The virCommandNewArgs() method would free the virCommandPtr
if it failed to add the args. This meant errors reported in
virCommandAddArgSet() were lost. Simply removing the check
for errors from the constructor means they can be reported
correctly later
The virCommandAddEnvPassCommon() method failed to check for
errors before reallocating the cmd->env array, causing a
potential SEGV if cmd was NULL
The virCommandAddArgSet() method needs to validate that at
least 1 element in 'val's parameter is non-NULL, otherwise
code like
cmd = virCommandNew(binary)
virCommandAddAtg(cmd, "foo")
Would end up trying todo execve("foo"), if binary was
NULL.
clang had 5 reports against virCommand; three were false positives
(a NULL deref in ProcessIO solved by sa_assert, and two uninitialized
memory operations solved by adding an initializer), but two were real.
* src/util/command.c (virCommandProcessIO): Fix real bug of
possible NULL dereference. Teach clang that buf is never NULL.
(virCommandRun): Teach clang that infd is only ever accessed when
initialized.
Guarantee that outbuf/errbuf are allocated on success, even if to the
empty string. Caller always has to free the result, and empty output
check requires checking if *outbuf=='\0'. Makes the API easier to use
safely. Failure is best effort allocation (some paths, like
out-of-memory, cannot allocate a buffer, but most do), so caller must
free buffer on failure.
* docs/internals/command.html.in: Update documentation.
* src/util/command.c (virCommandSetOutputBuffer)
(virCommandSetErrorBuffer, virCommandProcessIO) Guarantee empty
string on no output.
* tests/commandtest.c (test17): New test.
* docs/internals/command.html.in: Better documentation of buffer
vs. fd considerations.
* src/util/command.c (virCommandRunAsync): Reject raw execution
with string io.
(virCommandRun): Reject execution with user-specified fds not
visiting a regular file.
"virCommandRun": if "cmd->outbuf" or "cmd->errbuf" is NULL,
libvirtd will be crashed when trying to start a qemu domain
(which invokes "virCommandRun"), it caused by we try to use
"*cmd->outbuf" and "*cmd->errbuf" regardless of cmd->outbuf
or cmd->errbuf is NULL.
* src/util/command.c (virCommandRun)
This introduces a new set of APIs in src/util/command.h
to use for invoking commands. This is intended to replace
all current usage of virRun and virExec variants, with a
more flexible and less error prone API.
* src/util/command.c: New file.
* src/util/command.h: New header.
* src/Makefile.am (UTIL_SOURCES): Build it.
* src/libvirt_private.syms: Export symbols internally.
* tests/commandtest.c: New test.
* tests/Makefile.am (check_PROGRAMS): Run it.
* tests/commandhelper.c: Auxiliary program.
* tests/commanddata/test2.log - test15.log: New expected outputs.
* cfg.mk (useless_free_options): Add virCommandFree.
(msg_gen_function): Add virCommandError.
* po/POTFILES.in: New translation.
* .x-sc_avoid_write: Add exemption.
* tests/.gitignore: Ignore new built file.
