Mercurial > hg > nginx-quic
view src/stream/ngx_stream_ssl_preread_module.c @ 6876:a5d1b1383dea
Upstream: fixed cache corruption and socket leaks with aio_write.
The ngx_event_pipe() function wasn't called on write events with
wev->delayed set. As a result, threaded writing results weren't
properly collected in ngx_event_pipe_write_to_downstream() when a
write event was triggered for a completed write.
Further, this wasn't detected, as p->aio was reset by a thread completion
handler, and results were later collected in ngx_event_pipe_read_upstream()
instead of scheduling a new write of additional data. If this happened
on the last reading from an upstream, last part of the response was never
written to the cache file.
Similar problems might also happen in case of timeouts when writing to
client, as this also results in ngx_event_pipe() not being called on write
events. In this scenario socket leaks were observed.
Fix is to check if p->writing is set in ngx_event_pipe_read_upstream(), and
therefore collect results of previous write operations in case of read events
as well, similar to how we do so in ngx_event_pipe_write_downstream().
This is enough to fix the wev->delayed case. Additionally, we now call
ngx_event_pipe() from ngx_http_upstream_process_request() if there are
uncollected write operations (p->writing and !p->aio). This also fixes
the wev->timedout case.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Fri, 20 Jan 2017 21:14:19 +0300 |
parents | 01adb18a5d23 |
children | 2a288909abc6 |
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/* * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> typedef struct { ngx_flag_t enabled; } ngx_stream_ssl_preread_srv_conf_t; typedef struct { size_t left; size_t size; u_char *pos; u_char *dst; u_char buf[4]; ngx_str_t host; ngx_log_t *log; ngx_pool_t *pool; ngx_uint_t state; } ngx_stream_ssl_preread_ctx_t; static ngx_int_t ngx_stream_ssl_preread_handler(ngx_stream_session_t *s); static ngx_int_t ngx_stream_ssl_preread_parse_record( ngx_stream_ssl_preread_ctx_t *ctx, u_char *pos, u_char *last); static ngx_int_t ngx_stream_ssl_preread_server_name_variable( ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data); static ngx_int_t ngx_stream_ssl_preread_add_variables(ngx_conf_t *cf); static void *ngx_stream_ssl_preread_create_srv_conf(ngx_conf_t *cf); static char *ngx_stream_ssl_preread_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_stream_ssl_preread_init(ngx_conf_t *cf); static ngx_command_t ngx_stream_ssl_preread_commands[] = { { ngx_string("ssl_preread"), NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_STREAM_SRV_CONF_OFFSET, offsetof(ngx_stream_ssl_preread_srv_conf_t, enabled), NULL }, ngx_null_command }; static ngx_stream_module_t ngx_stream_ssl_preread_module_ctx = { ngx_stream_ssl_preread_add_variables, /* preconfiguration */ ngx_stream_ssl_preread_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_stream_ssl_preread_create_srv_conf, /* create server configuration */ ngx_stream_ssl_preread_merge_srv_conf /* merge server configuration */ }; ngx_module_t ngx_stream_ssl_preread_module = { NGX_MODULE_V1, &ngx_stream_ssl_preread_module_ctx, /* module context */ ngx_stream_ssl_preread_commands, /* module directives */ NGX_STREAM_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_stream_variable_t ngx_stream_ssl_preread_vars[] = { { ngx_string("ssl_preread_server_name"), NULL, ngx_stream_ssl_preread_server_name_variable, 0, 0, 0 }, { ngx_null_string, NULL, NULL, 0, 0, 0 } }; static ngx_int_t ngx_stream_ssl_preread_handler(ngx_stream_session_t *s) { u_char *last, *p; size_t len; ngx_int_t rc; ngx_connection_t *c; ngx_stream_ssl_preread_ctx_t *ctx; ngx_stream_ssl_preread_srv_conf_t *sscf; c = s->connection; ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0, "ssl preread handler"); sscf = ngx_stream_get_module_srv_conf(s, ngx_stream_ssl_preread_module); if (!sscf->enabled) { return NGX_DECLINED; } if (c->type != SOCK_STREAM) { return NGX_DECLINED; } if (c->buffer == NULL) { return NGX_AGAIN; } ctx = ngx_stream_get_module_ctx(s, ngx_stream_ssl_preread_module); if (ctx == NULL) { ctx = ngx_pcalloc(c->pool, sizeof(ngx_stream_ssl_preread_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ngx_stream_set_ctx(s, ctx, ngx_stream_ssl_preread_module); ctx->pool = c->pool; ctx->log = c->log; ctx->pos = c->buffer->pos; } p = ctx->pos; last = c->buffer->last; while (last - p >= 5) { if (p[0] != 0x16) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, ctx->log, 0, "ssl preread: not a handshake"); return NGX_DECLINED; } if (p[1] != 3) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, ctx->log, 0, "ssl preread: unsupported SSL version"); return NGX_DECLINED; } len = (p[3] << 8) + p[4]; /* read the whole record before