| 1 | #! @PERL@ |
| 2 | ### |
| 3 | ### Synchronize snapshot with remotely mounted filesystem |
| 4 | ### |
| 5 | ### (c) 2011 Mark Wooding |
| 6 | ### |
| 7 | |
| 8 | ###----- Licensing notice --------------------------------------------------- |
| 9 | ### |
| 10 | ### This file is part of the distorted.org.uk backup suite. |
| 11 | ### |
| 12 | ### distorted-backup is free software; you can redistribute it and/or modify |
| 13 | ### it under the terms of the GNU General Public License as published by |
| 14 | ### the Free Software Foundation; either version 2 of the License, or |
| 15 | ### (at your option) any later version. |
| 16 | ### |
| 17 | ### distorted-backup is distributed in the hope that it will be useful, |
| 18 | ### but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | ### GNU General Public License for more details. |
| 21 | ### |
| 22 | ### You should have received a copy of the GNU General Public License along |
| 23 | ### with distorted-backup; if not, write to the Free Software Foundation, |
| 24 | ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 25 | |
| 26 | use Socket; |
| 27 | |
| 28 | ###-------------------------------------------------------------------------- |
| 29 | ### Utilities. |
| 30 | |
| 31 | (our $QUIS = $0) =~ s:^.*/::; |
| 32 | sub whine ($) { my ($msg) = @_; print STDERR "$QUIS: $msg\n"; } |
| 33 | sub fail ($) { my ($msg) = @_; whine $msg; exit $! || ($? >> 8) || 255; } |
| 34 | |
| 35 | our @CLEANUP = (); |
| 36 | sub cleanup (&) { my ($func) = @_; unshift @CLEAUP, $func; } |
| 37 | END { local $?; for my $func (@CLEANUP) { &$func } } |
| 38 | |
| 39 | sub gripelist ($@) { |
| 40 | my ($gripe, @things) = @_; |
| 41 | fail "$gripe: " . join(", ", @things) if @things; |
| 42 | } |
| 43 | |
| 44 | ###-------------------------------------------------------------------------- |
| 45 | ### Parse command line. |
| 46 | |
| 47 | our $USAGE = "usage: $QUIS DEVICE [KEY=VALUE ...]"; |
| 48 | sub version { print "$QUIS, version 1.0.0\n"; } |
| 49 | sub help { |
| 50 | print <<EOF; |
| 51 | $USAGE |
| 52 | |
| 53 | Option keys: |
| 54 | dir=MOUNTPT Mount point of filesystem on remote host [required]. |
| 55 | host=[USER@]NAME Name or address of remote host [required]. |
| 56 | op=OPERATION `snap' to create snapshot, or `unsnap' to remove. |
| 57 | rfreezefs=PATH Location of `rfreezefs' program on remote host. |
| 58 | ssh=PATH Location of remote-shell program on local host. |
| 59 | subtype=TYPE Type of snapshot to create [required]. |
| 60 | |
| 61 | Other option keys are passed to the underlying snapshot TYPE. |
| 62 | EOF |
| 63 | } |
| 64 | @ARGV >= 1 or do { print STDERR $USAGE, "\n"; exit 1; }; |
| 65 | $ARGV[0] eq "-v" || $ARGV[0] eq "--version" and do { version; exit; }; |
| 66 | $ARGV[0] eq "-h" || $ARGV[0] eq "--help" and do { version; help; exit; }; |
| 67 | |
| 68 | our $DEV = shift; |
| 69 | our %OPT = ( dir => undef, |
| 70 | host => undef, |
| 71 | op => "snap", |
| 72 | rfreezefs => "rfreezefs", |
| 73 | ssh => "ssh", |
| 74 | subtype => undef ); |
| 75 | our @PASS = (); |
| 76 | |
| 77 | for my $i (@ARGV) { |
| 78 | $i =~ /^([^\s=]+)=(.*)$/ or fail "malformed option `$i'"; |
| 79 | my ($k, $v) = ($1, $2); |
| 80 | if ($k =~ /^([^.]+)\.(.+)$/) { |
| 81 | if ($2 eq "rfreezefs") { $k = $1; } |
| 82 | } |
| 83 | if (exists $OPT{$k}) { $OPT{$k} = $v; } |
| 84 | else { push @PASS, $i; } |
| 85 | } |
