On Mon, 2017-09-11 at 11:04 -0700, Daniel Cashman wrote: > From: Dan Cashman <[email protected]> > > The file_contexts labeling backend, specified in label_file.c, > currently assumes > that only one path will be specified as an option to > selabel_open(). The split > of platform and non-platform policy on device, however, will > necessitate the > loading of two disparate policy files. Rather than combining the > files and then > calling the existing API on a newly-formed file, just add the ability > to specify > multiple files to use. Order of opt specification to selabel_open > matters. > > This corresponds to AOSP commit > 50400d38203e4db08314168e60c281cc61a717a8, which > lead to a fork with upstream, which we'd like to correct.
We need to update the other label backends as well, at least sufficiently to still build, even if they only support a single path. > > Signed-off-by: Dan Cashman <[email protected]> > --- > libselinux/src/label.c | 21 +++++--- > libselinux/src/label_file.c | 104 +++++++++++++++++++++++++++++- > ---------- > libselinux/src/label_internal.h | 5 +- > 3 files changed, 94 insertions(+), 36 deletions(-) > > diff --git a/libselinux/src/label.c b/libselinux/src/label.c > index 48f4d2d6..0dfa054c 100644 > --- a/libselinux/src/label.c > +++ b/libselinux/src/label.c > @@ -143,7 +143,11 @@ static int selabel_fini(struct selabel_handle > *rec, > struct selabel_lookup_rec *lr, > int translating) > { > - if (compat_validate(rec, lr, rec->spec_file, 0)) > + char *path = NULL; > + > + if (rec->spec_files) > + path = rec->spec_files[0]; > + if (compat_validate(rec, lr, path, 0)) > return -1; > > if (translating && !lr->ctx_trans && > @@ -226,11 +230,9 @@ struct selabel_handle *selabel_open(unsigned int > backend, > rec->digest = selabel_is_digest_set(opts, nopts, rec- > >digest); > > if ((*initfuncs[backend])(rec, opts, nopts)) { > - free(rec->spec_file); > - free(rec); > + selabel_close(rec); > rec = NULL; > } > - > out: > return rec; > } > @@ -337,10 +339,17 @@ int selabel_digest(struct selabel_handle *rec, > > void selabel_close(struct selabel_handle *rec) > { > + size_t i; > + > + if (rec->spec_files) { > + for (i = 0; i < rec->spec_files_len; i++) > + free(rec->spec_files[i]); > + free(rec->spec_files); > + } > if (rec->digest) > selabel_digest_fini(rec->digest); > - rec->func_close(rec); > - free(rec->spec_file); > + if (rec->func_close) > + rec->func_close(rec); > free(rec); > } > > diff --git a/libselinux/src/label_file.c > b/libselinux/src/label_file.c > index 560d8c3d..b3b36bc2 100644 > --- a/libselinux/src/label_file.c > +++ b/libselinux/src/label_file.c > @@ -709,28 +709,61 @@ static int init(struct selabel_handle *rec, > const struct selinux_opt *opts, > unsigned n) > { > struct saved_data *data = (struct saved_data *)rec->data; > - const char *path = NULL; > + size_t num_paths = 0; > + char **path = NULL; > const char *prefix = NULL; > - int status = -1, baseonly = 0; > + int status = -1; > + size_t i; > + bool baseonly = false; > + bool path_provided; > > /* Process arguments */ > - while (n--) > - switch(opts[n].type) { > + i = n; > + while (i--) > + switch(opts[i].type) { > case SELABEL_OPT_PATH: > - path = opts[n].value; > + num_paths++; > break; > case SELABEL_OPT_SUBSET: > - prefix = opts[n].value; > + prefix = opts[i].value; > break; > case SELABEL_OPT_BASEONLY: > - baseonly = !!opts[n].value; > + baseonly = !!opts[i].value; > break; > } > > + if (!num_paths) { > + num_paths = 1; > + path_provided = false; > + } else { > + path_provided = true; > + } > + > + path = calloc(num_paths, sizeof(*path)); > + if (path == NULL) { > + goto finish; > + } > + rec->spec_files = path; > + rec->spec_files_len = num_paths; > + > + if (path_provided) { > + for (i = 0; i < n; i++) { > + switch(opts[i].type) { > + case SELABEL_OPT_PATH: > + *path = strdup(opts[i].value); > + if (*path == NULL) > + goto finish; > + path++; > + break; > + default: > + break; > + } > + } > + } > #if !defined(BUILD_HOST) && !defined(ANDROID) > char subs_file[PATH_MAX + 1]; > /* Process local and distribution substitution files */ > - if (!path) { > + if (!path_provided) { > status = selabel_subs_init( > selinux_file_context_subs_dist_path(), > rec->digest, &data->dist_subs); > @@ -740,43 +773,52 @@ static int init(struct selabel_handle *rec, > const struct selinux_opt *opts, > rec->digest, &data->subs); > if (status) > goto finish; > - path = selinux_file_context_path(); > + rec->spec_files[0] = > strdup(selinux_file_context_path()); > + if (rec->spec_files[0] == NULL) > + goto finish; > } else { > - snprintf(subs_file, sizeof(subs_file), > "%s.subs_dist", path); > - status = selabel_subs_init(subs_file, rec->digest, > + for (i = 0; i < num_paths; i++) { > + snprintf(subs_file, sizeof(subs_file), > "%s.subs_dist", rec->spec_files[i]); > + status = selabel_subs_init(subs_file, rec- > >digest, > &data->dist_subs); > - if (status) > - goto finish; > - snprintf(subs_file, sizeof(subs_file), "%s.subs", > path); > - status = selabel_subs_init(subs_file, rec->digest, > + if (status) > + goto finish; > + snprintf(subs_file, sizeof(subs_file), > "%s.subs", rec->spec_files[i]); > + status = selabel_subs_init(subs_file, rec- > >digest, > &data->subs); > - if (status) > - goto finish; > + if (status) > + goto finish; > + } > + } > +#else > + if (!path_provided) { > + selinux_log(SELINUX_ERROR, "No path given to file > labeling backend\n"); > + goto finish; > } > - > #endif > - rec->spec_file = strdup(path); > > /* > - * The do detailed validation of the input and fill the spec > array > + * Do detailed validation of the input and fill the spec > array > */ > - status = process_file(path, NULL, rec, prefix, rec->digest); > - if (status) > - goto finish; > - > - if (rec->validating) { > - status = nodups_specs(data, path); > + for (i = 0; i < num_paths; i++) { > + status = process_file(rec->spec_files[i], NULL, rec, > prefix, rec->digest); > if (status) > goto finish; > + > + if (rec->validating) { > + status = nodups_specs(data, rec- > >spec_files[i]); > + if (status) > + goto finish; > + } > } > > if (!baseonly) { > - status = process_file(path, "homedirs", rec, prefix, > + status = process_file(rec->spec_files[0], > "homedirs", rec, prefix, > rec- > >digest); > if (status && errno != ENOENT) > goto finish; > > - status = process_file(path, "local", rec, prefix, > + status = process_file(rec->spec_files[0], "local", > rec, prefix, > rec- > >digest); > if (status && errno != ENOENT) > goto finish; > @@ -804,6 +846,12 @@ static void closef(struct selabel_handle *rec) > struct stem *stem; > unsigned int i; > > + if (!data) > + return; > + > + /* make sure successive ->func_close() calls are harmless */ > + rec->data = NULL; > + > selabel_subs_fini(data->subs); > selabel_subs_fini(data->dist_subs); > > diff --git a/libselinux/src/label_internal.h > b/libselinux/src/label_internal.h > index c55efb75..43b63513 100644 > --- a/libselinux/src/label_internal.h > +++ b/libselinux/src/label_internal.h > @@ -98,10 +98,11 @@ struct selabel_handle { > void *data; > > /* > - * The main spec file used. Note for file contexts the local > and/or > + * The main spec file(s) used. Note for file contexts the > local and/or > * homedirs could also have been used to resolve a context. > */ > - char *spec_file; > + size_t spec_files_len; > + char **spec_files; > > /* ptr to SHA1 hash information if SELABEL_OPT_DIGEST set */ > struct selabel_digest *digest;
