Mercurial > hg > nginx
view src/http/modules/ngx_http_slice_filter_module.c @ 7281:bd6563e81cea
Limit req: improved handling of negative times.
Negative times can appear since workers only update time on an event
loop iteration start. If a worker was blocked for a long time during
an event loop iteration, it is possible that another worker already
updated the time stored in the node. As such, time since last update
of the node (ms) will be negative.
Previous code used ngx_abs(ms) in the calculations. That is, negative
times were effectively treated as positive ones. As a result, it was
not possible to maintain high request rates, where the same node can be
updated multiple times from during an event loop iteration.
In particular, this affected setups with many SSL handshakes, see
http://mailman.nginx.org/pipermail/nginx/2018-May/056291.html.
Fix is to only update the last update time stored in the node if the
new time is larger than previously stored one. If a future time is
stored in the node, we preserve this time as is.
To prevent breaking things on platforms without monotonic time available
if system time is updated backwards, a safety limit of 60 seconds is
used. If the time stored in the node is more than 60 seconds in the future,
we assume that the time was changed backwards and update lr->last
to the current time.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 30 May 2018 15:40:34 +0300 |
parents | f583559aadc7 |
children | 32a343635b50 |
line wrap: on
line source
/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { size_t size; } ngx_http_slice_loc_conf_t; typedef struct { off_t start; off_t end; ngx_str_t range; ngx_str_t etag; unsigned last:1; unsigned active:1; ngx_http_request_t *sr; } ngx_http_slice_ctx_t; typedef struct { off_t start; off_t end; off_t complete_length; } ngx_http_slice_content_range_t; static ngx_int_t ngx_http_slice_header_filter(ngx_http_request_t *r); static ngx_int_t ngx_http_slice_body_filter(ngx_http_request_t *r, ngx_chain_t *in); static ngx_int_t ngx_http_slice_parse_content_range(ngx_http_request_t *r, ngx_http_slice_content_range_t *cr); static ngx_int_t ngx_http_slice_range_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); static off_t ngx_http_slice_get_start(ngx_http_request_t *r); static void *ngx_http_slice_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_slice_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_slice_add_variables(ngx_conf_t *cf); static ngx_int_t ngx_http_slice_init(ngx_conf_t *cf); static ngx_command_t ngx_http_slice_filter_commands[] = { { ngx_string("slice"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_conf_set_size_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_slice_loc_conf_t, size), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_slice_filter_module_ctx = { ngx_http_slice_add_variables, /* preconfiguration */ ngx_http_slice_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_slice_create_loc_conf, /* create location configuration */ ngx_http_slice_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_slice_filter_module = { NGX_MODULE_V1, &ngx_http_slice_filter_module_ctx, /* module context */ ngx_http_slice_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_str_t ngx_http_slice_range_name = ngx_string("slice_range"); 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_slice_header_filter(ngx_http_request_t *r) { off_t end; ngx_int_t rc; ngx_table_elt_t *h; ngx_http_slice_ctx_t *ctx; ngx_http_slice_loc_conf_t *slcf; ngx_http_slice_content_range_t cr; ctx = ngx_http_get_module_ctx(r, ngx_http_slice_filter_module); if (ctx == NULL) { return ngx_http_next_header_filter(r); } if (r->headers_out.status != NGX_HTTP_PARTIAL_CONTENT) { if (r == r->main) { ngx_http_set_ctx(r, NULL, ngx_http_slice_filter_module); return