LCOV - code coverage report
Current view: top level - src/bin/pg_basebackup - pg_receivewal.c (source / functions) Coverage Total Hit
Test: PostgreSQL 19devel Lines: 78.0 % 372 290
Test Date: 2026-03-03 18:14:56 Functions: 90.0 % 10 9
Legend: Lines:     hit not hit

            Line data    Source code
       1              : /*-------------------------------------------------------------------------
       2              :  *
       3              :  * pg_receivewal.c - receive streaming WAL data and write it
       4              :  *                    to a local file.
       5              :  *
       6              :  * Author: Magnus Hagander <magnus@hagander.net>
       7              :  *
       8              :  * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
       9              :  *
      10              :  * IDENTIFICATION
      11              :  *        src/bin/pg_basebackup/pg_receivewal.c
      12              :  *-------------------------------------------------------------------------
      13              :  */
      14              : 
      15              : #include "postgres_fe.h"
      16              : 
      17              : #include <dirent.h>
      18              : #include <limits.h>
      19              : #include <signal.h>
      20              : #include <sys/stat.h>
      21              : #include <unistd.h>
      22              : 
      23              : #ifdef USE_LZ4
      24              : #include <lz4frame.h>
      25              : #endif
      26              : #ifdef HAVE_LIBZ
      27              : #include <zlib.h>
      28              : #endif
      29              : 
      30              : #include "access/xlog_internal.h"
      31              : #include "common/file_perm.h"
      32              : #include "common/logging.h"
      33              : #include "fe_utils/option_utils.h"
      34              : #include "getopt_long.h"
      35              : #include "libpq-fe.h"
      36              : #include "receivelog.h"
      37              : #include "streamutil.h"
      38              : 
      39              : /* Time to sleep between reconnection attempts */
      40              : #define RECONNECT_SLEEP_TIME 5
      41              : 
      42              : /* Global options */
      43              : static char *basedir = NULL;
      44              : static int  verbose = 0;
      45              : static int  compresslevel = 0;
      46              : static bool noloop = false;
      47              : static int  standby_message_timeout = 10 * 1000;    /* 10 sec = default */
      48              : static volatile sig_atomic_t time_to_stop = false;
      49              : static bool do_create_slot = false;
      50              : static bool slot_exists_ok = false;
      51              : static bool do_drop_slot = false;
      52              : static bool do_sync = true;
      53              : static bool synchronous = false;
      54              : static char *replication_slot = NULL;
      55              : static pg_compress_algorithm compression_algorithm = PG_COMPRESSION_NONE;
      56              : static XLogRecPtr endpos = InvalidXLogRecPtr;
      57              : 
      58              : 
      59              : static void usage(void);
      60              : static DIR *get_destination_dir(char *dest_folder);
      61              : static void close_destination_dir(DIR *dest_dir, char *dest_folder);
      62              : static XLogRecPtr FindStreamingStart(uint32 *tli);
      63              : static void StreamLog(void);
      64              : static bool stop_streaming(XLogRecPtr xlogpos, uint32 timeline,
      65              :                            bool segment_finished);
      66              : 
      67              : static void
      68            9 : disconnect_atexit(void)
      69              : {
      70            9 :     if (conn != NULL)
      71            3 :         PQfinish(conn);
      72            9 : }
      73              : 
      74              : static void
      75            1 : usage(void)
      76              : {
      77            1 :     printf(_("%s receives PostgreSQL streaming write-ahead logs.\n\n"),
      78              :            progname);
      79            1 :     printf(_("Usage:\n"));
      80            1 :     printf(_("  %s [OPTION]...\n"), progname);
      81            1 :     printf(_("\nOptions:\n"));
      82            1 :     printf(_("  -D, --directory=DIR    receive write-ahead log files into this directory\n"));
      83            1 :     printf(_("  -E, --endpos=LSN       exit after receiving the specified LSN\n"));
      84            1 :     printf(_("      --if-not-exists    do not error if slot already exists when creating a slot\n"));
      85            1 :     printf(_("  -n, --no-loop          do not loop on connection lost\n"));
      86            1 :     printf(_("      --no-sync          do not wait for changes to be written safely to disk\n"));
      87            1 :     printf(_("  -s, --status-interval=SECS\n"
      88              :              "                         time between status packets sent to server (default: %d)\n"), (standby_message_timeout / 1000));
      89            1 :     printf(_("  -S, --slot=SLOTNAME    replication slot to use\n"));
      90            1 :     printf(_("      --synchronous      flush write-ahead log immediately after writing\n"));
      91            1 :     printf(_("  -v, --verbose          output verbose messages\n"));
      92            1 :     printf(_("  -V, --version          output version information, then exit\n"));
      93            1 :     printf(_("  -Z, --compress=METHOD[:DETAIL]\n"
      94              :              "                         compress as specified\n"));
      95            1 :     printf(_("  -?, --help             show this help, then exit\n"));
      96            1 :     printf(_("\nConnection options:\n"));
      97            1 :     printf(_("  -d, --dbname=CONNSTR   connection string\n"));
      98            1 :     printf(_("  -h, --host=HOSTNAME    database server host or socket directory\n"));
      99            1 :     printf(_("  -p, --port=PORT        database server port number\n"));
     100            1 :     printf(_("  -U, --username=NAME    connect as specified database user\n"));
     101            1 :     printf(_("  -w, --no-password      never prompt for password\n"));
     102            1 :     printf(_("  -W, --password         force password prompt (should happen automatically)\n"));
     103            1 :     printf(_("\nOptional actions:\n"));
     104            1 :     printf(_("      --create-slot      create a new replication slot (for the slot's name see --slot)\n"));
     105            1 :     printf(_("      --drop-slot        drop the replication slot (for the slot's name see --slot)\n"));
     106            1 :     printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
     107            1 :     printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
     108            1 : }
     109              : 
     110              : 
     111              : /*
     112              :  * Check if the filename looks like a WAL file, letting caller know if this
     113              :  * WAL segment is partial and/or compressed.