| 86 | gripelist "missing arguments", grep { !defined $OPT{$_} } keys %OPT; |
| 87 | |
| 88 | (my $host = $OPT{host}) =~ s/^.*@//; |
| 89 | my $addr = inet_aton $host or fail "failed to resolve `$OPT{host}'"; |
| 90 | |
| 91 | ###-------------------------------------------------------------------------- |
| 92 | ### Remove a snapshot if requested. |
| 93 | |
| 94 | if ($OPT{op} eq "unsnap") { |
| 95 | |
| 96 | ## This doesn't require negotiation with the remote end. |
| 97 | if ($OPT{unsnap}) { |
| 98 | exec "snap.$OPT{subtype}", $DEV, "op=unsnap", @PASS; |
| 99 | fail "exec snap.$OPT{subtype}: $!"; |
| 100 | } |
| 101 | |
| 102 | } elsif ($OPT{op} ne "snap") { |
| 103 | fail "unknown operation `$OPT{op}'"; |
| 104 | } |
| 105 | |
| 106 | ###-------------------------------------------------------------------------- |
| 107 | ### Run `rfreezefs' on the remote host and collect information. |
| 108 | |
| 109 | (my $dir = $OPT{dir}) =~ s/\'/'\\''/g; |
| 110 | open SSH, "-|", $OPT{ssh}, $OPT{host}, "$OPT{rfreezefs} -n '$dir'" |
| 111 | or fail "open(ssh): $!"; |
| 112 | cleanup { close SSH }; |
| 113 | |
| 114 | our %INF = ( PORT => undef ); |
| 115 | our %TOK = (); |
| 116 | our %RTOK = (); |
| 117 | our $PORT = undef; |
| 118 | |
| 119 | while (<SSH>) { |
| 120 | my @f = split; |
| 121 | if ($f[0] eq "PORT") { $INF{$f[0]} = $f[1]; } |
| 122 | elsif ($f[1] eq "TOKEN") { $TOK{$f[1]} = $f[2]; $RTOK{$f[2]} = $f[1]; } |
| 123 | elsif ($f[0] eq "READY") { last; } |
| 124 | } |
| 125 | |
| 126 | gripelist "missing information", grep { !defined $INF{$_} } keys %INF; |
| 127 | gripelist "missing tokens", |
| 128 | grep { !exists $TOK{$_} } "FREEZE", "FROZEN", "THAW", "THAWED"; |
| 129 | |
| 130 | ###-------------------------------------------------------------------------- |
| 131 | ### Create the snapshot. |
| 132 | |
| 133 | ## Connect to the socket. |
| 134 | socket SK, PF_INET, SOCK_STREAM, 0 or fail "socket: $!"; |
| 135 | cleanup { close SK }; |
| 136 | select SK; $| = 1; |
| 137 | connect SK, sockaddr_in($INF{PORT}, $addr) or fail "connect: $!"; |
| 138 | |
| 139 | ## Communication with the server. |
| 140 | sub rffscmd ($;$) { |
| 141 | my ($cmd, $rpl) = @_; |
| 142 | print SK $TOK{$cmd}, "\n" or fail "write <$cmd>: $!"; |
| 143 | if ($rpl) { |
| 144 | chomp (my $line = <SK>); |
| 145 | if ($line ne $TOK{$rpl}) { |
| 146 | my $what = exists $RTOK{$line} ? "<$RTOK{$line}>" : "`$line'"; |
| 147 | fail "unexpected response $what to <$cmd>"; |
| 148 | } |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | ## Freeze the remote filesystem. |
| 153 | rffscmd(FREEZE, FROZEN); |
| 154 | |
| 155 | ## Create the snapshot locally using the appropriate mechanism. This will |
| 156 | ## print the snapshot device name. |
| 157 | my $rc = system "snap.$OPT{subtype}", $DEV, @PASS; |
| 158 | $rc and fail "snap.$OPT{subtype} failed (rc = $rc)"; |
| 159 | |
| 160 | ## Discard the snapshot again if anything goes wrong. |
| 161 | cleanup { |
| 162 | if ($?) { |
| 163 | my $rc = system "snap.$OPT{subtype}", $DEV, "unsnap", @PASS; |
| 164 | $rc and |
| 165 | whine "snap.$OPT{subtype} failed to unsnap (rc = $rc) " . |
| 166 | "while recovering"; |
| 167 | } |
| 168 | }; |
| 169 | |
| 170 | ## Thaw the remote filesystem. |
| 171 | rffscmd(THAW, THAWED); |
| 172 | |
| 173 | ###----- That's all, folks -------------------------------------------------- |
| 174 | |
| 175 | exit 0; |