Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commitf3868f8

Browse files
committed
A bit of code beautification/cleanup of obsolete comments. Rethink
ordering of startup operations in one or two places.
1 parent90e2663 commitf3868f8

File tree

1 file changed

+64
-48
lines changed

1 file changed

+64
-48
lines changed

‎src/backend/postmaster/postmaster.c‎

Lines changed: 64 additions & 48 deletions
Original file line numberDiff line numberDiff line change
@@ -22,13 +22,22 @@
2222
* if it did much with shared memory then it would be prone to crashing
2323
* along with the backends.
2424
*
25+
* When a request message is received, we now fork() immediately.
26+
* The child process performs authentication of the request, and
27+
* then becomes a backend if successful. This allows the auth code
28+
* to be written in a simple single-threaded style (as opposed to the
29+
* crufty "poor man's multitasking" code that used to be needed).
30+
* More importantly, it ensures that blockages in non-multithreaded
31+
* libraries like SSL or PAM cannot cause denial of service to other
32+
* clients.
33+
*
2534
*
2635
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
2736
* Portions Copyright (c) 1994, Regents of the University of California
2837
*
2938
*
3039
* IDENTIFICATION
31-
* $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.224 2001/06/20 18:07:55 petere Exp $
40+
* $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.225 2001/06/21 16:43:24 tgl Exp $
3241
*
3342
* NOTES
3443
*
@@ -102,25 +111,23 @@
102111
#ifdefHAVE_SIGPROCMASK
103112
sigset_tUnBlockSig,
104113
BlockSig;
105-
106114
#else
107115
intUnBlockSig,
108116
BlockSig;
109-
110117
#endif
111118

112119
/*
113-
* Info for garbage collection. Whenever a process dies, the Postmaster
114-
* cleans up after it.Currently, NO information is required for cleanup,
115-
* but I left this structure around in case that changed.
120+
* List of active backends (or child processes anyway; we don't actually
121+
* know whether a given child has become a backend or is still in the
122+
* authorization phase). This is used mainly to keep track of how many
123+
* children we have and send them appropriate signals when necessary.
116124
*/
117125
typedefstructbkend
118126
{
119127
pid_tpid;/* process id of backend */
120128
longcancel_key;/* cancel key for cancels for this backend */
121129
}Backend;
122130

123-
/* list of active backends. For garbage collection only now. */
124131
staticDllist*BackendList;
125132

126133
/* The socket number we are listening for connections on */
@@ -155,12 +162,10 @@ static intServerSock_INET = INVALID_SOCK;/* stream socket server */
155162

156163
#ifdefHAVE_UNIX_SOCKETS
157164
staticintServerSock_UNIX=INVALID_SOCK;/* stream socket server */
158-
159165
#endif
160166

161167
#ifdefUSE_SSL
162168
staticSSL_CTX*SSL_context=NULL;/* Global SSL context */
163-
164169
#endif
165170

166171
/*
@@ -178,12 +183,14 @@ static char ExtraOptions[MAXPGPATH];
178183
staticboolReinit= true;
179184
staticintSendStop= false;
180185

186+
/* still more option variables */
181187
boolNetServer= false;/* listen on TCP/IP */
182188
boolEnableSSL= false;
183189
boolSilentMode= false;/* silent mode (-S) */
184190

185191
intCheckPointTimeout=300;
186192

193+
/* Startup/shutdown state */
187194
staticpid_tStartupPID=0,
188195
ShutdownPID=0,
189196
CheckPointPID=0;
@@ -230,7 +237,7 @@ static void ExitPostmaster(int status);
230237
staticvoidusage(constchar*);
231238
staticintServerLoop(void);
232239
staticintBackendStartup(Port*port);
233-
staticintProcessStartupPacket(Port*port);
240+
staticintProcessStartupPacket(Port*port,boolSSLdone);
234241
staticvoidprocessCancelRequest(Port*port,void*pkt);
235242
staticintinitMasks(fd_set*rmask,fd_set*wmask);
236243
staticchar*canAcceptConnections(void);
@@ -579,6 +586,20 @@ PostmasterMain(int argc, char *argv[])
579586
fprintf(stderr,"-----------------------------------------\n");
580587
}
581588

589+
/*
590+
* Initialize SSL library, if specified.
591+
*/
592+
#ifdefUSE_SSL
593+
if (EnableSSL&& !NetServer)
594+
{
595+
postmaster_error("For SSL, TCP/IP connections must be enabled.");
596+
fprintf(stderr,gettext("Try '%s --help' for more information.\n"),progname);
597+
ExitPostmaster(1);
598+
}
599+
if (EnableSSL)
600+
InitSSL();
601+
#endif
602+
582603
/*
583604
* Fork away from controlling terminal, if -S specified.
584605
*
@@ -609,17 +630,6 @@ PostmasterMain(int argc, char *argv[])
609630
/*
610631
* Establish input sockets.
611632
*/
612-
#ifdefUSE_SSL
613-
if (EnableSSL&& !NetServer)
614-
{
615-
postmaster_error("For SSL, TCP/IP connections must be enabled.");
616-
fprintf(stderr,gettext("Try '%s --help' for more information.\n"),progname);
617-
ExitPostmaster(1);
618-
}
619-
if (EnableSSL)
620-
InitSSL();
621-
#endif
622-
623633
if (NetServer)
624634
{
625635
status=StreamServerPort(AF_INET,VirtualHost,
@@ -653,8 +663,7 @@ PostmasterMain(int argc, char *argv[])
653663
reset_shared(PostPortNumber);
654664

