]> git.ipfire.org Git - thirdparty/haproxy.git/commitdiff
[MAJOR] frontend: split accept() into frontend_accept() and session_accept()
authorWilly Tarreau <w@1wt.eu>
Tue, 1 Jun 2010 15:45:26 +0000 (17:45 +0200)
committerWilly Tarreau <w@1wt.eu>
Mon, 14 Jun 2010 08:53:17 +0000 (10:53 +0200)
A new function session_accept() is now called from the lower layer to
instanciate a new session. Once the session is instanciated, the upper
layer's frontent_accept() is called. This one can be service-dependant.

That way, we have a 3-phase accept() sequence :
  1) protocol-specific, session-less accept(), which is pointed to by
     the listener. It defaults to the generic stream_sock_accept().
  2) session_accept() which relies on a frontend but not necessarily
     for use in a proxy (eg: stats or any future service).
  3) frontend_accept() which performs the accept for the service
     offerred by the frontend. It defaults to frontend_accept() which
     is really what is used by a proxy.

The TCP/HTTP proxies have been moved to this mode so that we can now rely on
frontend_accept() for any type of session initialization relying on a frontend.

The next step will be to convert the stats to use the same system for the stats.

include/proto/frontend.h
include/proto/session.h
src/cfgparse.c
src/frontend.c
src/session.c

index 61e0460eb5877a9da4db26979b8024c441d857dd..796ebbb4eab83d1c5e3e2840665c728f3a305ab2 100644 (file)
@@ -26,7 +26,7 @@
 #include <types/session.h>
 
 void get_frt_addr(struct session *s);
-int frontend_accept(struct listener *l, int cfd, struct sockaddr_storage *addr);
+int frontend_accept(struct session *s);
 
 
 #endif /* _PROTO_FRONTEND_H */
index 737e0650719fc9d7bfd86d8699d7ed75ac28c60b..c7a693e73755f9230bc0e5c8043e47158b20dde0 100644 (file)
@@ -1,23 +1,23 @@
 /*
-  include/proto/session.h
-  This file defines everything related to sessions.
-
 Copyright (C) 2000-2008 Willy Tarreau - w@1wt.eu
-
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public
-  License as published by the Free Software Foundation, version 2.1
-  exclusively.
-
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public
-  License along with this library; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
-*/
* include/proto/session.h
* This file defines everything related to sessions.
+ *
* Copyright (C) 2000-2010 Willy Tarreau - w@1wt.eu
+ *
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
+ *
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
* Lesser General Public License for more details.
+ *
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
 
 #ifndef _PROTO_SESSION_H
 #define _PROTO_SESSION_H
@@ -29,6 +29,7 @@
 extern struct pool_head *pool2_session;
 extern struct list sessions;
 
+int session_accept(struct listener *l, int cfd, struct sockaddr_storage *addr);
 void session_free(struct session *s);
 
 /* perform minimal intializations, report 0 in case of error, 1 if OK. */
index af27d9811f77bc47b52c34b1a3f810180b792713..1abb1b7137435cbab398ef5951ede55673cc103c 100644 (file)
@@ -5280,6 +5280,8 @@ out_uri_auth_compat:
                }
 
                if (curproxy->cap & PR_CAP_FE) {
+                       curproxy->accept = frontend_accept;
+
                        if (curproxy->tcp_req.inspect_delay ||
                            !LIST_ISEMPTY(&curproxy->tcp_req.inspect_rules))
                                curproxy->fe_req_ana |= AN_REQ_INSPECT;
@@ -5351,7 +5353,7 @@ out_uri_auth_compat:
                        listener->maxconn = curproxy->maxconn;
                        listener->backlog = curproxy->backlog;
                        listener->timeout = &curproxy->timeout.client;
-                       listener->accept = frontend_accept;
+                       listener->accept = session_accept;
                        listener->frontend = curproxy;
                        listener->handler = process_session;
                        listener->analysers |= curproxy->fe_req_ana;
index 0e4d24fa5989a21382380a98740784e57b5b63fb..d467e1408d99f6f65eafe277b45135e5da0f6bde 100644 (file)
@@ -53,200 +53,13 @@ void get_frt_addr(struct session *s)
        s->flags |= SN_FRT_ADDR_SET;
 }
 
-/* This function is called from the protocol layer accept() in order to instanciate
- * a new proxy. It returns a positive value upon success, 0 if the connection needs
- * to be closed and ignored, or a negative value upon critical failure.
+/* Finish a session accept() for a proxy (TCP or HTTP). It returns a negative
+ * value in case of failure, a positive value in case of success, or zero if
+ * it is a success but the session must be closed ASAP.
  */
-int frontend_accept(struct listener *l, int cfd, struct sockaddr_storage *addr)
+int frontend_accept(struct session *s)
 {
-       struct proxy *p = l->frontend;
-       struct session *s;
-       struct http_txn *txn;
-       struct task *t;
-
-       if (unlikely((s = pool_alloc2(pool2_session)) == NULL)) {
-               Alert("out of memory in event_accept().\n");
-               goto out_close;
-       }
-
-       /* minimum session initialization required for monitor mode below */
-       s->flags = 0;
-       s->logs.logwait = p->to_log;
-
-       /* if this session comes from a known monitoring system, we want to ignore
-        * it as soon as possible, which means closing it immediately for TCP, but
-        * cleanly.
-        */
-       if (unlikely((l->options & LI_O_CHK_MONNET) &&
-                    addr->ss_family == AF_INET &&
-                    (((struct sockaddr_in *)addr)->sin_addr.s_addr & p->mon_mask.s_addr) == p->mon_net.s_addr)) {
-               if (p->mode == PR_MODE_TCP) {
-                       pool_free2(pool2_session, s);
-                       return 0;
-               }
-               s->flags |= SN_MONITOR;
-               s->logs.logwait = 0;
-       }
-
-       /* OK, we're keeping the session, so let's properly initialize the session */
-       LIST_ADDQ(&sessions, &s->list);
-       LIST_INIT(&s->back_refs);
-
-       if (unlikely((t = task_new()) == NULL)) { /* disable this proxy for a while */
-               Alert("out of memory in event_accept().\n");
-               goto out_free_session;
-       }
-
-       s->term_trace = 0;
-       s->cli_addr = *addr;
-       s->logs.accept_date = date; /* user-visible date for logging */
-       s->logs.tv_accept = now;  /* corrected date for internal use */
-       s->uniq_id = totalconn;
-       proxy_inc_fe_ctr(l, p); /* note: cum_beconn will be increased once assigned */
-
-       t->process = l->handler;
-       t->context = s;
-       t->nice = l->nice;
-       t->expire = TICK_ETERNITY;
-
-       s->task = t;
-       s->listener = l;
-
-       /* Note: initially, the session's backend points to the frontend.
-        * This changes later when switching rules are executed or
-        * when the default backend is assigned.
-        */
-       s->be  = s->fe  = p;
-       s->req = s->rep = NULL; /* will be allocated later */
-
-       /* now evaluate the tcp-request layer4 rules. Since we expect to be able
-        * to abort right here as soon as possible, we check the rules before
-        * even initializing the stream interfaces.
-        */
-       if ((l->options & LI_O_TCP_RULES) && !tcp_exec_req_rules(s)) {
-               task_free(t);
-               LIST_DEL(&s->list);
-               pool_free2(pool2_session, s);
-               /* let's do a no-linger now to close with a single RST. */
-               setsockopt(cfd, SOL_SOCKET, SO_LINGER, (struct linger *) &nolinger, sizeof(struct linger));
-               return 0;
-       }
-
-       /* this part should be common with other protocols */
-       s->si[0].fd        = cfd;
-       s->si[0].owner     = t;
-       s->si[0].state     = s->si[0].prev_state = SI_ST_EST;
-       s->si[0].err_type  = SI_ET_NONE;
-       s->si[0].err_loc   = NULL;
-       s->si[0].connect   = NULL;
-       s->si[0].iohandler = NULL;
-       s->si[0].exp       = TICK_ETERNITY;
-       s->si[0].flags     = SI_FL_NONE;
-
-       if (likely(s->fe->options2 & PR_O2_INDEPSTR))
