postgresql/src/backend/libpq/be-secure.c

298 lines
6.3 KiB
C

/*-------------------------------------------------------------------------
*
* be-secure.c
* functions related to setting up a secure connection to the frontend.
* Secure connections are expected to provide confidentiality,
* message integrity and endpoint authentication.
*
*
* Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/libpq/be-secure.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <sys/stat.h>
#include <signal.h>
#include <fcntl.h>
#include <ctype.h>
#include <sys/socket.h>
#include <unistd.h>
#include <netdb.h>
#include <netinet/in.h>
#ifdef HAVE_NETINET_TCP_H
#include <netinet/tcp.h>
#include <arpa/inet.h>
#endif
#include "libpq/libpq.h"
#include "miscadmin.h"
#include "tcop/tcopprot.h"
#include "utils/memutils.h"
#include "storage/ipc.h"
#include "storage/proc.h"
char *ssl_cert_file;
char *ssl_key_file;
char *ssl_ca_file;
char *ssl_crl_file;
#ifdef USE_SSL
bool ssl_loaded_verify_locations = false;
#endif
/* GUC variable controlling SSL cipher list */
char *SSLCipherSuites = NULL;
/* GUC variable for default ECHD curve. */
char *SSLECDHCurve;
/* GUC variable: if false, prefer client ciphers */
bool SSLPreferServerCiphers;
/* ------------------------------------------------------------ */
/* Procedures common to all secure sessions */
/* ------------------------------------------------------------ */
/*
* Initialize global context
*/
int
secure_initialize(void)
{
#ifdef USE_SSL
be_tls_init();
#endif
return 0;
}
/*
* Indicate if we have loaded the root CA store to verify certificates
*/
bool
secure_loaded_verify_locations(void)
{
#ifdef USE_SSL
return ssl_loaded_verify_locations;
#else
return false;
#endif
}
/*
* Attempt to negotiate secure session.
*/
int
secure_open_server(Port *port)
{
int r = 0;
#ifdef USE_SSL
r = be_tls_open_server(port);
#endif
return r;
}
/*
* Close secure session.
*/
void
secure_close(Port *port)
{
#ifdef USE_SSL
if (port->ssl_in_use)
be_tls_close(port);
#endif
}
/*
* Read data from a secure connection.
*/
ssize_t
secure_read(Port *port, void *ptr, size_t len)
{
ssize_t n;
int waitfor;
retry:
#ifdef USE_SSL
waitfor = 0;
if (port->ssl_in_use)
{
n = be_tls_read(port, ptr, len, &waitfor);
}
else
#endif
{
n = secure_raw_read(port, ptr, len);
waitfor = WL_SOCKET_READABLE;
}
/* In blocking mode, wait until the socket is ready */
if (n < 0 && !port->noblock && (errno == EWOULDBLOCK || errno == EAGAIN))
{
int w;
Assert(waitfor);
w = WaitLatchOrSocket(MyLatch,
WL_LATCH_SET | WL_POSTMASTER_DEATH | waitfor,
port->sock, 0);
/*
* If the postmaster has died, it's not safe to continue running,
* because it is the postmaster's job to kill us if some other backend
* exists uncleanly. Moreover, we won't run very well in this state;
* helper processes like walwriter and the bgwriter will exit, so
* performance may be poor. Finally, if we don't exit, pg_ctl will
* be unable to restart the postmaster without manual intervention,
* so no new connections can be accepted. Exiting clears the deck
* for a postmaster restart.
*
* (Note that we only make this check when we would otherwise sleep
* on our latch. We might still continue running for a while if the
* postmaster is killed in mid-query, or even through multiple queries
* if we never have to wait for read. We don't want to burn too many
* cycles checking for this very rare condition, and this should cause
* us to exit quickly in most cases.)
*/
if (w & WL_POSTMASTER_DEATH)
ereport(FATAL,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating connection due to unexpected postmaster exit")));
/* Handle interrupt. */
if (w & WL_LATCH_SET)
{
ResetLatch(MyLatch);
ProcessClientReadInterrupt(true);
/*
* We'll retry the read. Most likely it will return immediately
* because there's still no data available, and we'll wait for the
* socket to become ready again.
*/
}
goto retry;
}
/*
* Process interrupts that happened while (or before) receiving. Note that
* we signal that we're not blocking, which will prevent some types of
* interrupts from being processed.
*/
ProcessClientReadInterrupt(false);
return n;
}
ssize_t
secure_raw_read(Port *port, void *ptr, size_t len)
{
ssize_t n;
/*
* Try to read from the socket without blocking. If it succeeds we're
* done, otherwise we'll wait for the socket using the latch mechanism.
*/
#ifdef WIN32
pgwin32_noblock = true;
#endif
n = recv(port->sock, ptr, len, 0);
#ifdef WIN32
pgwin32_noblock = false;
#endif
return n;
}
/*
* Write data to a secure connection.
*/
ssize_t
secure_write(Port *port, void *ptr, size_t len)
{
ssize_t n;
int waitfor;
retry:
waitfor = 0;
#ifdef USE_SSL
if (port->ssl_in_use)
{
n = be_tls_write(port, ptr, len, &waitfor);
}
else
#endif
{
n = secure_raw_write(port, ptr, len);
waitfor = WL_SOCKET_WRITEABLE;
}
if (n < 0 && !port->noblock && (errno == EWOULDBLOCK || errno == EAGAIN))
{
int w;
Assert(waitfor);
w = WaitLatchOrSocket(MyLatch,
WL_LATCH_SET | WL_POSTMASTER_DEATH | waitfor,
port->sock, 0);
/* See comments in secure_read. */
if (w & WL_POSTMASTER_DEATH)
ereport(FATAL,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating connection due to unexpected postmaster exit")));
/* Handle interrupt. */
if (w & WL_LATCH_SET)
{
ResetLatch(MyLatch);
ProcessClientWriteInterrupt(true);
/*
* We'll retry the write. Most likely it will return immediately
* because there's still no data available, and we'll wait for the
* socket to become ready again.
*/
}
goto retry;
}
/*
* Process interrupts that happened while (or before) sending. Note that
* we signal that we're not blocking, which will prevent some types of
* interrupts from being processed.
*/
ProcessClientWriteInterrupt(false);
return n;
}
ssize_t
secure_raw_write(Port *port, const void *ptr, size_t len)
{
ssize_t n;
#ifdef WIN32
pgwin32_noblock = true;
#endif
n = send(port->sock, ptr, len, 0);
#ifdef WIN32
pgwin32_noblock = false;
#endif
return n;
}