     114              :  */
     115              : static bool
     116           23 : is_xlogfilename(const char *filename, bool *ispartial,
     117              :                 pg_compress_algorithm *wal_compression_algorithm)
     118              : {
     119           23 :     size_t      fname_len = strlen(filename);
     120           23 :     size_t      xlog_pattern_len = strspn(filename, "0123456789ABCDEF");
     121              : 
     122              :     /* File does not look like a WAL file */
     123           23 :     if (xlog_pattern_len != XLOG_FNAME_LEN)
     124           14 :         return false;
     125              : 
     126              :     /* File looks like a completed uncompressed WAL file */
     127            9 :     if (fname_len == XLOG_FNAME_LEN)
     128              :     {
     129            0 :         *ispartial = false;
     130            0 :         *wal_compression_algorithm = PG_COMPRESSION_NONE;
     131            0 :         return true;
     132              :     }
     133              : 
     134              :     /* File looks like a completed gzip-compressed WAL file */
     135            9 :     if (fname_len == XLOG_FNAME_LEN + strlen(".gz") &&
     136            2 :         strcmp(filename + XLOG_FNAME_LEN, ".gz") == 0)
     137              :     {
     138            2 :         *ispartial = false;
     139            2 :         *wal_compression_algorithm = PG_COMPRESSION_GZIP;
     140            2 :         return true;
     141              :     }
     142              : 
     143              :     /* File looks like a completed LZ4-compressed WAL file */
     144            7 :     if (fname_len == XLOG_FNAME_LEN + strlen(".lz4") &&
     145            1 :         strcmp(filename + XLOG_FNAME_LEN, ".lz4") == 0)
     146              :     {
     147            1 :         *ispartial = false;
     148            1 :         *wal_compression_algorithm = PG_COMPRESSION_LZ4;
     149            1 :         return true;
     150              :     }
     151              : 
     152              :     /* File looks like a partial uncompressed WAL file */
     153            6 :     if (fname_len == XLOG_FNAME_LEN + strlen(".partial") &&
     154            3 :         strcmp(filename + XLOG_FNAME_LEN, ".partial") == 0)
     155              :     {
     156            3 :         *ispartial = true;
     157            3 :         *wal_compression_algorithm = PG_COMPRESSION_NONE;
     158            3 :         return true;
     159              :     }
     160              : 
     161              :     /* File looks like a partial gzip-compressed WAL file */
     162            3 :     if (fname_len == XLOG_FNAME_LEN + strlen(".gz.partial") &&
     163            2 :         strcmp(filename + XLOG_FNAME_LEN, ".gz.partial") == 0)
     164              :     {
     165            2 :         *ispartial = true;
     166            2 :         *wal_compression_algorithm = PG_COMPRESSION_GZIP;
     167            2 :         return true;
     168              :     }
     169              : 
     170              :     /* File looks like a partial LZ4-compressed WAL file */
     171            1 :     if (fname_len == XLOG_FNAME_LEN + strlen(".lz4.partial") &&
     172            1 :         strcmp(filename + XLOG_FNAME_LEN, ".lz4.partial") == 0)
     173              :     {
     174            1 :         *ispartial = true;
     175            1 :         *wal_compression_algorithm = PG_COMPRESSION_LZ4;
     176            1 :         return true;
     177              :     }
     178              : 
     179              :     /* File does not look like something we know */
     180            0 :     return false;
     181              : }
     182              : 
     183              : static bool
     184           86 : stop_streaming(XLogRecPtr xlogpos, uint32 timeline, bool segment_finished)
     185              : {
     186              :     static uint32 prevtimeline = 0;
     187              :     static XLogRecPtr prevpos = InvalidXLogRecPtr;
     188              : 
     189              :     /* we assume that we get called once at the end of each segment */
     190           86 :     if (verbose && segment_finished)
     191            6 :         pg_log_info("finished segment at %X/%08X (timeline %u)",
     192              :                     LSN_FORMAT_ARGS(xlogpos),
     193              :                     timeline);
     194              : 
     195           86 :     if (XLogRecPtrIsValid(endpos) && endpos < xlogpos)
     196              :     {
     197           12 :         if (verbose)
     198           12 :             pg_log_info("stopped log streaming at %X/%08X (timeline %u)",
     199              :                         LSN_FORMAT_ARGS(xlogpos),
     200              :                         timeline);
     201           12 :         time_to_stop = true;
     202           12 :         return true;
     203              :     }
     204              : 
     205              :     /*
     206              :      * Note that we report the previous, not current, position here. After a
     207              :      * timeline switch, xlogpos points to the beginning of the segment because
     208              :      * that's where we always begin streaming. Reporting the end of previous
     209              :      * timeline isn't totally accurate, because the next timeline can begin
     210              :      * slightly before the end of the WAL that we received on the previous
     211              :      * timeline, but it's close enough for reporting purposes.
     212              :      */
     213           74 :     if (verbose && prevtimeline != 0 && prevtimeline != timeline)
     214            1 :         pg_log_info("switched to timeline %u at %X/%08X",
     215              :                     timeline,
     216              :                     LSN_FORMAT_ARGS(prevpos));
     217              : 
     218           74 :     prevtimeline = timeline;
     219           74 :     prevpos = xlogpos;
     220              : 
     221           74 :     if (time_to_stop)
     222              :     {
     223            0 :         if (verbose)
     224            0 :             pg_log_info("received interrupt signal, exiting");
     225            0 :         return true;
     226              :     }
     227           74 :     return false;
     228              : }
     229              : 
     230              : 
     231              : /*
     232              :  * Get destination directory.
     233              :  */
     234              : static DIR *
     235           14 : get_destination_dir(char *dest_folder)
     236              : {
     237              :     DIR        *dir;
     238              : 
     239              :     Assert(dest_folder != NULL);
     240           14 :     dir = opendir(dest_folder);
     241           14 :     if (dir == NULL)
     242            0 :         pg_fatal("could not open directory \"%s\": %m", dest_folder);
     243              : 
     244           14 :     return dir;
     245              : }
     246              : 
     247              : 
     248              : /*
     249              :  * Close existing directory.
     250              :  */
     251              : static void
     252           14 : close_destination_dir(DIR *dest_dir, char *dest_folder)
     253              : {
     254              :     Assert(dest_dir != NULL && dest_folder != NULL);
     255           14 :     if (closedir(dest_dir))
     256            0 :         pg_fatal("could not close directory \"%s\": %m", dest_folder);
     257           14 : }
     258              : 
     259              : 
     260              : /*
     261              :  * Determine starting location for streaming, based on any existing xlog
     262              :  * segments in the directory. We start at the end of the last one that is
     263              :  * complete (size matches wal segment size), on the timeline with highest ID.
     264              :  *
     265              :  * If there are no WAL files in the directory, returns InvalidXLogRecPtr.
     266              :  */
     267              : static XLogRecPtr
     268            7 : FindStreamingStart(uint32 *tli)
     269              : {
     270              :     DIR        *dir;
     271              :     struct dirent *dirent;
     272            7 :     XLogSegNo   high_segno = 0;
     273            7 :     uint32      high_tli = 0;
     274            7 :     bool        high_ispartial = false;
     275              : 
     276            7 :     dir = get_destination_dir(basedir);
     277              : 
     278           30 :     while (errno = 0, (dirent = readdir(dir)) != NULL)
     279              :     {
     280              :         uint32      tli;
     281              :         XLogSegNo   segno;
     282              :         pg_compress_algorithm wal_compression_algorithm;
     283              :         bool        ispartial;
     284              : 
     285           23 :         if (!is_xlogfilename(dirent->d_name,
     286              :                              &ispartial, &wal_compression_algorithm))
     287           14 :             continue;
     288              : 
     289              :         /*
     290              :          * Looks like an xlog file. Parse its position.
     291              :          */
     292            9 :         XLogFromFileName(dirent->d_name, &tli, &segno, WalSegSz);
     293              : 
     294              :         /*
     295              :          * Check that the segment has the right size, if it's supposed to be
     296              :          * completed.  For non-compressed segments just check the on-disk size
     297              :          * and see if it matches a completed segment.  For gzip-compressed
     298              :          * segments, look at the last 4 bytes of the compressed file, which is
     299              :          * where the uncompressed size is located for files with a size lower
     300              :          * than 4GB, and then compare it to the size of a completed segment.
     301              :          * The 4 last bytes correspond to the ISIZE member according to
     302              :          * http://www.zlib.org/rfc-gzip.html.
     303              :          *
     304              :          * For LZ4-compressed segments, uncompress the file in a throw-away
     305              :          * buffer keeping track of the uncompressed size, then compare it to
     306              :          * the size of a completed segment.  Per its protocol, LZ4 does not
     307              :          * store the uncompressed size of an object by default.  contentSize
     308              :          * is one possible way to do that, but we need to rely on a method
     309              :          * where WAL segments could have been compressed by a different source
     310              :          * than pg_receivewal, like an archive_command with lz4.