-               s->si[0].flags |= SI_FL_INDEP_STR;
-
-       if (addr->ss_family == AF_INET || addr->ss_family == AF_INET6)
-               s->si[0].flags = SI_FL_CAP_SPLTCP; /* TCP/TCPv6 splicing possible */
-
-       /* add the various callbacks */
-       stream_sock_prepare_interface(&s->si[0]);
-
-       /* pre-initialize the other side's stream interface to an INIT state. The
-        * callbacks will be initialized before attempting to connect.
-        */
-       s->si[1].fd        = -1; /* just to help with debugging */
-       s->si[1].owner     = t;
-       s->si[1].state     = s->si[1].prev_state = SI_ST_INI;
-       s->si[1].err_type  = SI_ET_NONE;
-       s->si[1].err_loc   = NULL;
-       s->si[1].connect   = NULL;
-       s->si[1].iohandler = NULL;
-       s->si[1].shutr     = stream_int_shutr;
-       s->si[1].shutw     = stream_int_shutw;
-       s->si[1].exp       = TICK_ETERNITY;
-       s->si[1].flags     = SI_FL_NONE;
-
-       if (likely(s->fe->options2 & PR_O2_INDEPSTR))
-               s->si[1].flags |= SI_FL_INDEP_STR;
-
-       s->srv = s->prev_srv = s->srv_conn = NULL;
-       s->pend_pos = NULL;
-
-       /* init store persistence */
-       s->store_count = 0;
-
-       /* Adjust some socket options */
-       if (unlikely(fcntl(cfd, F_SETFL, O_NONBLOCK) == -1)) {
-               Alert("accept(): cannot set the socket in non blocking mode. Giving up\n");
-               goto out_free_task;
-       }
-
-       txn = &s->txn;
-       /* Those variables will be checked and freed if non-NULL in
-        * session.c:session_free(). It is important that they are
-        * properly initialized.
-        */
-       txn->sessid = NULL;
-       txn->srv_cookie = NULL;
-       txn->cli_cookie = NULL;
-       txn->uri = NULL;
-       txn->req.cap = NULL;
-       txn->rsp.cap = NULL;
-       txn->hdr_idx.v = NULL;
-       txn->hdr_idx.size = txn->hdr_idx.used = 0;
-
-       if (unlikely((s->req = pool_alloc2(pool2_buffer)) == NULL))
-               goto out_free_task; /* no memory */
-
-       if (unlikely((s->rep = pool_alloc2(pool2_buffer)) == NULL))
-               goto out_free_req; /* no memory */
-
-       /* initialize the request buffer */
-       s->req->size = global.tune.bufsize;
-       buffer_init(s->req);
-       s->req->prod = &s->si[0];
-       s->req->cons = &s->si[1];
-       s->si[0].ib = s->si[1].ob = s->req;
-       s->req->flags |= BF_READ_ATTACHED; /* the producer is already connected */
-
-       /* activate default analysers enabled for this listener */
-       s->req->analysers = l->analysers;
-
-       s->req->wto = TICK_ETERNITY;
-       s->req->rto = TICK_ETERNITY;
-       s->req->rex = TICK_ETERNITY;
-       s->req->wex = TICK_ETERNITY;
-       s->req->analyse_exp = TICK_ETERNITY;
-
-       /* initialize response buffer */
-       s->rep->size = global.tune.bufsize;
-       buffer_init(s->rep);
-       s->rep->prod = &s->si[1];
-       s->rep->cons = &s->si[0];
-       s->si[0].ob = s->si[1].ib = s->rep;
-       s->rep->analysers = 0;
-
-       s->rep->rto = TICK_ETERNITY;
-       s->rep->wto = TICK_ETERNITY;
-       s->rep->rex = TICK_ETERNITY;
-       s->rep->wex = TICK_ETERNITY;
-       s->rep->analyse_exp = TICK_ETERNITY;
-
-       /* finish initialization of the accepted file descriptor */
-       fd_insert(cfd);
-       fdtab[cfd].owner = &s->si[0];
-       fdtab[cfd].state = FD_STREADY;
-       fdtab[cfd].flags = 0;
-       fdtab[cfd].cb[DIR_RD].f = l->proto->read;
-       fdtab[cfd].cb[DIR_RD].b = s->req;
-       fdtab[cfd].cb[DIR_WR].f = l->proto->write;
-       fdtab[cfd].cb[DIR_WR].b = s->rep;
-       fdinfo[cfd].peeraddr = (struct sockaddr *)&s->cli_addr;
-       fdinfo[cfd].peerlen  = sizeof(s->cli_addr);
-       EV_FD_SET(cfd, DIR_RD);
-
-       /***************** to be moved to the TCP/HTTP frontend's accept() **************/
+       int cfd = s->si[0].fd;
 
