diff options
Diffstat (limited to 'daemon/compress.c')
| -rw-r--r-- | daemon/compress.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/daemon/compress.c b/daemon/compress.c new file mode 100644 index 00000000..d08d3cc9 --- /dev/null +++ b/daemon/compress.c @@ -0,0 +1,207 @@ +/* libguestfs - the guestfsd daemon + * Copyright (C) 2011 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <fcntl.h> + +#include "guestfs_protocol.h" +#include "daemon.h" +#include "actions.h" + +/* Has one FileOut parameter. */ +static int +do_compressX_out (const char *file, const char *filter, int is_device) +{ + int r; + FILE *fp; + char *cmd; + char buf[GUESTFS_MAX_CHUNK_SIZE]; + + /* The command will look something like: + * gzip -c /sysroot%s # file + * or: + * gzip -c < %s # device + * + * We have to quote the file or device name. + * + * The unnecessary redirect for devices is there because lzop + * unhelpfully refuses to compress anything that isn't a regular + * file. + */ + if (!is_device) { + if (asprintf_nowarn (&cmd, "%s %R", filter, file) == -1) { + reply_with_perror ("asprintf"); + return -1; + } + } else { + if (asprintf_nowarn (&cmd, "%s < %Q", filter, file) == -1) { + reply_with_perror ("asprintf"); + return -1; + } + } + + if (verbose) + fprintf (stderr, "%s\n", cmd); + + fp = popen (cmd, "r"); + if (fp == NULL) { + reply_with_perror ("%s", cmd); + free (cmd); + return -1; + } + free (cmd); + + /* Now we must send the reply message, before the file contents. After + * this there is no opportunity in the protocol to send any error + * message back. Instead we can only cancel the transfer. + */ + reply (NULL, NULL); + + while ((r = fread (buf, 1, sizeof buf, fp)) > 0) { + if (send_file_write (buf, r) < 0) { + pclose (fp); + return -1; + } + } + + if (ferror (fp)) { + perror (file); + send_file_end (1); /* Cancel. */ + pclose (fp); + return -1; + } + + if (pclose (fp) != 0) { + perror (file); + send_file_end (1); /* Cancel. */ + return -1; + } + + if (send_file_end (0)) /* Normal end of file. */ + return -1; + + return 0; +} + +#define CHECK_SUPPORTED(prog) \ + if (!prog_exists (prog)) { \ + /* note: substring "not supported" must appear in this error */ \ + reply_with_error ("compression type %s is not supported", prog); \ + return -1; \ + } + +static int +get_filter (const char *ctype, int level, char *ret, size_t n) +{ + if (STREQ (ctype, "compress")) { + CHECK_SUPPORTED ("compress"); + if (level != -1) { + reply_with_error ("compress: cannot use optional level parameter with this compression type"); + return -1; + } + snprintf (ret, n, "compress -c"); + return 0; + } + else if (STREQ (ctype, "gzip")) { + CHECK_SUPPORTED ("gzip"); + if (level == -1) + snprintf (ret, n, "gzip -c"); + else if (level >= 1 && level <= 9) + snprintf (ret, n, "gzip -c -%d", level); + else { + reply_with_error ("gzip: incorrect value for level parameter"); + return -1; + } + return 0; + } + else if (STREQ (ctype, "bzip2")) { + CHECK_SUPPORTED ("bzip2"); + if (level == -1) + snprintf (ret, n, "bzip2 -c"); + else if (level >= 1 && level <= 9) + snprintf (ret, n, "bzip2 -c -%d", level); + else { + reply_with_error ("bzip2: incorrect value for level parameter"); + return -1; + } + return 0; + } + else if (STREQ (ctype, "xz")) { + CHECK_SUPPORTED ("xz"); + if (level == -1) + snprintf (ret, n, "xz -c"); + else if (level >= 0 && level <= 9) + snprintf (ret, n, "xz -c -%d", level); + else { + reply_with_error ("xz: incorrect value for level parameter"); + return -1; + } + return 0; + } + else if (STREQ (ctype, "lzop")) { + CHECK_SUPPORTED ("lzop"); + if (level == -1) + snprintf (ret, n, "lzop -c"); + else if (level >= 1 && level <= 9) + snprintf (ret, n, "lzop -c -%d", level); + else { + reply_with_error ("lzop: incorrect value for level parameter"); + return -1; + } + return 0; + } + + reply_with_error ("unknown compression type"); + return -1; +} + +/* Has one FileOut parameter. */ +/* Takes optional arguments, consult optargs_bitmask. */ +int +do_compress_out (const char *ctype, const char *file, int level) +{ + char filter[64]; + + if (!(optargs_bitmask & GUESTFS_COMPRESS_OUT_LEVEL_BITMASK)) + level = -1; + + if (get_filter (ctype, level, filter, sizeof filter) == -1) + return -1; + + return do_compressX_out (file, filter, 0); +} + +/* Has one FileOut parameter. */ +/* Takes optional arguments, consult optargs_bitmask. */ +int +do_compress_device_out (const char *ctype, const char *file, int level) +{ + char filter[64]; + + if (!(optargs_bitmask & GUESTFS_COMPRESS_DEVICE_OUT_LEVEL_BITMASK)) + level = -1; + + if (get_filter (ctype, level, filter, sizeof filter) == -1) + return -1; + + return do_compressX_out (file, filter, 1); +} |