Run pg_upgrade and pg_resetxlog with restricted token on Windows

As with initdb these programs need to run with a restricted token, and
if they don't pg_upgrade will fail when run as a user with Adminstrator
privileges.

Backpatch to all live branches. On the development branch the code is
reorganized so that the restricted token code is now in a single
location. On the stable bramches a less invasive change is made by
simply copying the relevant code to pg_upgrade.c and pg_resetxlog.c.

Patches and bug report from Muhammad Asif Naeem, reviewed by Michael
Paquier, slightly edited by me.
This commit is contained in:
Andrew Dunstan 2015-03-30 17:18:10 -04:00
parent 8f3c577212
commit bf22a8e585
2 changed files with 364 additions and 0 deletions

View File

@ -21,7 +21,16 @@ static void copy_clog_xlog_xid(migratorContext *ctx);
static void set_frozenxids(migratorContext *ctx);
static void setup(migratorContext *ctx, char *argv0, bool live_check);
static void cleanup(migratorContext *ctx);
static void get_restricted_token(const char *progname);
#ifdef WIN32
static char * pg_strdupn(const char *str);
static int CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo, const char *progname);
#endif
#ifdef WIN32
static char *restrict_env;
#endif
int
main(int argc, char **argv)
@ -35,6 +44,8 @@ main(int argc, char **argv)
parseCommandLine(&ctx, argc, argv);
get_restricted_token(ctx.progname);
output_check_banner(&ctx, &live_check);
setup(&ctx, argv[0], live_check);
@ -103,6 +114,162 @@ main(int argc, char **argv)
return 0;
}
#ifdef WIN32
typedef BOOL(WINAPI * __CreateRestrictedToken) (HANDLE, DWORD, DWORD, PSID_AND_ATTRIBUTES, DWORD, PLUID_AND_ATTRIBUTES, DWORD, PSID_AND_ATTRIBUTES, PHANDLE);
/* Windows API define missing from some versions of MingW headers */
#ifndef DISABLE_MAX_PRIVILEGE
#define DISABLE_MAX_PRIVILEGE 0x1
#endif
/*
* Create a restricted token and execute the specified process with it.
*
* Returns 0 on failure, non-zero on success, same as CreateProcess().
*
* On NT4, or any other system not containing the required functions, will
* NOT execute anything.
*/
static int
CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo, const char *progname)
{
BOOL b;
STARTUPINFO si;
HANDLE origToken;
HANDLE restrictedToken;
SID_IDENTIFIER_AUTHORITY NtAuthority = { SECURITY_NT_AUTHORITY };
SID_AND_ATTRIBUTES dropSids[2];
__CreateRestrictedToken _CreateRestrictedToken = NULL;
HANDLE Advapi32Handle;
ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);
Advapi32Handle = LoadLibrary("ADVAPI32.DLL");
if (Advapi32Handle != NULL)
{
_CreateRestrictedToken = (__CreateRestrictedToken)GetProcAddress(Advapi32Handle, "CreateRestrictedToken");
}
if (_CreateRestrictedToken == NULL)
{
fprintf(stderr, _("%s: WARNING: cannot create restricted tokens on this platform\n"), progname);
if (Advapi32Handle != NULL)
FreeLibrary(Advapi32Handle);
