Mercurial > hg > nginx
view src/http/modules/ngx_http_stub_status_module.c @ 5356:acd51b0f6fd4
Disable symlinks: use O_PATH to open path components.
It was introduced in Linux 2.6.39, glibc 2.14 and allows to obtain
file descriptors without actually opening files. Thus made it possible
to traverse path with openat() syscalls without the need to have read
permissions for path components. It is effectively emulates O_SEARCH
which is missing on Linux.
O_PATH is used in combination with O_RDONLY. The last one is ignored
if O_PATH is used, but it allows nginx to not fail when it was built on
modern system (i.e. glibc 2.14+) and run with a kernel older than 2.6.39.
Then O_PATH is unknown to the kernel and ignored, while O_RDONLY is used.
Sadly, fstat() is not working with O_PATH descriptors till Linux 3.6.
As a workaround we fallback to fstatat() with the AT_EMPTY_PATH flag
that was introduced at the same time as O_PATH.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Mon, 02 Sep 2013 08:07:59 +0400 |
parents | ee739104d164 |
children | 2cfc095a607a |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> static ngx_int_t ngx_http_stub_status_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); static ngx_int_t ngx_http_stub_status_add_variables(ngx_conf_t *cf); static char *ngx_http_set_status(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_status_commands[] = { { ngx_string("stub_status"), NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG, ngx_http_set_status, 0, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_stub_status_module_ctx = { ngx_http_stub_status_add_variables, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_stub_status_module = { NGX_MODULE_V1, &ngx_http_stub_status_module_ctx, /* module context */ ngx_http_status_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_variable_t ngx_http_stub_status_vars[] = { { ngx_string("connections_active"), NULL, ngx_http_stub_status_variable, 0, NGX_HTTP_VAR_NOCACHEABLE, 0 }, { ngx_string("connections_reading"), NULL, ngx_http_stub_status_variable, 1, NGX_HTTP_VAR_NOCACHEABLE, 0 }, { ngx_string("connections_writing"), NULL, ngx_http_stub_status_variable, 2, NGX_HTTP_VAR_NOCACHEABLE, 0 }, { ngx_string("connections_waiting"), NULL, ngx_http_stub_status_variable, 3, NGX_HTTP_VAR_NOCACHEABLE, 0 }, { ngx_null_string, NULL, NULL, 0, 0, 0 } }; static ngx_int_t ngx_http_status_handler(ngx_http_request_t *r) { size_t size; ngx_int_t rc; ngx_buf_t *b; ngx_chain_t out; ngx_atomic_int_t ap, hn, ac, rq, rd, wr, wa; if (r->method != NGX_HTTP_GET && r->method != NGX_HTTP_HEAD) { return NGX_HTTP_NOT_ALLOWED; } rc = ngx_http_discard_request_body(r); if (rc != NGX_OK) { return rc; } ngx_str_set(&r->headers_out.content_type, "text/plain"); if (r->method == NGX_HTTP_HEAD) { r->headers_out.status = NGX_HTTP_OK; rc = ngx_http_send_header(r); if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) { return rc; } } size = sizeof("Active connections: \n") + NGX_ATOMIC_T_LEN + sizeof("server accepts handled requests\n") - 1 + 6 + 3 * NGX_ATOMIC_T_LEN + sizeof("Reading: Writing: Waiting: \n") + 3 * NGX_ATOMIC_T_LEN; b = ngx_create_temp_buf(r->pool, size); if (b == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } out.buf = b; out.next = NULL; ap = *ngx_stat_accepted; hn = *ngx_stat_handled; ac = *ngx_stat_active; rq = *ngx_stat_requests; rd = *ngx_stat_reading; wr = *ngx_stat_writing; wa = *ngx_stat_waiting; b->last = ngx_sprintf(b->last, "Active connections: %uA \n", ac); b->last = ngx_cpymem(b->last, "server accepts handled requests\n", sizeof("server accepts handled requests\n") - 1); b->last = ngx_sprintf(b->last, " %uA %uA %uA \n", ap, hn, rq); b->last = ngx_sprintf(b->last, "Reading: %uA Writing: %uA Waiting: %uA \n", rd, wr, wa); r->headers_out.status = NGX_HTTP_OK; r->headers_out.content_length_n = b->last - b->pos; b->last_buf = (r == r->main) ? 1 : 0; b->last_in_chain = 1; rc = ngx_http_send_header(r); if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) { return rc; } return ngx_http_output_filter(r, &out); } static ngx_int_t ngx_http_stub_status_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { u_char *p; ngx_atomic_int_t value; p = ngx_pnalloc(r->pool, NGX_ATOMIC_T_LEN); if (p == NULL) { return NGX_ERROR; } switch (data) { case 0: value = *ngx_stat_active; break; case 1: value = *ngx_stat_reading; break; case 2: value = *ngx_stat_writing; break; case 3: value = *ngx_stat_waiting; break; /* suppress warning */ default: value = 0; break; } v->len = ngx_sprintf(p, "%uA", value) - p; v->valid = 1; v->no_cacheable = 0; v->not_found = 0; v->data = p; return NGX_OK; } static ngx_int_t ngx_http_stub_status_add_variables(ngx_conf_t *cf) { ngx_http_variable_t *var, *v; for (v = ngx_http_stub_status_vars; v->name.len; v++) { var = ngx_http_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 char *ngx_http_set_status(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_core_loc_conf_t *clcf; clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module); clcf->handler = ngx_http_status_handler; return NGX_CONF_OK; }