Mercurial > hg > nginx
view src/core/ngx_resolver.h @ 9270:3d455e37abf8
Core: PID file writing synchronization.
Now, ngx_daemon() does not call exit() in the parent process immediately,
but instead waits for the child process to signal it actually started (and
wrote the PID file if configured to). This ensures that the PID file
already exists when the parent process exits.
To make sure that signal handlers won't cause unexpected logging in the
parent process if the child process dies (for example, due to errors when
writing the PID file), ngx_init_signals() is moved to the child process.
This resolves "PID file ... not readable (yet?) after start" and "Failed
to parse PID from file..." errors as observed with systemd.
Note that the errors observed are considered to be a bug in systemd, which
isn't able to work properly with traditional Unix daemons. Still, the
workaround is implemented to make sure there will be no OS vendor patches
trying to address this.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 13 May 2024 06:13:22 +0300 |
parents | 2a77754cd9fe |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #ifndef _NGX_RESOLVER_H_INCLUDED_ #define _NGX_RESOLVER_H_INCLUDED_ #define NGX_RESOLVE_A 1 #define NGX_RESOLVE_CNAME 5 #define NGX_RESOLVE_PTR 12 #define NGX_RESOLVE_MX 15 #define NGX_RESOLVE_TXT 16 #if (NGX_HAVE_INET6) #define NGX_RESOLVE_AAAA 28 #endif #define NGX_RESOLVE_SRV 33 #define NGX_RESOLVE_DNAME 39 #define NGX_RESOLVE_FORMERR 1 #define NGX_RESOLVE_SERVFAIL 2 #define NGX_RESOLVE_NXDOMAIN 3 #define NGX_RESOLVE_NOTIMP 4 #define NGX_RESOLVE_REFUSED 5 #define NGX_RESOLVE_TIMEDOUT NGX_ETIMEDOUT #define NGX_NO_RESOLVER (void *) -1 #define NGX_RESOLVER_MAX_RECURSION 50 typedef struct ngx_resolver_s ngx_resolver_t; typedef struct { ngx_connection_t *udp; ngx_connection_t *tcp; struct sockaddr *sockaddr; socklen_t socklen; ngx_str_t server; ngx_log_t log; ngx_buf_t *read_buf; ngx_buf_t *write_buf; ngx_resolver_t *resolver; } ngx_resolver_connection_t; typedef struct ngx_resolver_ctx_s ngx_resolver_ctx_t; typedef void (*ngx_resolver_handler_pt)(ngx_resolver_ctx_t *ctx); typedef struct { struct sockaddr *sockaddr; socklen_t socklen; ngx_str_t name; u_short priority; u_short weight; } ngx_resolver_addr_t; typedef struct { ngx_str_t name; u_short priority; u_short weight; u_short port; } ngx_resolver_srv_t; typedef struct { ngx_str_t name; u_short priority; u_short weight; u_short port; ngx_resolver_ctx_t *ctx; ngx_int_t state; ngx_uint_t naddrs; ngx_addr_t *addrs; } ngx_resolver_srv_name_t; typedef struct { ngx_rbtree_node_t node; ngx_queue_t queue; /* PTR: resolved name, A: name to resolve */ u_char *name; #if (NGX_HAVE_INET6) /* PTR: IPv6 address to resolve (IPv4 address is in rbtree node key) */ struct in6_addr addr6; #endif u_short nlen; u_short qlen; u_char *query; #if (NGX_HAVE_INET6) u_char *query6; #endif union { in_addr_t addr; in_addr_t *addrs; u_char *cname; ngx_resolver_srv_t *srvs; } u; u_char code; u_short naddrs; u_short nsrvs; u_short cnlen; #if (NGX_HAVE_INET6) union { struct in6_addr addr6; struct in6_addr *addrs6; } u6; u_short naddrs6; #endif time_t expire; time_t valid; uint32_t ttl; unsigned tcp:1; #if (NGX_HAVE_INET6) unsigned tcp6:1; #endif ngx_uint_t last_connection; ngx_resolver_ctx_t *waiting; } ngx_resolver_node_t; struct ngx_resolver_s { /* has to be pointer because of "incomplete type" */ ngx_event_t *event; void *dummy; ngx_log_t *log; /* event ident must be after 3 pointers as in ngx_connection_t */ ngx_int_t ident; /* simple round robin DNS peers balancer */ ngx_array_t connections; ngx_uint_t last_connection; ngx_rbtree_t name_rbtree; ngx_rbtree_node_t name_sentinel; ngx_rbtree_t srv_rbtree; ngx_rbtree_node_t srv_sentinel; ngx_rbtree_t addr_rbtree; ngx_rbtree_node_t addr_sentinel; ngx_queue_t name_resend_queue; ngx_queue_t srv_resend_queue; ngx_queue_t addr_resend_queue; ngx_queue_t name_expire_queue; ngx_queue_t srv_expire_queue; ngx_queue_t addr_expire_queue; unsigned ipv4:1; #if (NGX_HAVE_INET6) unsigned ipv6:1; ngx_rbtree_t addr6_rbtree; ngx_rbtree_node_t addr6_sentinel; ngx_queue_t addr6_resend_queue; ngx_queue_t addr6_expire_queue; #endif time_t resend_timeout; time_t tcp_timeout; time_t expire; time_t valid; ngx_uint_t log_level; }; struct ngx_resolver_ctx_s { ngx_resolver_ctx_t *next; ngx_resolver_t *resolver; ngx_resolver_node_t *node; /* event ident must be after 3 pointers as in ngx_connection_t */ ngx_int_t ident; ngx_int_t state; ngx_str_t name; ngx_str_t service; time_t valid; ngx_uint_t naddrs; ngx_resolver_addr_t *addrs; ngx_resolver_addr_t addr; struct sockaddr_in sin; ngx_uint_t count; ngx_uint_t nsrvs; ngx_resolver_srv_name_t *srvs; ngx_resolver_handler_pt handler; void *data; ngx_msec_t timeout; unsigned quick:1; unsigned async:1; unsigned cancelable:1; ngx_uint_t recursion; ngx_event_t *event; }; ngx_resolver_t *ngx_resolver_create(ngx_conf_t *cf, ngx_str_t *names, ngx_uint_t n); ngx_resolver_ctx_t *ngx_resolve_start(ngx_resolver_t *r, ngx_resolver_ctx_t *temp); ngx_int_t ngx_resolve_name(ngx_resolver_ctx_t *ctx); void ngx_resolve_name_done(ngx_resolver_ctx_t *ctx); ngx_int_t ngx_resolve_addr(ngx_resolver_ctx_t *ctx); void ngx_resolve_addr_done(ngx_resolver_ctx_t *ctx); char *ngx_resolver_strerror(ngx_int_t err); #endif /* _NGX_RESOLVER_H_INCLUDED_ */