655665
/*
656-
* Initialize the list of active backends.This list is only used for
657-
* garbage collecting the backend processes.
666+
* Initialize the list of active backends.
658667
*/
659668
BackendList=DLNewList();
660669

@@ -811,7 +820,6 @@ ServerLoop(void)
811820

812821
if (CheckPointTimeout+checkpointed>now)
813822
{
814-
815823
/*
816824
* Not time for checkpoint yet, so set a timeout for
817825
* select
@@ -883,7 +891,8 @@ ServerLoop(void)
883891
}
884892

885893
/*
886-
* new connection pending on our well-known port's socket?
894+
* New connection pending on our well-known port's socket?
895+
* If so, fork a child process to deal with it.
887896
*/
888897

889898
#ifdefHAVE_UNIX_SOCKETS
@@ -892,9 +901,15 @@ ServerLoop(void)
892901
{
893902
port=ConnCreate(ServerSock_UNIX);
894903
if (port)
904+
{
895905
BackendStartup(port);
896-
StreamClose(port->sock);
897-
ConnFree(port);
906+
/*
907+
* We no longer need the open socket or port structure
908+
* in this process
909+
*/
910+
StreamClose(port->sock);
911+
ConnFree(port);
912+
}
898913
}
899914
#endif
900915

@@ -903,9 +918,15 @@ ServerLoop(void)
903918
{
904919
port=ConnCreate(ServerSock_INET);
905920
if (port)
921+
{
906922
BackendStartup(port);
907-
StreamClose(port->sock);
908-
ConnFree(port);
923+
/*
924+
* We no longer need the open socket or port structure
925+
* in this process
926+
*/
927+
StreamClose(port->sock);
928+
ConnFree(port);
929+
}
909930
}
910931
}
911932
}
@@ -952,7 +973,7 @@ initMasks(fd_set *rmask, fd_set *wmask)
952973
* not return at all.
953974
*/
954975
staticint
955-
ProcessStartupPacket(Port*port)
976+
ProcessStartupPacket(Port*port,boolSSLdone)
956977
{
957978
StartupPacket*packet;
958979
char*rejectMsg;
@@ -983,7 +1004,7 @@ ProcessStartupPacket(Port *port)
9831004
return127;/* XXX */
9841005
}
9851006

986-
if (port->proto==NEGOTIATE_SSL_CODE)
1007+
if (port->proto==NEGOTIATE_SSL_CODE&& !SSLdone)
9871008
{
9881009
charSSLok;
9891010

@@ -1016,10 +1037,9 @@ ProcessStartupPacket(Port *port)
10161037
}
10171038
}
10181039
#endif
1019-
/* regular startup packet should follow... */
1020-
/* FIXME: by continuing to send SSL negotiation packets, a
1021-
client could run us out of stack space */
1022-
returnProcessStartupPacket(port);
1040+
/* regular startup packet, cancel, etc packet should follow... */
1041+
/* but not another SSL negotiation request */
1042+
returnProcessStartupPacket(port, true);
10231043
}
10241044

10251045
/* Could add additional special packet types here */
@@ -1211,11 +1231,8 @@ ConnFree(Port *conn)
12111231
* ClosePostmasterPorts -- close all the postmaster's open sockets
12121232
*
12131233
* This is called during child process startup to release file descriptors
1214-
* that are not needed by that child process.
1215-
*
1216-
* Note that closing the child's descriptor does not destroy the client
1217-
* connection prematurely, since the parent (postmaster) process still
1218-
* has the socket open.
1234+
* that are not needed by that child process. The postmaster still has
1235+
* them open, of course.
12191236
*/
12201237
staticvoid
12211238
ClosePostmasterPorts(void)
@@ -1685,9 +1702,7 @@ SignalChildren(int signal)
16851702
/*
16861703
* BackendStartup -- start backend process
16871704
*
1688-
* returns: STATUS_ERROR if the fork/exec failed, STATUS_OK
1689-
*otherwise.
1690-
*
1705+
* returns: STATUS_ERROR if the fork/exec failed, STATUS_OK otherwise.
16911706
*/
16921707
staticint
16931708
BackendStartup(Port*port)
@@ -1814,7 +1829,8 @@ split_opts(char **argv, int *argcp, char *s)
18141829
}
18151830

18161831
/*
1817-
* DoBackend -- set up the backend's argument list and invoke backend main().
1832+
* DoBackend -- perform authentication, and if successful, set up the
1833+
*backend's argument list and invoke backend main().
18181834
*
18191835
* This used to perform an execv() but we no longer exec the backend;
18201836
* it's the same executable as the postmaster.
@@ -1849,6 +1865,9 @@ DoBackend(Port *port)
18491865
* Signal handlers setting is moved to tcop/postgres...
18501866
*/
18511867

1868+
/* Close the postmaster's other sockets */
1869+
ClosePostmasterPorts();
1870+
18521871
SetProcessingMode(InitProcessing);
18531872

18541873
/* Save port etc. for ps status */
@@ -1859,13 +1878,10 @@ DoBackend(Port *port)
18591878

18601879
whereToSendOutput=Remote;
18611880

1862-
status=ProcessStartupPacket(port);
1881+
status=ProcessStartupPacket(port, false);
18631882
if (status==127)
18641883
return0;/* cancel request processed */
18651884

1866-
/* Close the postmaster's other sockets */
1867-
ClosePostmasterPorts();
1868-
18691885
/*
18701886
* Don't want backend to be able to see the postmaster random number
18711887
* generator state. We have to clobber the static random_seed *and*

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp