[lxc-devel] [PATCH] Set default paths for unprivileged use

[Serge Hallyn]

Quoting Stéphane Graber (stgraber at ubuntu.com):
> When running unprivileged (euid != 0), LXC will now use the following paths:
>  - Default lxc path: ~/.local/share/lxc/
>  - Default config path: ~/.config/lxc/lxc.conf
> 
> Those two paths are based on standard XDG paths (though ignoring all the
> possible override paths for now at least) and so probably don't need to
> be configurable at build time.
> 
> Signed-off-by: Stéphane Graber <stgraber at ubuntu.com>

Two comments on freeing user_lxc_path:

> ---
>  src/lxc/utils.c | 37 ++++++++++++++++++++++++++++++++++---
>  1 file changed, 34 insertions(+), 3 deletions(-)
> 
> diff --git a/src/lxc/utils.c b/src/lxc/utils.c
> index 785f3e6..9fd91b7 100644
> --- a/src/lxc/utils.c
> +++ b/src/lxc/utils.c
> @@ -39,6 +39,7 @@
>  #include <sys/types.h>
>  #include <sys/wait.h>
>  #include <assert.h>
> +#include <wordexp.h>
>  
>  #ifndef HAVE_GETLINE
>  #ifdef HAVE_FGETLN
> @@ -248,11 +249,30 @@ const char *lxc_global_config_value(const char *option_name)
>  		{ "lvm_vg",          DEFAULT_VG      },
>  		{ "lvm_thin_pool",   DEFAULT_THIN_POOL },
>  		{ "zfsroot",         DEFAULT_ZFSROOT },
> -		{ "lxcpath",         LXCPATH         },
> +		{ "lxcpath",         NULL            },
>  		{ "cgroup.pattern",  DEFAULT_CGROUP_PATTERN },
>  		{ "cgroup.use",      NULL            },
>  		{ NULL, NULL },
>  	};
> +
> +	char *user_config_path;
> +	char *user_lxc_path;
> +	wordexp_t exp;
> +
> +	if (geteuid() > 0) {
> +		wordexp("~/.config/lxc/lxc.conf", &exp, 0);
> +		user_config_path = strdup(exp.we_wordv[0]);
> +		wordfree(&exp);
> +
> +		wordexp("~/.local/share/lxc/", &exp, 0);
> +		user_lxc_path = strdup(exp.we_wordv[0]);
> +		wordfree(&exp);
> +	}
> +	else {
> +		user_config_path = strdup(LXC_GLOBAL_CONF);
> +		user_lxc_path = strdup(LXCPATH);
> +	}
> +
>  	/* placed in the thread local storage pool */
>  	static __thread const char *values[sizeof(options) / sizeof(options[0])] = { 0 };
>  	const char *(*ptr)[2];
> @@ -266,17 +286,23 @@ const char *lxc_global_config_value(const char *option_name)
>  			break;
>  	}
>  	if (!(*ptr)[0]) {
> +		free(user_config_path);
> +		free(user_lxc_path);
>  		errno = EINVAL;
>  		return NULL;
>  	}
>  
>  	if (values[i]) {
> +		free(user_config_path);
> +		free(user_lxc_path);
>  		value = values[i];
> +
>  		return value;
>  	}
>  
>  	process_lock();
> -	fin = fopen_cloexec(LXC_GLOBAL_CONF, "r");
> +	fin = fopen_cloexec(user_config_path, "r");
> +	free(user_config_path);
>  	process_unlock();
>  	if (fin) {
>  		while (fgets(buf, 1024, fin)) {
> @@ -315,7 +341,12 @@ const char *lxc_global_config_value(const char *option_name)
>  		}
>  	}
>  	/* could not find value, use default */
> -	values[i] = (*ptr)[1];
> +	if (strcmp(option_name, "lxcpath") == 0)
> +		values[i] = user_lxc_path;
> +	else {
> +		free(user_config_path);

Did you mean to free user_lxc_path here?

> +		values[i] = (*ptr)[1];
> +	}
>  	/* special case: if default value is NULL,
>  	 * and there is no config, don't view that
>  	 * as an error... */

Below here is an out: path.  I don't think you're freeing
user_lxc_path on that codepath.

> -- 
> 1.8.5.2
> 
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