     311              :          */
     312            9 :         if (!ispartial && wal_compression_algorithm == PG_COMPRESSION_NONE)
     313            0 :         {
     314              :             struct stat statbuf;
     315              :             char        fullpath[MAXPGPATH * 2];
     316              : 
     317            0 :             snprintf(fullpath, sizeof(fullpath), "%s/%s", basedir, dirent->d_name);
     318            0 :             if (stat(fullpath, &statbuf) != 0)
     319            0 :                 pg_fatal("could not stat file \"%s\": %m", fullpath);
     320              : 
     321            0 :             if (statbuf.st_size != WalSegSz)
     322              :             {
     323            0 :                 pg_log_warning("segment file \"%s\" has incorrect size %lld, skipping",
     324              :                                dirent->d_name, (long long int) statbuf.st_size);
     325            0 :                 continue;
     326              :             }
     327              :         }
     328            9 :         else if (!ispartial && wal_compression_algorithm == PG_COMPRESSION_GZIP)
     329            2 :         {
     330              :             int         fd;
     331              :             char        buf[4];
     332              :             int         bytes_out;
     333              :             char        fullpath[MAXPGPATH * 2];
     334              :             int         r;
     335              : 
     336            2 :             snprintf(fullpath, sizeof(fullpath), "%s/%s", basedir, dirent->d_name);
     337              : 
     338            2 :             fd = open(fullpath, O_RDONLY | PG_BINARY, 0);
     339            2 :             if (fd < 0)
     340            0 :                 pg_fatal("could not open compressed file \"%s\": %m",
     341              :                          fullpath);
     342            2 :             if (lseek(fd, (off_t) (-4), SEEK_END) < 0)
     343            0 :                 pg_fatal("could not seek in compressed file \"%s\": %m",
     344              :                          fullpath);
     345            2 :             r = read(fd, buf, sizeof(buf));
     346            2 :             if (r != sizeof(buf))
     347              :             {
     348            0 :                 if (r < 0)
     349            0 :                     pg_fatal("could not read compressed file \"%s\": %m",
     350              :                              fullpath);
     351              :                 else
     352            0 :                     pg_fatal("could not read compressed file \"%s\": read %d of %zu",
     353              :                              fullpath, r, sizeof(buf));
     354              :             }
     355              : 
     356            2 :             close(fd);
     357            2 :             bytes_out = (buf[3] << 24) | (buf[2] << 16) |
     358            2 :                 (buf[1] << 8) | buf[0];
     359              : 
     360            2 :             if (bytes_out != WalSegSz)
     361              :             {
     362            0 :                 pg_log_warning("compressed segment file \"%s\" has incorrect uncompressed size %d, skipping",
     363              :                                dirent->d_name, bytes_out);
     364            0 :                 continue;
     365              :             }
     366              :         }
     367            7 :         else if (!ispartial && wal_compression_algorithm == PG_COMPRESSION_LZ4)
     368              :         {
     369              : #ifdef USE_LZ4
     370              : #define LZ4_CHUNK_SZ    64 * 1024   /* 64kB as maximum chunk size read */
     371              :             int         fd;
     372              :             ssize_t     r;
     373            1 :             size_t      uncompressed_size = 0;
     374              :             char        fullpath[MAXPGPATH * 2];
     375              :             char       *outbuf;
     376              :             char       *readbuf;
     377            1 :             LZ4F_decompressionContext_t ctx = NULL;
     378              :             LZ4F_decompressOptions_t dec_opt;
     379              :             LZ4F_errorCode_t status;
     380              : 
     381            1 :             memset(&dec_opt, 0, sizeof(dec_opt));
     382            1 :             snprintf(fullpath, sizeof(fullpath), "%s/%s", basedir, dirent->d_name);
     383              : 
     384            1 :             fd = open(fullpath, O_RDONLY | PG_BINARY, 0);
     385            1 :             if (fd < 0)
     386            0 :                 pg_fatal("could not open file \"%s\": %m", fullpath);
     387              : 
     388            1 :             status = LZ4F_createDecompressionContext(&ctx, LZ4F_VERSION);
     389            1 :             if (LZ4F_isError(status))
     390            0 :                 pg_fatal("could not create LZ4 decompression context: %s",
     391              :                          LZ4F_getErrorName(status));
     392              : 
     393            1 :             outbuf = pg_malloc0(LZ4_CHUNK_SZ);
     394            1 :             readbuf = pg_malloc0(LZ4_CHUNK_SZ);
     395              :             do
     396              :             {
     397              :                 char       *readp;
     398              :                 char       *readend;
     399              : 
     400            2 :                 r = read(fd, readbuf, LZ4_CHUNK_SZ);
     401            2 :                 if (r < 0)
     402            0 :                     pg_fatal("could not read file \"%s\": %m", fullpath);
     403              : 
     404              :                 /* Done reading the file */
     405            2 :                 if (r == 0)
     406            1 :                     break;
     407              : 
     408              :                 /* Process one chunk */
     409            1 :                 readp = readbuf;
     410            1 :                 readend = readbuf + r;
     411           17 :                 while (readp < readend)
     412              :                 {
     413           16 :                     size_t      out_size = LZ4_CHUNK_SZ;
     414           16 :                     size_t      read_size = readend - readp;
     415              : 
     416           16 :                     memset(outbuf, 0, LZ4_CHUNK_SZ);
     417           16 :                     status = LZ4F_decompress(ctx, outbuf, &out_size,
     418              :                                              readp, &read_size, &dec_opt);
     419           16 :                     if (LZ4F_isError(status))
     420            0 :                         pg_fatal("could not decompress file \"%s\": %s",
     421              :                                  fullpath,
     422              :                                  LZ4F_getErrorName(status));
     423              : 
     424           16 :                     readp += read_size;
     425           16 :                     uncompressed_size += out_size;
     426              :                 }
     427              : 
     428              :                 /*
     429              :                  * No need to continue reading the file when the
     430              :                  * uncompressed_size exceeds WalSegSz, even if there are still
     431              :                  * data left to read. However, if uncompressed_size is equal
     432              :                  * to WalSegSz, it should verify that there is no more data to
     433              :                  * read.
