b->shadow->last; } ctx->busy = cl->next; if (ngx_buf_in_memory(b) || b->in_file) { /* add data bufs only to the free buf chain */ cl->next = ctx->free; ctx->free = cl; } } if (ctx->in || ctx->buf) { r->buffered |= NGX_HTTP_SUB_BUFFERED; } else { r->buffered &= ~NGX_HTTP_SUB_BUFFERED; } return rc; } static ngx_int_t ngx_http_sub_parse(ngx_http_request_t *r, ngx_http_sub_ctx_t *ctx, ngx_uint_t flush) { u_char *p, c; ngx_str_t *m; ngx_int_t offset, start, next, end, len, rc; ngx_uint_t shift, i, j; ngx_http_sub_match_t *match; ngx_http_sub_tables_t *tables; ngx_http_sub_loc_conf_t *slcf; slcf = ngx_http_get_module_loc_conf(r, ngx_http_sub_filter_module); tables = ctx->tables; match = ctx->matches->elts; offset = ctx->offset; end = ctx->buf->last - ctx->pos; if (ctx->once) { /* sets start and next to end */ offset = end + (ngx_int_t) tables->min_match_len - 1; goto again; } while (offset < end) { c = offset < 0 ? ctx->looked.data[ctx->looked.len + offset] : ctx->pos[offset]; c = ngx_tolower(c); shift = tables->shift[c]; if (shift > 0) { offset += shift; continue; } /* a potential match */ start = offset - (ngx_int_t) tables->min_match_len + 1; i = ngx_max((ngx_uint_t) tables->index[c], ctx->index); j = tables->index[c + 1]; while (i != j) { if (slcf->once && ctx->sub && ctx->sub[i].data) { goto next; } m = &match[i].match; rc = ngx_http_sub_match(ctx, start, m); if (rc == NGX_DECLINED) { goto next; } ctx->index = i; if (rc == NGX_AGAIN) { goto again; } ctx->offset = offset + (ngx_int_t) m->len; next = start + (ngx_int_t) m->len; end = ngx_max(next, 0); rc = NGX_OK; goto done; next: i++; } offset++; ctx->index = 0; } if (flush) { for ( ;; ) { start = offset - (ngx_int_t) tables->min_match_len + 1; if (start >= end) { break; } for (i = 0; i < ctx->matches->nelts; i++) { m = &match[i].match; if (ngx_http_sub_match(ctx, start, m) == NGX_AGAIN) { goto again; } } offset++; } } again: ctx->offset = offset; start = offset - (ngx_int_t) tables->min_match_len + 1; next = start; rc = NGX_AGAIN; done: /* send [ - looked.len, start ] to client */ ctx->saved.len = ctx->looked.len + ngx_min(start, 0); ngx_memcpy(ctx->saved.data, ctx->looked.data, ctx->saved.len); ctx->copy_start = ctx->pos; ctx->copy_end = ctx->pos + ngx_max(start, 0); /* save [ next, end ] in looked */ len = ngx_min(next, 0); p = ctx->looked.data; p = ngx_movemem(p, p + ctx->looked.len + len, - len); len = ngx_max(next, 0); p = ngx_cpymem(p, ctx->pos + len, end - len); ctx->looked.len = p - ctx->looked.data; /* update position */ ctx->pos += end; ctx->offset -= end; return rc; } static ngx_int_t ngx_http_sub_match(ngx_http_sub_ctx_t *ctx, ngx_int_t start, ngx_str_t *m) { u_char *p, *last, *pat, *pat_end; pat = m->data; pat_end = m->data + m->len; if (start >= 0) { p = ctx->pos + start; } else { last = ctx->looked.data + ctx->looked.len; p = last + start; while (p < last && pat < pat_end) { if (ngx_tolower(*p) != *pat) { return NGX_DECLINED; } p++; pat++; } p = ctx->pos; } while (p < ctx->buf->last && pat < pat_end) { if (ngx_tolower(*p) != *pat) { return NGX_DECLINED; } p++; pat++; } if (pat != pat_end) { /* partial match */ return NGX_AGAIN; } return NGX_OK; } static char * ngx_http_sub_filter(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_sub_loc_conf_t *slcf = conf; ngx_str_t *value; ngx_http_sub_pair_t *pair; ngx_http_compile_complex_value_t ccv; value = cf->args->elts; if (value[1].len == 0) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "empty search pattern"); return NGX_CONF_ERROR; } if (slcf->pairs == NULL) { slcf->pairs = ngx_array_create(cf->pool, 1, sizeof(ngx_http_sub_pair_t)); if (slcf->pairs == NULL) { return NGX_CONF_ERROR; } } if (slcf->pairs->nelts == 255) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "number of search patterns exceeds 255"); return NGX_CONF_ERROR; } ngx_strlow(value[1].data, value[1].data, value[1].len); pair = ngx_array_push(slcf->pairs); if (pair == NULL) { return NGX_CONF_ERROR; } ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[1]; ccv.complex_value = &pair->match; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } if (ccv.complex_value->lengths != NULL) { slcf->dynamic = 1; } else { ngx_strlow(pair->match.value.data, pair->match.value.data, pair->match.value.len); } ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[2]; ccv.complex_value = &pair->value; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } return NGX_CONF_OK; } static void * ngx_http_sub_create_conf(ngx_conf_t *cf) { ngx_http_sub_loc_conf_t *slcf; slcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_sub_loc_conf_t)); if (slcf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->dynamic = 0; * conf->pairs = NULL; * conf->tables = NULL; * conf->types = { NULL }; * conf->types_keys = NULL; * conf->matches = NULL; */ slcf->once = NGX_CONF_UNSET; slcf->last_modified = NGX_CONF_UNSET; return slcf; } static char * ngx_http_sub_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_uint_t i, n; ngx_http_sub_pair_t *pairs; ngx_http_sub_match_t *matches; ngx_http_sub_loc_conf_t *prev = parent; ngx_http_sub_loc_conf_t *conf = child; ngx_conf_merge_value(conf->once, prev->once, 1); ngx_conf_merge_value(conf->last_modified, prev->last_modified, 0); if (ngx_http_merge_types(cf, &conf->types_keys, &conf->types, &prev->types_keys, &prev->types, ngx_http_html_default_types) != NGX_OK) { return NGX_CONF_ERROR; } if (conf->pairs == NULL) { conf->dynamic = prev->dynamic; conf->pairs = prev->pairs; conf->matches = prev->matches; conf->tables = prev->tables; } if (conf->pairs && conf->dynamic == 0 && conf->tables == NULL) { pairs = conf->pairs->elts; n = conf->pairs->nelts; matches = ngx_palloc(cf->pool, sizeof(ngx_http_sub_match_t) * n); if (matches == NULL) { return NGX_CONF_ERROR; } for (i = 0; i < n; i++) { matches[i].match = pairs[i].match.value; matches[i].value = &pairs[i].value; } conf->matches = ngx_palloc(cf->pool, sizeof(ngx_array_t)); if (conf->matches == NULL) { return NGX_CONF_ERROR; } conf->matches->elts = matches; conf->matches->nelts = n; conf->tables = ngx_palloc(cf->pool, sizeof(ngx_http_sub_tables_t)); if (conf->tables == NULL) { return NGX_CONF_ERROR; } ngx_http_sub_init_tables(conf->tables, conf->matches->elts, conf->matches->nelts); } return NGX_CONF_OK; } static void ngx_http_sub_init_tables(ngx_http_sub_tables_t *tables, ngx_http_sub_match_t *match, ngx_uint_t n) { u_char c; ngx_uint_t i, j, min, max, ch; min = match[0].match.len; max = match[0].match.len; for (i = 1; i < n; i++) { min = ngx_min(min, match[i].match.len); max = ngx_max(max, match[i].match.len); } tables->min_match_len = min; tables->max_match_len = max; ngx_http_sub_cmp_index = tables->min_match_len - 1; ngx_sort(match, n, sizeof(ngx_http_sub_match_t), ngx_http_sub_cmp_matches); min = ngx_min(min, 255); ngx_memset(tables->shift, min, 256); ch = 0; for (i = 0; i < n; i++) { for (j = 0; j < min; j++) { c = match[i].match.data[tables->min_match_len - 1 - j]; tables->shift[c] = ngx_min(tables->shift[c], (u_char) j); } c = match[i].match.data[tables->min_match_len - 1]; while (ch <= (ngx_uint_t) c) { tables->index[ch++] = (u_char) i; } } while (ch < 257) { tables->index[ch++] = (u_char) n; } } static ngx_int_t ngx_http_sub_cmp_matches(const void *one, const void *two) { ngx_int_t c1, c2; ngx_http_sub_match_t *first, *second; first = (ngx_http_sub_match_t *) one; second = (ngx_http_sub_match_t *) two; c1 = first->match.data[ngx_http_sub_cmp_index]; c2 = second->match.data[ngx_http_sub_cmp_index]; return c1 - c2; } static ngx_int_t ngx_http_sub_filter_init(ngx_conf_t *cf) { ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_sub_header_filter; ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_sub_body_filter; return NGX_OK; }