parsing */ if ((size_t) (last - p) < len + 5) { break; } p += 5; rc = ngx_stream_ssl_preread_parse_record(ctx, p, p + len); if (rc != NGX_AGAIN) { return rc; } p += len; } ctx->pos = p; return NGX_AGAIN; } static ngx_int_t ngx_stream_ssl_preread_parse_record(ngx_stream_ssl_preread_ctx_t *ctx, u_char *pos, u_char *last) { size_t left, n, size; u_char *dst, *p; enum { sw_start = 0, sw_header, /* handshake msg_type, length */ sw_head_tail, /* version, random */ sw_sid_len, /* session_id length */ sw_sid, /* session_id */ sw_cs_len, /* cipher_suites length */ sw_cs, /* cipher_suites */ sw_cm_len, /* compression_methods length */ sw_cm, /* compression_methods */ sw_ext, /* extension */ sw_ext_header, /* extension_type, extension_data length */ sw_sni_len, /* SNI length */ sw_sni_host_head, /* SNI name_type, host_name length */ sw_sni_host /* SNI host_name */ } state; ngx_log_debug2(NGX_LOG_DEBUG_STREAM, ctx->log, 0, "ssl preread: state %ui left %z", ctx->state, ctx->left); state = ctx->state; size = ctx->size; left = ctx->left; dst = ctx->dst; p = ctx->buf; for ( ;; ) { n = ngx_min((size_t) (last - pos), size); if (dst) { dst = ngx_cpymem(dst, pos, n); } pos += n; size -= n; left -= n; if (size != 0) { break; } switch (state) { case sw_start: state = sw_header; dst = p; size = 4; left = size; break; case sw_header: if (p[0] != 1) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, ctx->log, 0, "ssl preread: not a client hello"); return NGX_DECLINED; } state = sw_head_tail; dst = NULL; size = 34; left = (p[1] << 16) + (p[2] << 8) + p[3]; break; case sw_head_tail: state = sw_sid_len; dst = p; size = 1; break; case sw_sid_len: state = sw_sid; dst = NULL; size = p[0]; break; case sw_sid: state = sw_cs_len; dst = p; size = 2; break; case sw_cs_len: state = sw_cs; dst = NULL; size = (p[0] << 8) + p[1]; break; case sw_cs: state = sw_cm_len; dst = p; size = 1; break; case sw_cm_len: state = sw_cm; dst = NULL; size = p[0]; break; case sw_cm: if (left == 0) { /* no extensions */ return NGX_OK; } state = sw_ext; dst = p; size = 2; break; case sw_ext: if (left == 0) { return NGX_OK; } state = sw_ext_header; dst = p; size = 4; break; case sw_ext_header: if (p[0] == 0 && p[1] == 0) { /* SNI extension */ state = sw_sni_len; dst = NULL; size = 2; break; } state = sw_ext; dst = NULL; size = (p[2] << 8) + p[3]; break; case sw_sni_len: state = sw_sni_host_head; dst = p; size = 3; break; case sw_sni_host_head: if (p[0] != 0) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, ctx->log, 0, "ssl preread: SNI hostname type is not DNS"); return NGX_DECLINED; } state = sw_sni_host; size = (p[1] << 8) + p[2]; ctx->host.data = ngx_pnalloc(ctx->pool, size); if (ctx->host.data == NULL) { return NGX_ERROR; } dst = ctx->host.data; break; case sw_sni_host: ctx->host.len = (p[1] << 8) + p[2]; ngx_log_debug1(NGX_LOG_DEBUG_STREAM, ctx->log, 0, "ssl preread: SNI hostname \"%V\"", &ctx->host); return NGX_OK; } if (left < size) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, ctx->log, 0, "ssl preread: failed to parse handshake"); return NGX_DECLINED; } } ctx->state = state; ctx->size = size; ctx->left = left; ctx->dst = dst; return NGX_AGAIN; } static ngx_int_t ngx_stream_ssl_preread_server_name_variable(ngx_stream_session_t *s, ngx_variable_value_t *v, uintptr_t data) { ngx_stream_ssl_preread_ctx_t *ctx; ctx = ngx_stream_get_module_ctx(s, ngx_stream_ssl_preread_module); if (ctx == NULL) { v->not_found = 1; return NGX_OK; } v->valid = 1; v->no_cacheable = 0; v->not_found = 0; v->len = ctx->host.len; v->data = ctx->host.data; return NGX_OK; } static ngx_int_t ngx_stream_ssl_preread_add_variables(ngx_conf_t *cf) { ngx_stream_variable_t *var, *v; for (v = ngx_stream_ssl_preread_vars; v->name.len; v++) { var = ngx_stream_add_variable(cf, &v->name, v->flags); if (var == NULL) { return NGX_ERROR; } var->get_handler = v->get_handler; var->data = v->data; } return NGX_OK; } static void * ngx_stream_ssl_preread_create_srv_conf(ngx_conf_t *cf) { ngx_stream_ssl_preread_srv_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_stream_ssl_preread_srv_conf_t)); if (conf == NULL) { return NULL; } conf->enabled = NGX_CONF_UNSET; return conf; } static char * ngx_stream_ssl_preread_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_stream_ssl_preread_srv_conf_t *prev = parent; ngx_stream_ssl_preread_srv_conf_t *conf = child; ngx_conf_merge_value(conf->enabled, prev->enabled, 0); return NGX_CONF_OK; } static ngx_int_t ngx_stream_ssl_preread_init(ngx_conf_t *cf) { ngx_stream_handler_pt *h; ngx_stream_core_main_conf_t *cmcf; cmcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_core_module); h = ngx_array_push(&cmcf->phases[NGX_STREAM_PREREAD_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_stream_ssl_preread_handler; return NGX_OK; }