     434              :                  */
     435            1 :             } while (uncompressed_size <= WalSegSz && r > 0);
     436              : 
     437            1 :             close(fd);
     438            1 :             pg_free(outbuf);
     439            1 :             pg_free(readbuf);
     440              : 
     441            1 :             status = LZ4F_freeDecompressionContext(ctx);
     442            1 :             if (LZ4F_isError(status))
     443            0 :                 pg_fatal("could not free LZ4 decompression context: %s",
     444              :                          LZ4F_getErrorName(status));
     445              : 
     446            1 :             if (uncompressed_size != WalSegSz)
     447              :             {
     448            0 :                 pg_log_warning("compressed segment file \"%s\" has incorrect uncompressed size %zu, skipping",
     449              :                                dirent->d_name, uncompressed_size);
     450            0 :                 continue;
     451              :             }
     452              : #else
     453              :             pg_log_error("cannot check file \"%s\": compression with %s not supported by this build",
     454              :                          dirent->d_name, "LZ4");
     455              :             exit(1);
     456              : #endif
     457              :         }
     458              : 
     459              :         /* Looks like a valid segment. Remember that we saw it. */
     460            9 :         if ((segno > high_segno) ||
     461            4 :             (segno == high_segno && tli > high_tli) ||
     462            4 :             (segno == high_segno && tli == high_tli && high_ispartial && !ispartial))
     463              :         {
     464            5 :             high_segno = segno;
     465            5 :             high_tli = tli;
     466            5 :             high_ispartial = ispartial;
     467              :         }
     468              :     }
     469              : 
     470            7 :     if (errno)
     471            0 :         pg_fatal("could not read directory \"%s\": %m", basedir);
     472              : 
     473            7 :     close_destination_dir(dir, basedir);
     474              : 
     475            7 :     if (high_segno > 0)
     476              :     {
     477              :         XLogRecPtr  high_ptr;
     478              : 
     479              :         /*
     480              :          * Move the starting pointer to the start of the next segment, if the
     481              :          * highest one we saw was completed. Otherwise start streaming from
     482              :          * the beginning of the .partial segment.
     483              :          */
     484            3 :         if (!high_ispartial)
     485            0 :             high_segno++;
     486              : 
     487            3 :         XLogSegNoOffsetToRecPtr(high_segno, 0, WalSegSz, high_ptr);
     488              : 
     489            3 :         *tli = high_tli;
     490            3 :         return high_ptr;
     491              :     }
     492              :     else
     493            4 :         return InvalidXLogRecPtr;
     494              : }
     495              : 
     496              : /*
     497              :  * Start the log streaming
     498              :  */
     499              : static void
     500            7 : StreamLog(void)
     501              : {
     502              :     XLogRecPtr  serverpos;
     503              :     TimeLineID  servertli;
     504            7 :     StreamCtl   stream = {0};
     505              :     char       *sysidentifier;
     506              : 
     507              :     /*
     508              :      * Connect in replication mode to the server
     509              :      */
     510            7 :     if (conn == NULL)
     511            0 :         conn = GetConnection();
     512            7 :     if (!conn)
     513              :         /* Error message already written in GetConnection() */
     514            1 :         return;
     515              : 
     516            7 :     if (!CheckServerVersionForStreaming(conn))
     517              :     {
     518              :         /*
     519              :          * Error message already written in CheckServerVersionForStreaming().
     520              :          * There's no hope of recovering from a version mismatch, so don't
     521              :          * retry.
     522              :          */
     523            0 :         exit(1);
     524              :     }
     525              : 
     526              :     /*
     527              :      * Identify server, obtaining start LSN position and current timeline ID
     528              :      * at the same time, necessary if not valid data can be found in the
     529              :      * existing output directory.
     530              :      */
     531            7 :     if (!RunIdentifySystem(conn, &sysidentifier, &servertli, &serverpos, NULL))
     532            0 :         exit(1);
     533              : 
     534              :     /*
     535              :      * Figure out where to start streaming.  First scan the local directory.
     536              :      */
     537            7 :     stream.startpos = FindStreamingStart(&stream.timeline);
     538            7 :     if (!XLogRecPtrIsValid(stream.startpos))
     539              :     {
     540              :         /*
     541              :          * Try to get the starting point from the slot if any.  This is
     542              :          * supported in PostgreSQL 15 and newer.