        tv_zero(&s->logs.tv_request);
        s->logs.t_queue = -1;
@@ -277,10 +90,10 @@ int frontend_accept(struct listener *l, int cfd, struct sockaddr_storage *addr)
                goto out_delete_cfd;
        }
 
-       if (p->options & PR_O_TCP_CLI_KA)
+       if (s->fe->options & PR_O_TCP_CLI_KA)
                setsockopt(cfd, SOL_SOCKET, SO_KEEPALIVE, (char *) &one, sizeof(one));
 
-       if (p->options & PR_O_TCP_NOLING)
+       if (s->fe->options & PR_O_TCP_NOLING)
                setsockopt(cfd, SOL_SOCKET, SO_LINGER, (struct linger *) &nolinger, sizeof(struct linger));
 
        if (global.tune.client_sndbuf)
@@ -289,34 +102,34 @@ int frontend_accept(struct listener *l, int cfd, struct sockaddr_storage *addr)
        if (global.tune.client_rcvbuf)
                setsockopt(cfd, SOL_SOCKET, SO_RCVBUF, &global.tune.client_rcvbuf, sizeof(global.tune.client_rcvbuf));
 
-       if (p->mode == PR_MODE_HTTP) {
+       if (s->fe->mode == PR_MODE_HTTP) {
                /* the captures are only used in HTTP frontends */
-               if (unlikely(p->nb_req_cap > 0 &&
-                            (txn->req.cap = pool_alloc2(p->req_cap_pool)) == NULL))
+               if (unlikely(s->fe->nb_req_cap > 0 &&
+                            (s->txn.req.cap = pool_alloc2(s->fe->req_cap_pool)) == NULL))
                        goto out_delete_cfd;    /* no memory */
 
-               if (unlikely(p->nb_rsp_cap > 0 &&
-                            (txn->rsp.cap = pool_alloc2(p->rsp_cap_pool)) == NULL))
+               if (unlikely(s->fe->nb_rsp_cap > 0 &&
+                            (s->txn.rsp.cap = pool_alloc2(s->fe->rsp_cap_pool)) == NULL))
                        goto out_free_reqcap;   /* no memory */
        }
 
-       if (p->acl_requires & ACL_USE_L7_ANY) {
+       if (s->fe->acl_requires & ACL_USE_L7_ANY) {
                /* we have to allocate header indexes only if we know
                 * that we may make use of them. This of course includes
                 * (mode == PR_MODE_HTTP).
                 */
-               txn->hdr_idx.size = MAX_HTTP_HDR;
+               s->txn.hdr_idx.size = MAX_HTTP_HDR;
 
-               if (unlikely((txn->hdr_idx.v = pool_alloc2(p->hdr_idx_pool)) == NULL))
+               if (unlikely((s->txn.hdr_idx.v = pool_alloc2(s->fe->hdr_idx_pool)) == NULL))
                        goto out_free_rspcap; /* no memory */
 
                /* and now initialize the HTTP transaction state */
                http_init_txn(s);
        }
 
