Extract an _alpm_pkg_validate_internal() method

_alpm_pkg_load_internal() was becoming a monster. Extract the top bit of
the method that dealt with checksum and signature validation into a
separate method that should be called before one loads a package to
ensure it is valid.

Signed-off-by: Dan McGee <dan@archlinux.org>

3 files changed, 68 insertions, 37 deletions

diff --git a/lib/libalpm/be_package.c b/lib/libalpm/be_package.c
index ff820b80..b6cb8c4e 100644
--- a/lib/libalpm/be_package.c
+++ b/lib/libalpm/be_package.c
@@ -273,42 +273,26 @@ static alpm_file_t *files_msort(alpm_file_t *files, size_t n)
 }
 
 /**
- * Load a package and create the corresponding alpm_pkg_t struct.
+ * Validate a package.
  * @param handle the context handle
  * @param pkgfile path to the package file
  * @param syncpkg package object to load verification data from (md5sum,
  * sha256sum, and/or base64 signature)
- * @param full whether to stop the load after metadata is read or continue
- * through the full archive
  * @param level the required level of signature verification
- * @return An information filled alpm_pkg_t struct
+ * @return 0 if package is fully valid, -1 and pm_errno otherwise
  */
-alpm_pkg_t *_alpm_pkg_load_internal(alpm_handle_t *handle, const char *pkgfile,
-		alpm_pkg_t *syncpkg, int full, alpm_siglevel_t level)
+int _alpm_pkg_validate_internal(alpm_handle_t *handle,
+		const char *pkgfile, alpm_pkg_t *syncpkg, alpm_siglevel_t level)
 {
-	int ret, has_sig, config = 0;
-	struct archive *archive;
-	struct archive_entry *entry;
-	alpm_pkg_t *newpkg = NULL;
-	struct stat st;
-	size_t files_count = 0, files_size = 0;
-	alpm_file_t *files = NULL;
+	int has_sig;
 
 	if(pkgfile == NULL || strlen(pkgfile) == 0) {
-		RET_ERR(handle, ALPM_ERR_WRONG_ARGS, NULL);
+		RET_ERR(handle, ALPM_ERR_WRONG_ARGS, -1);
 	}
 
-	/* attempt to stat the package file, ensure it exists */
-	if(stat(pkgfile, &st) == 0) {
-		newpkg = _alpm_pkg_new();
-		if(newpkg == NULL) {
-			RET_ERR(handle, ALPM_ERR_MEMORY, NULL);
-		}
-		newpkg->filename = strdup(pkgfile);
-		newpkg->size = st.st_size;
-	} else {
-		/* couldn't stat the pkgfile, return an error */
-		RET_ERR(handle, ALPM_ERR_PKG_NOT_FOUND, NULL);
+	/* attempt to access the package file, ensure it exists */
+	if(access(pkgfile, R_OK) != 0) {
+		RET_ERR(handle, ALPM_ERR_PKG_NOT_FOUND, -1);
 	}
 
 	/* can we get away with skipping checksums? */
@@ -330,8 +314,7 @@ alpm_pkg_t *_alpm_pkg_load_internal(alpm_handle_t *handle, const char *pkgfile,
 			_alpm_log(handle, ALPM_LOG_DEBUG, "md5sum: %s\n", syncpkg->md5sum);
 			_alpm_log(handle, ALPM_LOG_DEBUG, "checking md5sum for %s\n", pkgfile);
 			if(_alpm_test_checksum(pkgfile, syncpkg->md5sum, ALPM_CSUM_MD5) != 0) {
-				alpm_pkg_free(newpkg);
-				RET_ERR(handle, ALPM_ERR_PKG_INVALID_CHECKSUM, NULL);
+				RET_ERR(handle, ALPM_ERR_PKG_INVALID_CHECKSUM, -1);
 			}
 		}
 
@@ -339,8 +322,7 @@ alpm_pkg_t *_alpm_pkg_load_internal(alpm_handle_t *handle, const char *pkgfile,
 			_alpm_log(handle, ALPM_LOG_DEBUG, "sha256sum: %s\n", syncpkg->sha256sum);
 			_alpm_log(handle, ALPM_LOG_DEBUG, "checking sha256sum for %s\n", pkgfile);
 			if(_alpm_test_checksum(pkgfile, syncpkg->sha256sum, ALPM_CSUM_SHA256) != 0) {
-				alpm_pkg_free(newpkg);
-				RET_ERR(handle, ALPM_ERR_PKG_INVALID_CHECKSUM, NULL);
+				RET_ERR(handle, ALPM_ERR_PKG_INVALID_CHECKSUM, -1);
 			}
 		}
 	}
@@ -353,12 +335,49 @@ alpm_pkg_t *_alpm_pkg_load_internal(alpm_handle_t *handle, const char *pkgfile,
 					level & ALPM_SIG_PACKAGE_OPTIONAL, level & ALPM_SIG_PACKAGE_MARGINAL_OK,
 					level & ALPM_SIG_PACKAGE_UNKNOWN_OK)) {
 			handle->pm_errno = ALPM_ERR_PKG_INVALID_SIG;
-			_alpm_pkg_free(newpkg);
-			return NULL;
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * Load a package and create the corresponding alpm_pkg_t struct.
+ * @param handle the context handle
+ * @param pkgfile path to the package file
+ * @param full whether to stop the load after metadata is read or continue
+ * through the full archive
+ */
+alpm_pkg_t *_alpm_pkg_load_internal(alpm_handle_t *handle,
+		const char *pkgfile, int full)
+{
+	int ret, config = 0;
+	struct archive *archive;
+	struct archive_entry *entry;
+	alpm_pkg_t *newpkg = NULL;
+	struct stat st;
+	size_t files_count = 0, files_size = 0;
+	alpm_file_t *files = NULL;
+
+	if(pkgfile == NULL || strlen(pkgfile) == 0) {
+		RET_ERR(handle, ALPM_ERR_WRONG_ARGS, NULL);
+	}
+
+	/* attempt to stat the package file, ensure it exists */
+	if(stat(pkgfile, &st) == 0) {
+		newpkg = _alpm_pkg_new();
+		if(newpkg == NULL) {
+			RET_ERR(handle, ALPM_ERR_MEMORY, NULL);
 		}
+		newpkg->filename = strdup(pkgfile);
+		newpkg->size = st.st_size;
+	} else {
+		/* couldn't stat the pkgfile, return an error */
+		RET_ERR(handle, ALPM_ERR_PKG_NOT_FOUND, NULL);
 	}
 
-	/* next- try to create an archive object to read in the package */
+	/* try to create an archive object to read in the package */
 	if((archive = archive_read_new()) == NULL) {
 		alpm_pkg_free(newpkg);
 		RET_ERR(handle, ALPM_ERR_LIBARCHIVE, NULL);
@@ -490,7 +509,11 @@ int SYMEXPORT alpm_pkg_load(alpm_handle_t *handle, const char *filename, int ful
 	CHECK_HANDLE(handle, return -1);
 	ASSERT(pkg != NULL, RET_ERR(handle, ALPM_ERR_WRONG_ARGS, -1));
 
-	*pkg = _alpm_pkg_load_internal(handle, filename, NULL, full, level);
+	if(_alpm_pkg_validate_internal(handle, filename, NULL, level) == -1) {
+		/* pm_errno is set by pkg_validate */
+		return -1;
+	}
+	*pkg = _alpm_pkg_load_internal(handle, filename, full);
 	if(*pkg == NULL) {
 		/* pm_errno is set by pkg_load */
 		return -1;
diff --git a/lib/libalpm/package.h b/lib/libalpm/package.h
index c19625c1..fbae766c 100644
--- a/lib/libalpm/package.h
+++ b/lib/libalpm/package.h
@@ -135,8 +135,10 @@ void _alpm_pkg_free(alpm_pkg_t *pkg);
 void _alpm_pkg_free_trans(alpm_pkg_t *pkg);
 
 
-alpm_pkg_t *_alpm_pkg_load_internal(alpm_handle_t *handle, const char *pkgfile,
-		alpm_pkg_t *syncpkg, int full, alpm_siglevel_t level);
+int _alpm_pkg_validate_internal(alpm_handle_t *handle,
+		const char *pkgfile, alpm_pkg_t *syncpkg, alpm_siglevel_t level);
+alpm_pkg_t *_alpm_pkg_load_internal(alpm_handle_t *handle,
+		const char *pkgfile, int full);
 
 int _alpm_pkg_cmp(const void *p1, const void *p2);
 int _alpm_pkg_compare_versions(alpm_pkg_t *local_pkg, alpm_pkg_t *pkg);
diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index 732e786f..a5281078 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -971,14 +971,20 @@ int _alpm_sync_commit(alpm_handle_t *handle, alpm_list_t **data)
 		_alpm_log(handle, ALPM_LOG_DEBUG,
 				"replacing pkgcache entry with package file for target %s\n",
 				spkg->name);
-		alpm_pkg_t *pkgfile =_alpm_pkg_load_internal(handle, filepath, spkg, 1, level);
-		if(!pkgfile) {
+		if(_alpm_pkg_validate_internal(handle, filepath, spkg, level) == -1) {
 			prompt_to_delete(handle, filepath, handle->pm_errno);
 			errors++;
 			*data = alpm_list_add(*data, strdup(spkg->filename));
 			FREE(filepath);
 			continue;
 		}
+		alpm_pkg_t *pkgfile =_alpm_pkg_load_internal(handle, filepath, 1);
+		if(!pkgfile) {
+			errors++;
+			*data = alpm_list_add(*data, strdup(spkg->filename));
+			FREE(filepath);
+			continue;
+		}
 		FREE(filepath);
 		pkgfile->reason = spkg->reason; /* copy over install reason */
 		i->data = pkgfile;