     543              :          */
     544            7 :         if (replication_slot != NULL &&
     545            3 :             PQserverVersion(conn) >= 150000)
     546              :         {
     547            3 :             if (!GetSlotInformation(conn, replication_slot, &stream.startpos,
     548              :                                     &stream.timeline))
     549              :             {
     550              :                 /* Error is logged by GetSlotInformation() */
     551            1 :                 return;
     552              :             }
     553              :         }
     554              : 
     555              :         /*
     556              :          * If it the starting point is still not known, use the current WAL
     557              :          * flush value as last resort.
     558              :          */
     559            3 :         if (!XLogRecPtrIsValid(stream.startpos))
     560              :         {
     561            1 :             stream.startpos = serverpos;
     562            1 :             stream.timeline = servertli;
     563              :         }
     564              :     }
     565              : 
     566              :     Assert(XLogRecPtrIsValid(stream.startpos) &&
     567              :            stream.timeline != 0);
     568              : 
     569              :     /*
     570              :      * Always start streaming at the beginning of a segment
     571              :      */
     572            6 :     stream.startpos -= XLogSegmentOffset(stream.startpos, WalSegSz);
     573              : 
     574              :     /*
     575              :      * Start the replication
     576              :      */
     577            6 :     if (verbose)
     578            6 :         pg_log_info("starting log streaming at %X/%08X (timeline %u)",
     579              :                     LSN_FORMAT_ARGS(stream.startpos),
     580              :                     stream.timeline);
     581              : 
     582            6 :     stream.stream_stop = stop_streaming;
     583            6 :     stream.stop_socket = PGINVALID_SOCKET;
     584            6 :     stream.standby_message_timeout = standby_message_timeout;
     585            6 :     stream.synchronous = synchronous;
     586            6 :     stream.do_sync = do_sync;
     587            6 :     stream.mark_done = false;
     588           12 :     stream.walmethod = CreateWalDirectoryMethod(basedir,
     589              :                                                 compression_algorithm,
     590              :                                                 compresslevel,
     591            6 :                                                 stream.do_sync);
     592            6 :     stream.partial_suffix = ".partial";
     593            6 :     stream.replication_slot = replication_slot;
     594            6 :     stream.sysidentifier = sysidentifier;
     595              : 
     596            6 :     ReceiveXlogStream(conn, &stream);
     597              : 
     598            6 :     if (!stream.walmethod->ops->finish(stream.walmethod))
     599              :     {
     600            0 :         pg_log_info("could not finish writing WAL files: %m");
     601            0 :         return;
     602              :     }
     603              : 
     604            6 :     PQfinish(conn);
     605            6 :     conn = NULL;
     606              : 
     607            6 :     stream.walmethod->ops->free(stream.walmethod);
     608              : }
     609              : 
     610              : /*
     611              :  * When SIGINT/SIGTERM are caught, just tell the system to exit at the next
     612              :  * possible moment.
     613              :  */
     614              : #ifndef WIN32
     615              : 
     616              : static void
     617            0 : sigexit_handler(SIGNAL_ARGS)
     618              : {
     619            0 :     time_to_stop = true;
     620            0 : }
     621              : #endif
     622              : 
     623              : int
     624           17 : main(int argc, char **argv)
     625              : {
     626              :     static struct option long_options[] = {
     627              :         {"help", no_argument, NULL, '?'},
     628              :         {"version", no_argument, NULL, 'V'},
     629              :         {"directory", required_argument, NULL, 'D'},
     630              :         {"dbname", required_argument, NULL, 'd'},
     631              :         {"endpos", required_argument, NULL, 'E'},
     632              :         {"host", required_argument, NULL, 'h'},
     633              :         {"port", required_argument, NULL, 'p'},
     634              :         {"username", required_argument, NULL, 'U'},
     635              :         {"no-loop", no_argument, NULL, 'n'},
     636              :         {"no-password", no_argument, NULL, 'w'},
     637              :         {"password", no_argument, NULL, 'W'},
     638              :         {"status-interval", required_argument, NULL, 's'},
     639              :         {"slot", required_argument, NULL, 'S'},
     640              :         {"verbose", no_argument, NULL, 'v'},
     641              :         {"compress", required_argument, NULL, 'Z'},
     642              : /* action */
     643              :         {"create-slot", no_argument, NULL, 1},
     644              :         {"drop-slot", no_argument, NULL, 2},
     645              :         {"if-not-exists", no_argument, NULL, 3},
     646              :         {"synchronous", no_argument, NULL, 4},
     647              :         {"no-sync", no_argument, NULL, 5},
     648              :         {NULL, 0, NULL, 0}
     649              :     };
     650              : 
     651              :     int         c;
     652              :     int         option_index;
     653              :     char       *db_name;
     654              :     uint32      hi,
     655              :                 lo;
     656              :     pg_compress_specification compression_spec;
     657           17 :     char       *compression_detail = NULL;
     658           17 :     char       *compression_algorithm_str = "none";
     659           17 :     char       *error_detail = NULL;
     660              : 
     661           17 :     pg_logging_init(argv[0]);
     662           17 :     progname = get_progname(argv[0]);
     663           17 :     set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_basebackup"));
     664              : 
     665           17 :     if (argc > 1)
     666              :     {
     667           16 :         if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
     668              :         {
     669            1 :             usage();
     670            1 :             exit(0);
     671              :         }
     672           15 :         else if (strcmp(argv[1], "-V") == 0 ||
     673           15 :                  strcmp(argv[1], "--version") == 0)
     674              :         {
     675            1 :             puts("pg_receivewal (PostgreSQL) " PG_VERSION);
     676            1 :             exit(0);
     677              :         }
     678              :     }
     679              : 
     680           66 :     while ((c = getopt_long(argc, argv, "d:D:E:h:np:s:S:U:vwWZ:",
     681           66 :                             long_options, &option_index)) != -1)
     682              :     {
     683           52 :         switch (c)