-       if ((p->mode == PR_MODE_TCP || p->mode == PR_MODE_HTTP)
-           && (p->logfac1 >= 0 || p->logfac2 >= 0)) {
-               if (likely(p->to_log)) {
+       if ((s->fe->mode == PR_MODE_TCP || s->fe->mode == PR_MODE_HTTP)
+           && (s->fe->logfac1 >= 0 || s->fe->logfac2 >= 0)) {
+               if (likely(s->fe->to_log)) {
                        /* we have the client ip */
                        if (s->logs.logwait & LW_CLIP)
                                if (!(s->logs.logwait &= ~LW_CLIP))
@@ -332,10 +145,10 @@ int frontend_accept(struct listener *l, int cfd, struct sockaddr_storage *addr)
                                      sn, sizeof(sn)) &&
                            inet_ntop(AF_INET, (const void *)&((struct sockaddr_in *)&s->cli_addr)->sin_addr,
                                      pn, sizeof(pn))) {
-                               send_log(p, LOG_INFO, "Connect from %s:%d to %s:%d (%s/%s)\n",
+                               send_log(s->fe, LOG_INFO, "Connect from %s:%d to %s:%d (%s/%s)\n",
                                         pn, ntohs(((struct sockaddr_in *)&s->cli_addr)->sin_port),
                                         sn, ntohs(((struct sockaddr_in *)&s->frt_addr)->sin_port),
-                                        p->id, (p->mode == PR_MODE_HTTP) ? "HTTP" : "TCP");
+                                        s->fe->id, (s->fe->mode == PR_MODE_HTTP) ? "HTTP" : "TCP");
                        }
                }
                else {
@@ -348,10 +161,10 @@ int frontend_accept(struct listener *l, int cfd, struct sockaddr_storage *addr)
                                      sn, sizeof(sn)) &&
                            inet_ntop(AF_INET6, (const void *)&((struct sockaddr_in6 *)&s->cli_addr)->sin6_addr,
                                      pn, sizeof(pn))) {
-                               send_log(p, LOG_INFO, "Connect from %s:%d to %s:%d (%s/%s)\n",
+                               send_log(s->fe, LOG_INFO, "Connect from %s:%d to %s:%d (%s/%s)\n",
                                         pn, ntohs(((struct sockaddr_in6 *)&s->cli_addr)->sin6_port),
                                         sn, ntohs(((struct sockaddr_in6 *)&s->frt_addr)->sin6_port),
-                                        p->id, (p->mode == PR_MODE_HTTP) ? "HTTP" : "TCP");
+                                        s->fe->id, (s->fe->mode == PR_MODE_HTTP) ? "HTTP" : "TCP");
                        }
                }
        }
@@ -369,7 +182,7 @@ int frontend_accept(struct listener *l, int cfd, struct sockaddr_storage *addr)
                                  pn, sizeof(pn));
 
                        len = sprintf(trash, "%08x:%s.accept(%04x)=%04x from [%s:%d]\n",
-                                     s->uniq_id, p->id, (unsigned short)l->fd, (unsigned short)cfd,
+                                     s->uniq_id, s->fe->id, (unsigned short)s->listener->fd, (unsigned short)cfd,
                                      pn, ntohs(((struct sockaddr_in *)&s->cli_addr)->sin_port));
                }
                else {
@@ -379,14 +192,14 @@ int frontend_accept(struct listener *l, int cfd, struct sockaddr_storage *addr)
                                  pn, sizeof(pn));
 
                        len = sprintf(trash, "%08x:%s.accept(%04x)=%04x from [%s:%d]\n",
-                                     s->uniq_id, p->id, (unsigned short)l->fd, (unsigned short)cfd,
+                                     s->uniq_id, s->fe->id, (unsigned short)s->listener->fd, (unsigned short)cfd,
                                      pn, ntohs(((struct sockaddr_in6 *)(&s->cli_addr))->sin6_port));
                }
 
                write(1, trash, len);
        }
 
-       if (p->mode == PR_MODE_HTTP)
+       if (s->fe->mode == PR_MODE_HTTP)
                s->req->flags |= BF_READ_DONTWAIT; /* one read is usually enough */
 
        /* note: this should not happen anymore since there's always at least the switching rules */
@@ -399,11 +212,11 @@ int frontend_accept(struct listener *l, int cfd, struct sockaddr_storage *addr)
        s->rep->wto = s->fe->timeout.client;
 
        fdtab[cfd].flags = FD_FL_TCP | FD_FL_TCP_NODELAY;
-       if (p->options & PR_O_TCP_NOLING)
+       if (s->fe->options & PR_O_TCP_NOLING)
                fdtab[cfd].flags |= FD_FL_TCP_NOLING;
 
