On Fri, Sep 11, 2009 at 02:39:24PM +0100, Matthew Booth wrote:
echo_daemon is a simple echo which can be used to test connectivity between the client and daemon. --- daemon/Makefile.am | 1 + daemon/echo_daemon.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++ po/POTFILES.in | 1 + src/MAX_PROC_NR | 2 +- src/generator.ml | 7 +++++ 5 files changed, 76 insertions(+), 1 deletions(-) create mode 100644 daemon/echo_daemon.c
diff --git a/daemon/Makefile.am b/daemon/Makefile.am index 83ee408..ae74699 100644 --- a/daemon/Makefile.am +++ b/daemon/Makefile.am @@ -36,6 +36,7 @@ guestfsd_SOURCES = \ dmesg.c \ dropcaches.c \ du.c \ + echo_daemon.c \ ext2.c \ fallocate.c \ file.c \ diff --git a/daemon/echo_daemon.c b/daemon/echo_daemon.c new file mode 100644 index 0000000..dbede2f --- /dev/null +++ b/daemon/echo_daemon.c @@ -0,0 +1,66 @@ +/* libguestfs - the guestfsd daemon + * Copyright (C) 2009 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 <string.h> + +#include "actions.h" + +char * +do_echo_daemon (char *const *argv) +{ + char *out = NULL; + size_t out_len = 0; + + /* Iterate over argv entries until reaching the NULL terminator */ + while (*argv) { + char add_space = 0; + + /* Store the end of current output */ + size_t out_end = out_len; + + /* Calculate the new output size */ + size_t arg_len = strlen(*argv); + out_len += arg_len; + + /* We will prepend a space if this isn't the first argument added */ + if (NULL != out) { + out_len++; + add_space = 1; + } + + /* Make the output buffer big enough for the string and its terminator */ + out = realloc (out, out_len + 1);
In the daemon we have to check the return value from malloc/realloc very carefully. The reason is that the daemon runs in limited space.
+ /* Prepend a space if required */ + if (add_space) { + out[out_end++] = ' '; + } + + /* Copy the argument to the output */ + memcpy(&out[out_end], *argv, arg_len); + + argv++; + } + + /* NULL terminate the output */ + out[out_len] = '\0'; + + return out; +} diff --git a/po/POTFILES.in b/po/POTFILES.in index 1b2f82a..44e472b 100644 --- a/po/POTFILES.in +++ b/po/POTFILES.in @@ -12,6 +12,7 @@ daemon/dir.c daemon/dmesg.c daemon/dropcaches.c daemon/du.c +daemon/echo_daemon.c daemon/ext2.c daemon/fallocate.c daemon/file.c diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR index 205a12b..6bb2f98 100644 --- a/src/MAX_PROC_NR +++ b/src/MAX_PROC_NR @@ -1 +1 @@ -194 +195 diff --git a/src/generator.ml b/src/generator.ml index 439c9c4..f820e1f 100755 --- a/src/generator.ml +++ b/src/generator.ml @@ -3595,6 +3595,13 @@ This loads a kernel module in the appliance. The kernel module must have been whitelisted when libguestfs was built (see C<appliance/kmod.whitelist.in> in the source).");
+ ("echo_daemon", (RString "output", [StringList "words"]), 195, [], + [InitNone, Always, TestRun [["echo_daemon"; "\"This is a test\""]]],
This should test the return value using TestOutput. Also note that this is passing a list of length four. (Handling of lists in the test code is very hairy).
+ "echo arguments back to the client", + "\ +This commands works much like the unix echo command. It returns its arguments as +a string.");
A better description: This command concatenates the list of C<words> passed with single spaces between them and returns the resulting string. You can use this to test the connection through to the daemon. See also C<guestfs_ping_daemon>. Rich. -- Richard Jones, Emerging Technologies, Red Hat http://et.redhat.com/~rjones virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://et.redhat.com/~rjones/virt-df/