     684              :         {
     685            0 :             case 'd':
     686            0 :                 connection_string = pg_strdup(optarg);
     687            0 :                 break;
     688           11 :             case 'D':
     689           11 :                 basedir = pg_strdup(optarg);
     690           11 :                 break;
     691            7 :             case 'E':
     692            7 :                 if (sscanf(optarg, "%X/%08X", &hi, &lo) != 2)
     693            0 :                     pg_fatal("could not parse end position \"%s\"", optarg);
     694            7 :                 endpos = ((uint64) hi) << 32 | lo;
     695            7 :                 break;
     696            0 :             case 'h':
     697            0 :                 dbhost = pg_strdup(optarg);
     698            0 :                 break;
     699            7 :             case 'n':
     700            7 :                 noloop = true;
     701            7 :                 break;
     702            0 :             case 'p':
     703            0 :                 dbport = pg_strdup(optarg);
     704            0 :                 break;
     705            0 :             case 's':
     706            0 :                 if (!option_parse_int(optarg, "-s/--status-interval", 0,
     707              :                                       INT_MAX / 1000,
     708              :                                       &standby_message_timeout))
     709            0 :                     exit(1);
     710            0 :                 standby_message_timeout *= 1000;
     711            0 :                 break;
     712            5 :             case 'S':
     713            5 :                 replication_slot = pg_strdup(optarg);
     714            5 :                 break;
     715            0 :             case 'U':
     716            0 :                 dbuser = pg_strdup(optarg);
     717            0 :                 break;
     718            7 :             case 'v':
     719            7 :                 verbose++;
     720            7 :                 break;
     721            0 :             case 'w':
     722            0 :                 dbgetpassword = -1;
     723            0 :                 break;
     724            0 :             case 'W':
     725            0 :                 dbgetpassword = 1;
     726            0 :                 break;
     727            3 :             case 'Z':
     728            3 :                 parse_compress_options(optarg, &compression_algorithm_str,
     729              :                                        &compression_detail);
     730            3 :                 break;
     731            3 :             case 1:
     732            3 :                 do_create_slot = true;
     733            3 :                 break;
     734            2 :             case 2:
     735            2 :                 do_drop_slot = true;
     736            2 :                 break;
     737            0 :             case 3:
     738            0 :                 slot_exists_ok = true;
     739            0 :                 break;
     740            2 :             case 4:
     741            2 :                 synchronous = true;
     742            2 :                 break;
     743            4 :             case 5:
     744            4 :                 do_sync = false;
     745            4 :                 break;
     746            1 :             default:
     747              :                 /* getopt_long already emitted a complaint */
     748            1 :                 pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     749            1 :                 exit(1);
     750              :         }
     751              :     }
     752              : 
     753              :     /*
     754              :      * Any non-option arguments?
     755              :      */
     756           14 :     if (optind < argc)
     757              :     {
     758            0 :         pg_log_error("too many command-line arguments (first is \"%s\")",
     759              :                      argv[optind]);
     760            0 :         pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     761            0 :         exit(1);
     762              :     }
     763              : 
     764           14 :     if (do_drop_slot && do_create_slot)
     765              :     {
     766            1 :         pg_log_error("cannot use --create-slot together with --drop-slot");
     767            1 :         pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     768            1 :         exit(1);
     769              :     }
     770              : 
     771           13 :     if (replication_slot == NULL && (do_drop_slot || do_create_slot))
     772              :     {
     773              :         /* translator: %s is an option name */
     774            1 :         pg_log_error("%s needs a slot to be specified using --slot",
     775              :                      do_drop_slot ? "--drop-slot" : "--create-slot");
     776            1 :         pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     777            1 :         exit(1);
     778              :     }
     779              : 
     780           12 :     if (synchronous && !do_sync)
     781              :     {
     782            1 :         pg_log_error("cannot use --synchronous together with --no-sync");
     783            1 :         pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     784            1 :         exit(1);
     785              :     }
     786              : 
     787              :     /*
     788              :      * Required arguments
     789              :      */
     790           11 :     if (basedir == NULL && !do_drop_slot && !do_create_slot)
     791              :     {
     792            1 :         pg_log_error("no target directory specified");
     793            1 :         pg_log_error_hint("Try \"%s --help\" for more information.", progname);
     794            1 :         exit(1);
     795              :     }
     796              : 
     797              :     /*
     798              :      * Compression options
     799              :      */
     800           10 :     if (!parse_compress_algorithm(compression_algorithm_str,
     801              :                                   &compression_algorithm))
     802            0 :         pg_fatal("unrecognized compression algorithm: \"%s\"",
     803              :                  compression_algorithm_str);
     804              : 
     805           10 :     parse_compress_specification(compression_algorithm, compression_detail,
     806              :                                  &compression_spec);
     807           10 :     error_detail = validate_compress_specification(&compression_spec);
     808           10 :     if (error_detail != NULL)
     809            1 :         pg_fatal("invalid compression specification: %s",
     810              :                  error_detail);
     811              : 
     812              :     /* Extract the compression level */
     813            9 :     compresslevel = compression_spec.level;
     814              : 
     815            9 :     if (compression_algorithm == PG_COMPRESSION_ZSTD)
     816            0 :         pg_fatal("compression with %s is not yet supported", "ZSTD");
     817              : 
     818              :     /*
     819              :      * Check existence of destination folder.