-       if (unlikely((p->mode == PR_MODE_HTTP && (s->flags & SN_MONITOR)) ||
-                    (p->mode == PR_MODE_HEALTH && (p->options & PR_O_HTTP_CHK)))) {
+       if (unlikely((s->fe->mode == PR_MODE_HTTP && (s->flags & SN_MONITOR)) ||
+                    (s->fe->mode == PR_MODE_HEALTH && (s->fe->options & PR_O_HTTP_CHK)))) {
                /* Either we got a request from a monitoring system on an HTTP instance,
                 * or we're in health check mode with the 'httpchk' option enabled. In
                 * both cases, we return a fake "HTTP/1.0 200 OK" response and we exit.
@@ -412,44 +225,27 @@ int frontend_accept(struct listener *l, int cfd, struct sockaddr_storage *addr)
                chunk_initstr(&msg, "HTTP/1.0 200 OK\r\n\r\n");
                stream_int_retnclose(&s->si[0], &msg); /* forge a 200 response */
                s->req->analysers = 0;
-               t->expire = s->rep->wex;
+               s->task->expire = s->rep->wex;
                EV_FD_CLR(cfd, DIR_RD);
        }
-       else if (unlikely(p->mode == PR_MODE_HEALTH)) {  /* health check mode, no client reading */
+       else if (unlikely(s->fe->mode == PR_MODE_HEALTH)) {  /* health check mode, no client reading */
                struct chunk msg;
                chunk_initstr(&msg, "OK\n");
                stream_int_retnclose(&s->si[0], &msg); /* forge an "OK" response */
                s->req->analysers = 0;
-               t->expire = s->rep->wex;
+               s->task->expire = s->rep->wex;
                EV_FD_CLR(cfd, DIR_RD);
        }
-
-       /**********************************************/
-
-       /* it is important not to call the wakeup function directly but to
-        * pass through task_wakeup(), because this one knows how to apply
-        * priorities to tasks.
-        */
-       task_wakeup(t, TASK_WOKEN_INIT);
-
+       /* everything's OK, let's go on */
        return 1;
 
        /* Error unrolling */
  out_free_rspcap:
-       pool_free2(p->rsp_cap_pool, txn->rsp.cap);
+       pool_free2(s->fe->rsp_cap_pool, s->txn.rsp.cap);
  out_free_reqcap:
-       pool_free2(p->req_cap_pool, txn->req.cap);
+       pool_free2(s->fe->req_cap_pool, s->txn.req.cap);
  out_delete_cfd:
        fd_delete(cfd);
-       pool_free2(pool2_buffer, s->rep);
- out_free_req:
-       pool_free2(pool2_buffer, s->req);
- out_free_task:
-       task_free(t);
- out_free_session:
-       LIST_DEL(&s->list);
-       pool_free2(pool2_session, s);
- out_close:
        return -1;
 }
 
index 631744236383e2ab2b8c6fcb73f75a3f927c3658..0ccd9959dfdeedf0a77f7a8adf99c885c01f4302 100644 (file)
@@ -1,7 +1,7 @@
 /*
- * Server management functions.
+ * Session management functions.
  *
- * Copyright 2000-2008 Willy Tarreau <w@1wt.eu>
+ * Copyright 2000-2010 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -11,6 +11,8 @@
  */
 
 #include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
 
 #include <common/config.h>
 #include <common/debug.h>
 struct pool_head *pool2_session;
 struct list sessions;
 