return 0;
}
/* Open the current token to use as a base for the restricted one */
if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ALL_ACCESS, &origToken))
{
fprintf(stderr, _("%s: could not open process token: error code %lu\n"), progname, GetLastError());
return 0;
}
/* Allocate list of SIDs to remove */
ZeroMemory(&dropSids, sizeof(dropSids));
if (!AllocateAndInitializeSid(&NtAuthority, 2,
SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0, 0, 0,
0, &dropSids[0].Sid) ||
!AllocateAndInitializeSid(&NtAuthority, 2,
SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_POWER_USERS, 0, 0, 0, 0, 0,
0, &dropSids[1].Sid))
{
fprintf(stderr, _("%s: could not to allocate SIDs: error code %lu\n"), progname, GetLastError());
return 0;
}
b = _CreateRestrictedToken(origToken,
DISABLE_MAX_PRIVILEGE,
sizeof(dropSids) / sizeof(dropSids[0]),
dropSids,
0, NULL,
0, NULL,
&restrictedToken);
FreeSid(dropSids[1].Sid);
FreeSid(dropSids[0].Sid);
CloseHandle(origToken);
FreeLibrary(Advapi32Handle);
if (!b)
{
fprintf(stderr, _("%s: could not create restricted token: error code %lu\n"), progname, GetLastError());
return 0;
}
#ifndef __CYGWIN__
AddUserToTokenDacl(restrictedToken);
#endif
if (!CreateProcessAsUser(restrictedToken,
NULL,
cmd,
NULL,
NULL,
TRUE,
CREATE_SUSPENDED,
NULL,
NULL,
&si,
processInfo))
{
fprintf(stderr, _("%s: could not start process for command \"%s\": error code %lu\n"), progname, cmd, GetLastError());
return 0;
}
return ResumeThread(processInfo->hThread);
}
#endif
void
get_restricted_token(const char *progname)
{
#ifdef WIN32
/*
* Before we execute another program, make sure that we are running with a
* restricted token. If not, re-execute ourselves with one.
*/
if ((restrict_env = getenv("PG_RESTRICT_EXEC")) == NULL
|| strcmp(restrict_env, "1") != 0)
{
PROCESS_INFORMATION pi;
char *cmdline;
ZeroMemory(&pi, sizeof(pi));
cmdline = pg_strdupn(GetCommandLine());
putenv("PG_RESTRICT_EXEC=1");
if (!CreateRestrictedProcess(cmdline, &pi, progname))
{
fprintf(stderr, _("%s: could not re-execute with restricted token: error code %lu\n"), progname, GetLastError());
}
else
{
/*
* Successfully re-execed. Now wait for child process to capture
* exitcode.
*/
DWORD x;
CloseHandle(pi.hThread);
WaitForSingleObject(pi.hProcess, INFINITE);
if (!GetExitCodeProcess(pi.hProcess, &x))
{
fprintf(stderr, _("%s: could not get exit code from subprocess: error code %lu\n"), progname, GetLastError());
exit(1);
}
exit(x);
}
}
#endif
}
static void
setup(migratorContext *ctx, char *argv0, bool live_check)
@ -443,3 +610,18 @@ cleanup(migratorContext *ctx)
snprintf(filename, sizeof(filename), "%s/%s", ctx->cwd, DB_DUMP_FILE);
unlink(filename);
}
#ifdef WIN32
static char *
pg_strdupn(const char *str)
{
char *result = strdup(str);
if (!result)
{
fprintf(stderr, _("out of memory\n"));
exit(1);
}
return result;
}
#endif