ngx_http_next_header_filter(r); } ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "unexpected status code %ui in slice response", r->headers_out.status); return NGX_ERROR; } h = r->headers_out.etag; if (ctx->etag.len) { if (h == NULL || h->value.len != ctx->etag.len || ngx_strncmp(h->value.data, ctx->etag.data, ctx->etag.len) != 0) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "etag mismatch in slice response"); return NGX_ERROR; } } if (h) { ctx->etag = h->value; } if (ngx_http_slice_parse_content_range(r, &cr) != NGX_OK) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "invalid range in slice response"); return NGX_ERROR; } if (cr.complete_length == -1) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "no complete length in slice response"); return NGX_ERROR; } ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http slice response range: %O-%O/%O", cr.start, cr.end, cr.complete_length); slcf = ngx_http_get_module_loc_conf(r, ngx_http_slice_filter_module); end = ngx_min(cr.start + (off_t) slcf->size, cr.complete_length); if (cr.start != ctx->start || cr.end != end) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "unexpected range in slice response: %O-%O", cr.start, cr.end); return NGX_ERROR; } ctx->start = end; ctx->active = 1; r->headers_out.status = NGX_HTTP_OK; r->headers_out.status_line.len = 0; r->headers_out.content_length_n = cr.complete_length; r->headers_out.content_offset = cr.start; r->headers_out.content_range->hash = 0; r->headers_out.content_range = NULL; r->allow_ranges = 1; r->subrequest_ranges = 1; r->single_range = 1; rc = ngx_http_next_header_filter(r); if (r != r->main) { return rc; } r->preserve_body = 1; if (r->headers_out.status == NGX_HTTP_PARTIAL_CONTENT) { if (ctx->start + (off_t) slcf->size <= r->headers_out.content_offset) { ctx->start = slcf->size * (r->headers_out.content_offset / slcf->size); } ctx->end = r->headers_out.content_offset + r->headers_out.content_length_n; } else { ctx->end = cr.complete_length; } return rc; } static ngx_int_t ngx_http_slice_body_filter(ngx_http_request_t *r, ngx_chain_t *in) { ngx_int_t rc; ngx_chain_t *cl; ngx_http_slice_ctx_t *ctx; ngx_http_slice_loc_conf_t *slcf; ctx = ngx_http_get_module_ctx(r, ngx_http_slice_filter_module); if (ctx == NULL || r != r->main) { return ngx_http_next_body_filter(r, in); } for (cl = in; cl; cl = cl->next) { if (cl->buf->last_buf) { cl->buf->last_buf = 0; cl->buf->last_in_chain = 1; cl->buf->sync = 1; ctx->last = 1; } } rc = ngx_http_next_body_filter(r, in); if (rc == NGX_ERROR || !ctx->last) { return rc; } if (ctx->sr && !ctx->sr->done) { return rc; } if (!ctx->active) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "missing slice response"); return NGX_ERROR; } if (ctx->start >= ctx->end) { ngx_http_set_ctx(r, NULL, ngx_http_slice_filter_module); ngx_http_send_special(r, NGX_HTTP_LAST); return rc; } if (r->buffered) { return rc; } if (ngx_http_subrequest(r, &r->uri, &r->args, &ctx->sr, NULL, NGX_HTTP_SUBREQUEST_CLONE) != NGX_OK) { return NGX_ERROR; } ngx_http_set_ctx(ctx->sr, ctx, ngx_http_slice_filter_module); slcf = ngx_http_get_module_loc_conf(r, ngx_http_slice_filter_module); ctx->range.len = ngx_sprintf(ctx->range.data, "bytes=%O-%O", ctx->start, ctx->start + (off_t) slcf->size - 1) - ctx->range.data; ctx->active = 0; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http slice subrequest: \"%V\"", &ctx->range); return rc; } static ngx_int_t ngx_http_slice_parse_content_range(ngx_http_request_t *r, ngx_http_slice_content_range_t *cr) { off_t start, end, complete_length, cutoff, cutlim; u_char *p; ngx_table_elt_t *h; h = r->headers_out.content_range; if (h == NULL || h->value.len < 7 || ngx_strncmp(h->value.data, "bytes ", 6) != 0) { return NGX_ERROR; } p = h->value.data + 6; cutoff = NGX_MAX_OFF_T_VALUE / 10; cutlim = NGX_MAX_OFF_T_VALUE % 10; start = 0; end = 0; complete_length = 0; while (*p == ' ') { p++; } if (*p < '0' || *p > '9') { return NGX_ERROR; } while (*p >= '0' && *p <= '9') { if (start >= cutoff && (start > cutoff || *p - '0' > cutlim)) { return NGX_ERROR; } start = start * 10 + (*p++ - '0'); } while (*p == ' ') { p++; } if (*p++ != '-') { return NGX_ERROR; } while (*p == ' ') { p++; } if (*p < '0' || *p > '9') { return NGX_ERROR; } while (*p >= '0' && *p <= '9') { if (end >= cutoff && (end > cutoff || *p - '0' > cutlim)) { return NGX_ERROR; } end = end * 10 + (*p++ - '0'); } end++; while (*p == ' ') { p++; } if (*p++ != '/') { return NGX_ERROR; } while (*p == ' ') { p++; } if (*p != '*') { if (*p < '0' || *p > '9') { return NGX_ERROR; } while (*p >= '0' && *p <= '9') { if (complete_length >= cutoff && (complete_length > cutoff || *p - '0' > cutlim)) { return NGX_ERROR; } complete_length = complete_length * 10 + (*p++ - '0'); } } else { complete_length = -1; p++; } while (*p == ' ') { p++; } if (*p != '\0') { return NGX_ERROR; } cr->start = start; cr->end = end; cr->complete_length = complete_length; return NGX_OK; } static ngx_int_t ngx_http_slice_range_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { u_char *p; ngx_http_slice_ctx_t *ctx; ngx_http_slice_loc_conf_t *slcf; ctx = ngx_http_get_module_ctx(r, ngx_http_slice_filter_module); if (ctx == NULL) { if (r != r->main || r->headers_out.status) { v->not_found = 1; return NGX_OK; } slcf = ngx_http_get_module_loc_conf(r, ngx_http_slice_filter_module); if (slcf->size == 0) { v->not_found = 1; return NGX_OK; } ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_slice_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ngx_http_set_ctx(r, ctx, ngx_http_slice_filter_module); p = ngx_pnalloc(r->pool, sizeof("bytes=-") - 1 + 2 * NGX_OFF_T_LEN); if (p == NULL) { return NGX_ERROR; } ctx->start = slcf->size * (ngx_http_slice_get_start(r) / slcf->size); ctx->range.data = p; ctx->range.len = ngx_sprintf(p, "bytes=%O-%O", ctx->start, ctx->start + (off_t) slcf->size - 1) - p; } v->data = ctx->range.data; v->valid = 1; v->not_found = 0; v->no_cacheable = 1; v->len = ctx->range.len; return NGX_OK; } static off_t ngx_http_slice_get_start(ngx_http_request_t *r) { off_t start, cutoff, cutlim; u_char *p; ngx_table_elt_t *h; if (r->headers_in.if_range) { return 0; } h = r->headers_in.range; if (h == NULL || h->value.len < 7 || ngx_strncasecmp(h->value.data, (u_char *) "bytes=", 6) != 0) { return 0; } p = h->value.data + 6; if (ngx_strchr(p, ',')) { return 0; } while (*p == ' ') { p++; } if (*p == '-') { return 0; } cutoff = NGX_MAX_OFF_T_VALUE / 10; cutlim = NGX_MAX_OFF_T_VALUE % 10; start = 0; while (*p >= '0' && *p <= '9') { if (start >= cutoff && (start > cutoff || *p - '0' > cutlim)) { return 0; } start = start * 10 + (*p++ - '0'); } return start; } static void * ngx_http_slice_create_loc_conf(ngx_conf_t *cf) { ngx_http_slice_loc_conf_t *slcf; slcf = ngx_palloc(cf->pool, sizeof(ngx_http_slice_loc_conf_t)); if (slcf == NULL) { return NULL; } slcf->size = NGX_CONF_UNSET_SIZE; return slcf; } static char * ngx_http_slice_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_slice_loc_conf_t *prev = parent; ngx_http_slice_loc_conf_t *conf = child; ngx_conf_merge_size_value(conf->size, prev->size, 0); return NGX_CONF_OK; } static ngx_int_t ngx_http_slice_add_variables(ngx_conf_t *cf) { ngx_http_variable_t *var; var = ngx_http_add_variable(cf, &ngx_http_slice_range_name, 0); if (var == NULL) { return NGX_ERROR; } var->get_handler = ngx_http_slice_range_variable; return NGX_OK; } static ngx_int_t ngx_http_slice_init(ngx_conf_t *cf) { ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_slice_header_filter; ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_slice_body_filter; return NGX_OK; }