     820              :      */
     821            9 :     if (!do_drop_slot && !do_create_slot)
     822              :     {
     823            7 :         DIR        *dir = get_destination_dir(basedir);
     824              : 
     825            7 :         close_destination_dir(dir, basedir);
     826              :     }
     827              : 
     828              :     /*
     829              :      * Obtain a connection before doing anything.
     830              :      */
     831            9 :     conn = GetConnection();
     832            9 :     if (!conn)
     833              :         /* error message already written in GetConnection() */
     834            0 :         exit(1);
     835            9 :     atexit(disconnect_atexit);
     836              : 
     837              :     /*
     838              :      * Trap signals.  (Don't do this until after the initial password prompt,
     839              :      * if one is needed, in GetConnection.)
     840              :      */
     841              : #ifndef WIN32
     842            9 :     pqsignal(SIGINT, sigexit_handler);
     843            9 :     pqsignal(SIGTERM, sigexit_handler);
     844              : #endif
     845              : 
     846              :     /*
     847              :      * Run IDENTIFY_SYSTEM to make sure we've successfully have established a
     848              :      * replication connection and haven't connected using a database specific
     849              :      * connection.
     850              :      */
     851            9 :     if (!RunIdentifySystem(conn, NULL, NULL, NULL, &db_name))
     852            0 :         exit(1);
     853              : 
     854              :     /*
     855              :      * Check that there is a database associated with connection, none should
     856              :      * be defined in this context.
     857              :      */
     858            9 :     if (db_name)
     859            0 :         pg_fatal("replication connection using slot \"%s\" is unexpectedly database specific",
     860              :                  replication_slot);
     861              : 
     862              :     /*
     863              :      * Set umask so that directories/files are created with the same
     864              :      * permissions as directories/files in the source data directory.
     865              :      *
     866              :      * pg_mode_mask is set to owner-only by default and then updated in
     867              :      * GetConnection() where we get the mode from the server-side with
     868              :      * RetrieveDataDirCreatePerm() and then call SetDataDirectoryCreatePerm().
     869              :      */
     870            9 :     umask(pg_mode_mask);
     871              : 
     872              :     /*
     873              :      * Drop a replication slot.
     874              :      */
     875            9 :     if (do_drop_slot)
     876              :     {
     877            1 :         if (verbose)
     878            0 :             pg_log_info("dropping replication slot \"%s\"", replication_slot);
     879              : 
     880            1 :         if (!DropReplicationSlot(conn, replication_slot))
     881            0 :             exit(1);
     882            1 :         exit(0);
     883              :     }
     884              : 
     885              :     /* Create a replication slot */
     886            8 :     if (do_create_slot)
     887              :     {
     888            1 :         if (verbose)
     889            0 :             pg_log_info("creating replication slot \"%s\"", replication_slot);
     890              : 
     891            1 :         if (!CreateReplicationSlot(conn, replication_slot, NULL, false, true, false,
     892              :                                    slot_exists_ok, false, false))
     893            0 :             exit(1);
     894            1 :         exit(0);
     895              :     }
     896              : 
     897              :     /* determine remote server's xlog segment size */
     898            7 :     if (!RetrieveWalSegSize(conn))
     899            0 :         exit(1);
     900              : 
     901              :     /*
     902              :      * Don't close the connection here so that subsequent StreamLog() can
     903              :      * reuse it.
     904              :      */
     905              : 
     906              :     while (true)
     907              :     {
     908            7 :         StreamLog();
     909            7 :         if (time_to_stop)
     910              :         {
     911              :             /*
     912              :              * We've been Ctrl-C'ed or end of streaming position has been
     913              :              * willingly reached, so exit without an error code.
     914              :              */
     915            6 :             exit(0);
     916              :         }
     917            1 :         else if (noloop)
     918            1 :             pg_fatal("disconnected");
     919              :         else
     920              :         {
     921              :             /* translator: check source for value for %d */
     922            0 :             pg_log_info("disconnected; waiting %d seconds to try again",
     923              :                         RECONNECT_SLEEP_TIME);
     924            0 :             pg_usleep(RECONNECT_SLEEP_TIME * 1000000);
     925              :         }
     926              :     }
     927              : }
        

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