View File

@ -65,6 +65,11 @@ static uint32 newXlogId,
static bool guessed = false; /* T if we had to guess at any values */
static const char *progname;
#ifdef WIN32
static char *pg_strdup(const char *str);
static char *restrict_env;
#endif
static bool ReadControlFile(void);
static void GuessControlValues(void);
static void PrintControlValues(bool guessed);
@ -74,7 +79,11 @@ static void KillExistingXLOG(void);
static void KillExistingArchiveStatus(void);
static void WriteEmptyXLOG(void);
static void usage(void);
static void get_restricted_token(const char *progname);
#ifdef WIN32
static int CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo, const char *progname);
#endif
int
main(int argc, char *argv[])
@ -256,6 +265,7 @@ main(int argc, char *argv[])
}
#endif
get_restricted_token(progname);
DataDir = argv[optind];
if (chdir(DataDir) < 0)
@ -380,6 +390,22 @@ main(int argc, char *argv[])
return 0;
}
#ifdef WIN32
static char *
pg_strdup(const char *str)
{
char *result = strdup(str);
if (!result)
{
fprintf(stderr, _("out of memory\n"));
exit(1);
}
return result;
}
#endif
/*
* Try to read the existing pg_control file.
@ -1016,6 +1042,162 @@ WriteEmptyXLOG(void)
close(fd);
}
#ifdef WIN32
typedef BOOL(WINAPI * __CreateRestrictedToken) (HANDLE, DWORD, DWORD, PSID_AND_ATTRIBUTES, DWORD, PLUID_AND_ATTRIBUTES, DWORD, PSID_AND_ATTRIBUTES, PHANDLE);
/* Windows API define missing from some versions of MingW headers */
#ifndef DISABLE_MAX_PRIVILEGE
#define DISABLE_MAX_PRIVILEGE 0x1
#endif
/*
* Create a restricted token and execute the specified process with it.
*
* Returns 0 on failure, non-zero on success, same as CreateProcess().
*
* On NT4, or any other system not containing the required functions, will
* NOT execute anything.
*/
static int
CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo, const char *progname)
{
BOOL b;
STARTUPINFO si;
HANDLE origToken;
HANDLE restrictedToken;
SID_IDENTIFIER_AUTHORITY NtAuthority = { SECURITY_NT_AUTHORITY };
SID_AND_ATTRIBUTES dropSids[2];
__CreateRestrictedToken _CreateRestrictedToken = NULL;
HANDLE Advapi32Handle;
ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);
Advapi32Handle = LoadLibrary("ADVAPI32.DLL");
if (Advapi32Handle != NULL)
{
_CreateRestrictedToken = (__CreateRestrictedToken)GetProcAddress(Advapi32Handle, "CreateRestrictedToken");
}
if (_CreateRestrictedToken == NULL)
{
fprintf(stderr, _("%s: WARNING: cannot create restricted tokens on this platform\n"), progname);
if (Advapi32Handle != NULL)
FreeLibrary(Advapi32Handle);
return 0;
}
/* Open the current token to use as a base for the restricted one */
if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ALL_ACCESS, &origToken))
{
fprintf(stderr, _("%s: could not open process token: error code %lu\n"), progname, GetLastError());
return 0;
}
/* Allocate list of SIDs to remove */
ZeroMemory(&dropSids, sizeof(dropSids));
if (!AllocateAndInitializeSid(&NtAuthority, 2,
SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0, 0, 0,
0, &dropSids[0].Sid) ||
!AllocateAndInitializeSid(&NtAuthority, 2,
SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_POWER_USERS, 0, 0, 0, 0, 0,
0, &dropSids[1].Sid))
{
fprintf(stderr, _("%s: could not to allocate SIDs: error code %lu\n"), progname, GetLastError());
return 0;
}
b = _CreateRestrictedToken(origToken,
DISABLE_MAX_PRIVILEGE,
sizeof(dropSids) / sizeof(dropSids[0]),
dropSids,
0, NULL,
0, NULL,
&restrictedToken);
FreeSid(dropSids[1].Sid);
FreeSid(dropSids[0].Sid);
CloseHandle(origToken);
FreeLibrary(Advapi32Handle);
if (!b)
{
fprintf(stderr, _("%s: could not create restricted token: error code %lu\n"), progname, GetLastError());
return 0;
}
#ifndef __CYGWIN__
AddUserToTokenDacl(restrictedToken);
#endif
if (!CreateProcessAsUser(restrictedToken,
NULL,
cmd,
NULL,
NULL,
TRUE,
CREATE_SUSPENDED,
NULL,
NULL,
&si,
processInfo))
{
fprintf(stderr, _("%s: could not start process for command \"%s\": error code %lu\n"), progname, cmd, GetLastError());
return 0;
}
return ResumeThread(processInfo->hThread);
}
#endif
void
get_restricted_token(const char *progname)
{
#ifdef WIN32
/*
* Before we execute another program, make sure that we are running with a
* restricted token. If not, re-execute ourselves with one.
*/
if ((restrict_env = getenv("PG_RESTRICT_EXEC")) == NULL
|| strcmp(restrict_env, "1") != 0)
{
PROCESS_INFORMATION pi;
char *cmdline;
ZeroMemory(&pi, sizeof(pi));
cmdline = pg_strdup(GetCommandLine());
putenv("PG_RESTRICT_EXEC=1");
if (!CreateRestrictedProcess(cmdline, &pi, progname))
{
fprintf(stderr, _("%s: could not re-execute with restricted token: error code %lu\n"), progname, GetLastError());
}
else
{
/*
* Successfully re-execed. Now wait for child process to capture
* exitcode.
*/
DWORD x;
CloseHandle(pi.hThread);
WaitForSingleObject(pi.hProcess, INFINITE);
if (!GetExitCodeProcess(pi.hProcess, &x))
{
fprintf(stderr, _("%s: could not get exit code from subprocess: error code %lu\n"), progname, GetLastError());
exit(1);
}
exit(x);
}
}
#endif
}
static void
usage(void)