pg_upgrade: Check version of target cluster binaries

This expands the binary validation in pg_upgrade with a version
check per binary to ensure that the target cluster installation
only contains binaries from the target version.

In order to reduce duplication, validate_exec is exported from
port.h and the local copy in pg_upgrade is removed.

Author: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://www.postgresql.org/message-id/flat/9328.1552952117@sss.pgh.pa.us

diff --git a/src/bin/pg_upgrade/exec.c b/src/bin/pg_upgrade/exec.c
index 43a4565c2eff0b1e08751b512247161c42f9537f..4d77543d6f4fe5720f876a8f970319378332742a 100644 (file)
--- a/src/bin/pg_upgrade/exec.c
+++ b/src/bin/pg_upgrade/exec.c
@@ -11,12 +11,13 @@
 
 #include <fcntl.h>
 
+#include "common/string.h"
 #include "pg_upgrade.h"
 
 static void check_data_dir(ClusterInfo *cluster);
 static void check_bin_dir(ClusterInfo *cluster);
 static void get_bin_version(ClusterInfo *cluster);
-static void validate_exec(const char *dir, const char *cmdName);
+static void check_exec(const char *dir, const char *program);
 
 #ifdef WIN32
 static int win32_check_directory_write_permissions(void);
@@ -375,9 +376,9 @@ check_bin_dir(ClusterInfo *cluster)
        report_status(PG_FATAL, "\"%s\" is not a directory\n",
                      cluster->bindir);
 
-   validate_exec(cluster->bindir, "postgres");
-   validate_exec(cluster->bindir, "pg_controldata");
-   validate_exec(cluster->bindir, "pg_ctl");
+   check_exec(cluster->bindir, "postgres");
+   check_exec(cluster->bindir, "pg_controldata");
+   check_exec(cluster->bindir, "pg_ctl");
 
    /*
     * Fetch the binary version after checking for the existence of pg_ctl.
@@ -388,9 +389,9 @@ check_bin_dir(ClusterInfo *cluster)
 
    /* pg_resetxlog has been renamed to pg_resetwal in version 10 */
    if (GET_MAJOR_VERSION(cluster->bin_version) <= 906)
-       validate_exec(cluster->bindir, "pg_resetxlog");
+       check_exec(cluster->bindir, "pg_resetxlog");
    else
-       validate_exec(cluster->bindir, "pg_resetwal");
+       check_exec(cluster->bindir, "pg_resetwal");
 
    if (cluster == &new_cluster)
    {
@@ -399,63 +400,46 @@ check_bin_dir(ClusterInfo *cluster)
         * pg_dumpall are used to dump the old cluster, but must be of the
         * target version.
         */
-       validate_exec(cluster->bindir, "initdb");
-       validate_exec(cluster->bindir, "pg_dump");
-       validate_exec(cluster->bindir, "pg_dumpall");
-       validate_exec(cluster->bindir, "pg_restore");
-       validate_exec(cluster->bindir, "psql");
-       validate_exec(cluster->bindir, "vacuumdb");
+       check_exec(cluster->bindir, "initdb");
+       check_exec(cluster->bindir, "pg_dump");
+       check_exec(cluster->bindir, "pg_dumpall");
+       check_exec(cluster->bindir, "pg_restore");
+       check_exec(cluster->bindir, "psql");
+       check_exec(cluster->bindir, "vacuumdb");
    }
 }
 
-
-/*
- * validate_exec()
- *
- * validate "path" as an executable file
- */
 static void
-validate_exec(const char *dir, const char *cmdName)
+check_exec(const char *dir, const char *program)
 {
-   char        path[MAXPGPATH];
-   struct stat buf;
+   char    path[MAXPGPATH];
+   char    line[MAXPGPATH];
+   char    cmd[MAXPGPATH];
+   char    versionstr[128];
+   int     ret;
 
-   snprintf(path, sizeof(path), "%s/%s", dir, cmdName);
+   snprintf(path, sizeof(path), "%s/%s", dir, program);
 
-#ifdef WIN32
-   /* Windows requires a .exe suffix for stat() */
-   if (strlen(path) <= strlen(EXE_EXT) ||
-       pg_strcasecmp(path + strlen(path) - strlen(EXE_EXT), EXE_EXT) != 0)
-       strlcat(path, EXE_EXT, sizeof(path));
-#endif
+   ret = validate_exec(path);
 
-   /*
-    * Ensure that the file exists and is a regular file.
-    */
-   if (stat(path, &buf) < 0)
-       pg_fatal("check for \"%s\" failed: %s\n",
-                path, strerror(errno));
-   else if (!S_ISREG(buf.st_mode))
+   if (ret == -1)
        pg_fatal("check for \"%s\" failed: not a regular file\n",
                 path);
-
-   /*
-    * Ensure that the file is both executable and readable (required for
-    * dynamic loading).
-    */
-#ifndef WIN32
-   if (access(path, R_OK) != 0)
-#else
-   if ((buf.st_mode & S_IRUSR) == 0)
-#endif
-       pg_fatal("check for \"%s\" failed: cannot read file (permission denied)\n",
+   else if (ret == -2)
+       pg_fatal("check for \"%s\" failed: cannot execute (permission denied)\n",
                 path);
 
-#ifndef WIN32
-   if (access(path, X_OK) != 0)
-#else
-   if ((buf.st_mode & S_IXUSR) == 0)
-#endif
-       pg_fatal("check for \"%s\" failed: cannot execute (permission denied)\n",
+   snprintf(cmd, sizeof(cmd), "\"%s\" -V", path);
+
+   if (!pipe_read_line(cmd, line, sizeof(line)))
+       pg_fatal("check for \"%s\" failed: cannot execute\n",
                 path);
+
+   pg_strip_crlf(line);
+
+   snprintf(versionstr, sizeof(versionstr), "%s (PostgreSQL) " PG_VERSION, program);
+
+   if (strcmp(line, versionstr) != 0)
+       pg_fatal("check for \"%s\" failed: incorrect version: found \"%s\", expected \"%s\"\n",
+                path, line, versionstr);
 }

diff --git a/src/common/exec.c b/src/common/exec.c
index 6cbc8200421c8e9525e6b2d4ae5908abc3f68aaa..66c3aa6accfb406320c14ae1869596e71f1e7eae 100644 (file)
--- a/src/common/exec.c
+++ b/src/common/exec.c
@@ -49,7 +49,6 @@
 #define getcwd(cwd,len)  GetCurrentDirectory(len, cwd)
 #endif
 
-static int validate_exec(const char *path);
 static int resolve_symlinks(char *path);
 
 #ifdef WIN32
@@ -63,7 +62,7 @@ static BOOL GetTokenUser(HANDLE hToken, PTOKEN_USER *ppTokenUser);
  *       -1 if the regular file "path" does not exist or cannot be executed.
  *       -2 if the file is otherwise valid but cannot be read.
  */
-static int
+int
 validate_exec(const char *path)
 {
    struct stat buf;

diff --git a/src/include/port.h b/src/include/port.h
index 6486db9fddec02d2bdf32940d06d239909ff9d93..227ef4b148263da1f5aa352ee794e7e64cddf62d 100644 (file)
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -125,6 +125,7 @@ extern void pgfnames_cleanup(char **filenames);
 extern void set_pglocale_pgservice(const char *argv0, const char *app);
 
 /* Portable way to find and execute binaries (in exec.c) */
+extern int validate_exec(const char *path);
 extern int find_my_exec(const char *argv0, char *retpath);
 extern int find_other_exec(const char *argv0, const char *target,
                            const char *versionstr, char *retpath);