+/* This function is called from the protocol layer accept() in order to instanciate
+ * a new session on behalf of a given listener and frontend. It returns a positive
+ * value upon success, 0 if the connection needs to be closed and ignored, or a
+ * negative value upon critical failure.
+ */
+int session_accept(struct listener *l, int cfd, struct sockaddr_storage *addr)
+{
+       struct proxy *p = l->frontend;
+       struct session *s;
+       struct http_txn *txn;
+       struct task *t;
+
+       if (unlikely((s = pool_alloc2(pool2_session)) == NULL)) {
+               Alert("out of memory in event_accept().\n");
+               goto out_close;
+       }
+
+       /* minimum session initialization required for monitor mode below */
+       s->flags = 0;
+       s->logs.logwait = p->to_log;
+
+       /* if this session comes from a known monitoring system, we want to ignore
+        * it as soon as possible, which means closing it immediately for TCP, but
+        * cleanly.
+        */
+       if (unlikely((l->options & LI_O_CHK_MONNET) &&
+                    addr->ss_family == AF_INET &&
+                    (((struct sockaddr_in *)addr)->sin_addr.s_addr & p->mon_mask.s_addr) == p->mon_net.s_addr)) {
+               if (p->mode == PR_MODE_TCP) {
+                       pool_free2(pool2_session, s);
+                       return 0;
+               }
+               s->flags |= SN_MONITOR;
+               s->logs.logwait = 0;
+       }
+
+       /* OK, we're keeping the session, so let's properly initialize the session */
+       LIST_ADDQ(&sessions, &s->list);
+       LIST_INIT(&s->back_refs);
+
+       if (unlikely((t = task_new()) == NULL)) { /* disable this proxy for a while */
+               Alert("out of memory in event_accept().\n");
+               goto out_free_session;
+       }
+
+       s->term_trace = 0;
+       s->cli_addr = *addr;
+       s->logs.accept_date = date; /* user-visible date for logging */
+       s->logs.tv_accept = now;  /* corrected date for internal use */
+       s->uniq_id = totalconn;
+       proxy_inc_fe_ctr(l, p); /* note: cum_beconn will be increased once assigned */
+
+       t->process = l->handler;
+       t->context = s;
+       t->nice = l->nice;
+       t->expire = TICK_ETERNITY;
+
+       s->task = t;
+       s->listener = l;
+
+       /* Note: initially, the session's backend points to the frontend.
+        * This changes later when switching rules are executed or
+        * when the default backend is assigned.
+        */
+       s->be  = s->fe  = p;
+       s->req = s->rep = NULL; /* will be allocated later */
+
+       /* now evaluate the tcp-request layer4 rules. Since we expect to be able
+        * to abort right here as soon as possible, we check the rules before
+        * even initializing the stream interfaces.
+        */
+       if ((l->options & LI_O_TCP_RULES) && !tcp_exec_req_rules(s)) {
+               task_free(t);
+               LIST_DEL(&s->list);
+               pool_free2(pool2_session, s);
+               /* let's do a no-linger now to close with a single RST. */
+               setsockopt(cfd, SOL_SOCKET, SO_LINGER, (struct linger *) &nolinger, sizeof(struct linger));
+               return 0;
+       }
+
+       /* this part should be common with other protocols */
+       s->si[0].fd        = cfd;
+       s->si[0].owner     = t;
+       s->si[0].state     = s->si[0].prev_state = SI_ST_EST;
+       s->si[0].err_type  = SI_ET_NONE;
+       s->si[0].err_loc   = NULL;
+       s->si[0].connect   = NULL;
+       s->si[0].iohandler = NULL;
+       s->si[0].exp       = TICK_ETERNITY;
+       s->si[0].flags     = SI_FL_NONE;
+
+       if (likely(s->fe->options2 & PR_O2_INDEPSTR))
+               s->si[0].flags |= SI_FL_INDEP_STR;
+
+       if (addr->ss_family == AF_INET || addr->ss_family == AF_INET6)
+               s->si[0].flags = SI_FL_CAP_SPLTCP; /* TCP/TCPv6 splicing possible */
+
+       /* add the various callbacks */
+       stream_sock_prepare_interface(&s->si[0]);
+
+       /* pre-initialize the other side's stream interface to an INIT state. The
+        * callbacks will be initialized before attempting to connect.
+        */
+       s->si[1].fd        = -1; /* just to help with debugging */
+       s->si[1].owner     = t;
+       s->si[1].state     = s->si[1].prev_state = SI_ST_INI;
