src/interfaces/libpq-oauth/oauth-utils.c - master - githubmirror/postgres

src/interfaces/libpq-oauth/oauth-utils.c
155 строк4 KB
Jacob Champion
libpq: Split PGOAUTHDEBUG=UNSAFE into multiple options
07 апр 2026, 18:15
07 апр 2026, 18:156d00fb9
/*-------------------------------------------------------------------------
 *
 * oauth-utils.c
 *
 *	  "Glue" helpers providing a copy of some internal APIs from libpq. At
 *	  some point in the future, we might be able to deduplicate.
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *	  src/interfaces/libpq-oauth/oauth-utils.c
 *
 *-------------------------------------------------------------------------
 */

#include "postgres_fe.h"

#include <signal.h>

#include "oauth-utils.h"

#ifndef USE_DYNAMIC_OAUTH
#error oauth-utils.c is not supported in static builds
#endif

#ifdef LIBPQ_INT_H
#error do not rely on libpq-int.h in dynamic builds of libpq-oauth
#endif

/*
 * Function pointers set by libpq_oauth_init().
 */

pgthreadlock_t pg_g_threadlock;
static libpq_gettext_func libpq_gettext_impl;

/*-
 * Initializes libpq-oauth by setting necessary callbacks.
 *
 * The current implementation relies on libpq_gettext to translate error
 * messages using libpq's message domain, so libpq injects it here. We also use
 * this chance to initialize our threadlock.
 */
void
libpq_oauth_init(libpq_gettext_func gettext_impl)
{
	pg_g_threadlock = PQgetThreadLock();
	libpq_gettext_impl = gettext_impl;
}

#ifdef ENABLE_NLS

/*
 * A shim that defers to the actual libpq_gettext().
 */
char *
libpq_gettext(const char *msgid)
{
	if (!libpq_gettext_impl)
	{
		/*
		 * Possible if the libpq build didn't enable NLS but the libpq-oauth
		 * build did. That's an odd mismatch, but we can handle it.
		 *
		 * Note that callers of libpq_gettext() have to treat the return value
		 * as if it were const, because builds without NLS simply pass through
		 * their argument.
		 */
		return unconstify(char *, msgid);
	}

	return libpq_gettext_impl(msgid);
}

#endif							/* ENABLE_NLS */

/*
 * Duplicate SOCK_ERRNO* definitions from libpq-int.h, for use by
 * pq_block/reset_sigpipe().
 */
#ifdef WIN32
#define SOCK_ERRNO (WSAGetLastError())
#define SOCK_ERRNO_SET(e) WSASetLastError(e)
#else
#define SOCK_ERRNO errno
#define SOCK_ERRNO_SET(e) (errno = (e))
#endif

/*
 *	Block SIGPIPE for this thread. This is a copy of libpq's internal API.
 */
int
pq_block_sigpipe(sigset_t *osigset, bool *sigpipe_pending)
{
	sigset_t	sigpipe_sigset;
	sigset_t	sigset;

	sigemptyset(&sigpipe_sigset);
	sigaddset(&sigpipe_sigset, SIGPIPE);

	/* Block SIGPIPE and save previous mask for later reset */
	SOCK_ERRNO_SET(pthread_sigmask(SIG_BLOCK, &sigpipe_sigset, osigset));
	if (SOCK_ERRNO)
		return -1;

	/* We can have a pending SIGPIPE only if it was blocked before */
	if (sigismember(osigset, SIGPIPE))
	{
		/* Is there a pending SIGPIPE? */
		if (sigpending(&sigset) != 0)
			return -1;

		if (sigismember(&sigset, SIGPIPE))
			*sigpipe_pending = true;
		else
			*sigpipe_pending = false;
	}
	else
		*sigpipe_pending = false;

	return 0;
}

/*
 *	Discard any pending SIGPIPE and reset the signal mask. This is a copy of
 *	libpq's internal API.
 */
void
pq_reset_sigpipe(sigset_t *osigset, bool sigpipe_pending, bool got_epipe)
{
	int			save_errno = SOCK_ERRNO;
	int			signo;
	sigset_t	sigset;

	/* Clear SIGPIPE only if none was pending */
	if (got_epipe && !sigpipe_pending)
	{
		if (sigpending(&sigset) == 0 &&
			sigismember(&sigset, SIGPIPE))
		{
			sigset_t	sigpipe_sigset;

			sigemptyset(&sigpipe_sigset);
			sigaddset(&sigpipe_sigset, SIGPIPE);

			sigwait(&sigpipe_sigset, &signo);
		}
	}

	/* Restore saved block mask */
	pthread_sigmask(SIG_SETMASK, osigset, NULL);

	SOCK_ERRNO_SET(save_errno);
}