On Tue, 2009-09-01 at 15:34 +0100, Martin Orr wrote:
> Here's a patch that works, and does what I want.
>
> It moves most of process_one into process_one_realpath, which assumes that
> the path it is given requires no further expansion.
> Now if given a symlink, call symlink_realpath to get the real path ignoring
> the last component, and give that to process_one_realpath; tell
> process_one_realpath not to recurse so this acts on the symlink only.
> Then call process_one_realpath again with the real path of the target, to
> recurse into it.
The function naming seems the reverse of what one might expect (the
function with _realpath in the name doesn't call realpath). Also, you
can pass NULL for the resolved path argument to realpath() rather than
giving it a fixed-size buffer from the stack and let it allocate the
buffer for you, as we already do elsewhere.
Not sure it is worth warning about the broken symlink case, and that
will trigger warnings for your existing users in the
restorecon /dev/stdin case, right?
> diff --git a/policycoreutils/setfiles/setfiles.c b/policycoreutils/setfiles/setfiles.c
> index 4c47f21..c84cd6f 100644
> --- a/policycoreutils/setfiles/setfiles.c
> +++ b/policycoreutils/setfiles/setfiles.c
> @@ -545,7 +545,47 @@ int canoncon(char **contextp)
> return rc;
> }
>
> -static int process_one(char *name)
> +static int symlink_realpath(char *name, char *path)
> +{
> + char *p = NULL, *file_sep;
> + char *tmp_path = strdupa(name);
> + size_t len = 0;
> +
> + if (!tmp_path) {
> + fprintf(stderr, "strdupa on %s failed: %s\n", name,
> + strerror(errno));
> + return -1;
> + }
> + file_sep = strrchr(tmp_path, '/');
> + if (file_sep == tmp_path) {
> + file_sep++;
> + p = strcpy(path, "");
> + } else if (file_sep) {
> + *file_sep = 0;
> + file_sep++;
> + p = realpath(tmp_path, path);
> + } else {
> + file_sep = tmp_path;
> + p = realpath("./", path);
> + }
> + if (p)
> + len = strlen(p);
> + if (!p || len + strlen(file_sep) + 2 > PATH_MAX) {
> + fprintf(stderr, "symlink_realpath(%s) failed %s\n", name,
> + strerror(errno));
> + return -1;
> + }
> + p += len;
> + /* ensure trailing slash of directory name */
> + if (len == 0 || *(p - 1) != '/') {
> + *p = '/';
> + p++;
> + }
> + strcpy(p, file_sep);
> + return 0;
> +}
> +
> +static int process_one_realpath(char *name, int recurse_this_path)
> {
> int rc = 0;
> const char *namelist[2];
> @@ -553,18 +593,6 @@ static int process_one(char *name)
> FTS *fts_handle;
> FTSENT *ftsent;
>
> - if (expand_realpath) {
> - char *p;
> - p = realpath(name, NULL);
> - if (!p) {
> - fprintf(stderr, "realpath(%s) failed %s\n", name,
> - strerror(errno));
> - return -1;
> - }
> - name = p;
> - }
> -
> -
> if (!strcmp(name, "/"))
> mass_relabel = 1;
>
> @@ -604,7 +632,7 @@ static int process_one(char *name)
> fts_set(fts_handle, ftsent, FTS_SKIP);
> if (rc == ERR)
> goto err;
> - if (!recurse)
> + if (!recurse_this_path)
> break;
> } while ((ftsent = fts_read(fts_handle)) != NULL);
>
> @@ -619,8 +647,6 @@ out:
> }
> if (fts_handle)
> fts_close(fts_handle);
> - if (expand_realpath)
> - free(name);
> return rc;
>
> err:
> @@ -630,6 +656,55 @@ err:
> goto out;
> }
>
> +static int process_one(char *name)
> +{
> + int rc = 0;
> + char *p;
> + struct stat sb;
> +
> + if (!expand_realpath) {
> + return process_one_realpath(name, recurse);
> + } else {
> + rc = lstat(name, &sb);
> + if (rc < 0) {
> + fprintf(stderr, "%s: lstat(%s) failed: %s\n",
> + progname, name, strerror(errno));
> + return -1;
> + }
> +
> + if (S_ISLNK(sb.st_mode)) {
> + char path[PATH_MAX + 1];
> +
> + rc = symlink_realpath(name, path);
> + if (rc < 0)
> + return rc;
> + rc = process_one_realpath(path, 0);
> + if (rc < 0)
> + return rc;
> +
> + p = realpath(name, NULL);
> + if (!p) {
> + fprintf(stderr, "Warning: %s: Broken symlink: %s\n",
> + name, strerror(errno));
> + return 0;
> + }
> + rc = process_one_realpath(p, recurse);
> + free(p);
> + return rc;
> + } else {
> + p = realpath(name, NULL);
> + if (!p) {
> + fprintf(stderr, "realpath(%s) failed %s\n", name,
> + strerror(errno));
> + return -1;
> + }
> + rc = process_one_realpath(p, recurse);
> + free(p);
> + return rc;
> + }
> + }
> +}
> +
> #ifndef USE_AUDIT
> static void maybe_audit_mass_relabel(void)
> {
>
--
Stephen Smalley
National Security Agency
--
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