+       s->si[1].err_type  = SI_ET_NONE;
+       s->si[1].err_loc   = NULL;
+       s->si[1].connect   = NULL;
+       s->si[1].iohandler = NULL;
+       s->si[1].shutr     = stream_int_shutr;
+       s->si[1].shutw     = stream_int_shutw;
+       s->si[1].exp       = TICK_ETERNITY;
+       s->si[1].flags     = SI_FL_NONE;
+
+       if (likely(s->fe->options2 & PR_O2_INDEPSTR))
+               s->si[1].flags |= SI_FL_INDEP_STR;
+
+       s->srv = s->prev_srv = s->srv_conn = NULL;
+       s->pend_pos = NULL;
+
+       /* init store persistence */
+       s->store_count = 0;
+
+       /* Adjust some socket options */
+       if (unlikely(fcntl(cfd, F_SETFL, O_NONBLOCK) == -1)) {
+               Alert("accept(): cannot set the socket in non blocking mode. Giving up\n");
+               goto out_free_task;
+       }
+
+       txn = &s->txn;
+       /* Those variables will be checked and freed if non-NULL in
+        * session.c:session_free(). It is important that they are
+        * properly initialized.
+        */
+       txn->sessid = NULL;
+       txn->srv_cookie = NULL;
+       txn->cli_cookie = NULL;
+       txn->uri = NULL;
+       txn->req.cap = NULL;
+       txn->rsp.cap = NULL;
+       txn->hdr_idx.v = NULL;
+       txn->hdr_idx.size = txn->hdr_idx.used = 0;
+
+       if (unlikely((s->req = pool_alloc2(pool2_buffer)) == NULL))
+               goto out_free_task; /* no memory */
+
+       if (unlikely((s->rep = pool_alloc2(pool2_buffer)) == NULL))
+               goto out_free_req; /* no memory */
+
+       /* initialize the request buffer */
+       s->req->size = global.tune.bufsize;
+       buffer_init(s->req);
+       s->req->prod = &s->si[0];
+       s->req->cons = &s->si[1];
+       s->si[0].ib = s->si[1].ob = s->req;
+       s->req->flags |= BF_READ_ATTACHED; /* the producer is already connected */
+
+       /* activate default analysers enabled for this listener */
+       s->req->analysers = l->analysers;
+
+       s->req->wto = TICK_ETERNITY;
+       s->req->rto = TICK_ETERNITY;
+       s->req->rex = TICK_ETERNITY;
+       s->req->wex = TICK_ETERNITY;
+       s->req->analyse_exp = TICK_ETERNITY;
+
+       /* initialize response buffer */
+       s->rep->size = global.tune.bufsize;
+       buffer_init(s->rep);
+       s->rep->prod = &s->si[1];
+       s->rep->cons = &s->si[0];
+       s->si[0].ob = s->si[1].ib = s->rep;
+       s->rep->analysers = 0;
+
+       s->rep->rto = TICK_ETERNITY;
+       s->rep->wto = TICK_ETERNITY;
+       s->rep->rex = TICK_ETERNITY;
+       s->rep->wex = TICK_ETERNITY;
+       s->rep->analyse_exp = TICK_ETERNITY;
+
+       /* finish initialization of the accepted file descriptor */
+       fd_insert(cfd);
+       fdtab[cfd].owner = &s->si[0];
+       fdtab[cfd].state = FD_STREADY;
+       fdtab[cfd].flags = 0;
+       fdtab[cfd].cb[DIR_RD].f = l->proto->read;
+       fdtab[cfd].cb[DIR_RD].b = s->req;
+       fdtab[cfd].cb[DIR_WR].f = l->proto->write;
+       fdtab[cfd].cb[DIR_WR].b = s->rep;
+       fdinfo[cfd].peeraddr = (struct sockaddr *)&s->cli_addr;
+       fdinfo[cfd].peerlen  = sizeof(s->cli_addr);
+       EV_FD_SET(cfd, DIR_RD);
+
+       if (p->accept) {
+               int ret = p->accept(s);
+               if (unlikely(ret < 0))
+                       goto out_free_rep;
+
+               if (unlikely(ret == 0)) {
+                       /* work is finished, we can release everything (eg: monitoring) */
+                       pool_free2(pool2_buffer, s->rep);
+                       pool_free2(pool2_buffer, s->req);
+                       task_free(t);
+                       LIST_DEL(&s->list);
+                       pool_free2(pool2_session, s);
+                       return 0;
+               }
+       }
+
+       /* it is important not to call the wakeup function directly but to
+        * pass through task_wakeup(), because this one knows how to apply
+        * priorities to tasks.
+        */
+       task_wakeup(t, TASK_WOKEN_INIT);
+       return 1;
+
+       /* Error unrolling */
+ out_free_rep:
+       pool_free2(pool2_buffer, s->rep);
+ out_free_req:
+       pool_free2(pool2_buffer, s->req);
+ out_free_task:
+       task_free(t);
+ out_free_session:
+       LIST_DEL(&s->list);
+       pool_free2(pool2_session, s);
+ out_close:
+       return -1;
+}
+
 /*
  * frees  the context associated to a session. It must have been removed first.
  */