X-Git-Url: https://git.proxmox.com/?p=pve-common.git;a=blobdiff_plain;f=src%2FPVE%2FTools.pm;h=1a342ee04cc660f88dd567d4442ba895be5a0f43;hp=0c6dde6570bffad93003d95d47fc3a4c64f7b8d4;hb=771d18f5c7be2055f0c9012f7f921f6d5f6337db;hpb=b2613777279f5a55b1ce2b460768943d946ccb9d

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index 0c6dde6..1a342ee 100644
--- a/src/PVE/Tools.pm
+++ b/src/PVE/Tools.pm
@@ -18,7 +18,7 @@ use Encode;
 use Digest::SHA;
 use Text::ParseWords;
 use String::ShellQuote;
-use Time::HiRes qw(usleep gettimeofday tv_interval);
+use Time::HiRes qw(usleep gettimeofday tv_interval alarm);
 
 # avoid warning when parsing long hex values with hex()
 no warnings 'portable'; # Support for 64-bit ints required
@@ -63,35 +63,43 @@ our $IPV6RE = "(?:" .
     "(?:(?:(?:(?:$IPV6H16:){0,5}$IPV6H16)?::" .            ")$IPV6H16)|" .
     "(?:(?:(?:(?:$IPV6H16:){0,6}$IPV6H16)?::" .                    ")))";
 
+use constant (CLONE_NEWNS   => 0x00020000,
+              CLONE_NEWUTS  => 0x04000000,
+              CLONE_NEWIPC  => 0x08000000,
+              CLONE_NEWUSER => 0x10000000,
+              CLONE_NEWPID  => 0x20000000,
+              CLONE_NEWNET  => 0x40000000);
+
 sub run_with_timeout {
     my ($timeout, $code, @param) = @_;
 
     die "got timeout\n" if $timeout <= 0;
 
-    my $prev_alarm;
+    my $prev_alarm = alarm 0; # suspend outer alarm early
 
     my $sigcount = 0;
 
     my $res;
 
-    local $SIG{ALRM} = sub { $sigcount++; }; # catch alarm outside eval
-
     eval {
 	local $SIG{ALRM} = sub { $sigcount++; die "got timeout\n"; };
 	local $SIG{PIPE} = sub { $sigcount++; die "broken pipe\n" };
 	local $SIG{__DIE__};   # see SA bug 4631
 
-	$prev_alarm = alarm($timeout);
+	alarm($timeout);
 
-	$res = &$code(@param);
+	eval { $res = &$code(@param); };
 
 	alarm(0); # avoid race conditions
+
+	die $@ if $@;
     };
 
     my $err = $@;
 
-    alarm($prev_alarm) if defined($prev_alarm);
+    alarm $prev_alarm;
 
+    # this shouldn't happen anymore?
     die "unknown error" if $sigcount && !$err; # seems to happen sometimes
 
     die $err if $err;
@@ -240,13 +248,52 @@ sub safe_read_from {
     return $input;
 }
 
+# The $cmd parameter can be:
+#  -) a string
+#    This is generally executed by passing it to the shell with the -c option.
+#    However, it can be executed in one of two ways, depending on whether
+#    there's a pipe involved:
+#      *) with pipe: passed explicitly to bash -c, prefixed with:
+#          set -o pipefail &&
+#      *) without a pipe: passed to perl's open3 which uses 'sh -c'
+#      (Note that this may result in two different syntax requirements!)
+#      FIXME?
+#  -) an array of arguments (strings)
+#    Will be executed without interference from a shell. (Parameters are passed
+#    as is, no escape sequences of strings will be touched.)
+#  -) an array of arrays
+#    Each array represents a command, and each command's output is piped into
+#    the following command's standard input.
+#    For this a shell command string is created with pipe symbols between each
+#    command.
+#    Each command is a list of strings meant to end up in the final command
+#    unchanged. In order to achieve this, every argument is shell-quoted.
+#    Quoting can be disabled for a particular argument by turning it into a
+#    reference, this allows inserting arbitrary shell options.
+#    For instance: the $cmd [ [ 'echo', 'hello', \'>/dev/null' ] ] will not
+#    produce any output, while the $cmd [ [ 'echo', 'hello', '>/dev/null' ] ]
+#    will literally print: hello >/dev/null
 sub run_command {
     my ($cmd, %param) = @_;
 
     my $old_umask;
     my $cmdstr;
 
-    if (!ref($cmd)) {
+    if (my $ref = ref($cmd)) {
+	if (ref($cmd->[0])) {
+	    $cmdstr = 'set -o pipefail && ';
+	    my $pipe = '';
+	    foreach my $command (@$cmd) {
+		# concatenate quoted parameters
+		# strings which are passed by reference are NOT shell quoted
+		$cmdstr .= $pipe .  join(' ', map { ref($_) ? $$_ : shellquote($_) } @$command);
+		$pipe = ' | ';
+	    }
+	    $cmd = [ '/bin/bash', '-c', "set -o pipefail && $cmdstr" ];
+	} else {
+	    $cmdstr = cmd2string($cmd);
+	}
+    } else {
 	$cmdstr = $cmd;
 	if ($cmd =~ m/\|/) {
 	    # see 'man bash' for option pipefail
@@ -254,8 +301,6 @@ sub run_command {
 	} else {
 	    $cmd = [ $cmd ];
 	}
-    } else {
-	$cmdstr = cmd2string($cmd);
     }
 
     my $errmsg;
@@ -1115,4 +1160,9 @@ sub parse_host_and_port {
     return; # nothing
 }
 
+sub unshare {
+    my ($flags) = @_;
+    syscall 272, $flags;
+}
+
 1;