[PATCH opkg 2/5] libopkg: factor out checksum and size verification

[Baptiste Jonglez]

From: Baptiste Jonglez <git at bitsofnetworks.org>

This is a sizeable chunk of code that be can pretty well isolated in its
own function.

This refactoring will be necessary for an upcoming feature in which
opkg_download_pkg() will need to verify the checksum of packages in the
cache.  This is the reason why the new function is located in
`opkg_download.c`.

Signed-off-by: Baptiste Jonglez <git at bitsofnetworks.org>
---
 libopkg/opkg_download.c | 78 +++++++++++++++++++++++++++++++++++++++++
 libopkg/opkg_download.h |  1 +
 libopkg/opkg_install.c  | 71 ++-----------------------------------
 3 files changed, 81 insertions(+), 69 deletions(-)

diff --git a/libopkg/opkg_download.c b/libopkg/opkg_download.c
index 97df37f..f7c2f88 100644
--- a/libopkg/opkg_download.c
+++ b/libopkg/opkg_download.c
@@ -35,6 +35,84 @@ static int str_starts_with(const char *str, const char *prefix)
 	return (strncmp(str, prefix, strlen(prefix)) == 0);
 }
 
+int opkg_verify_integrity(pkg_t *pkg, const char *filename)
+{
+	int err = 0;
+	char *file_md5, *pkg_md5;
+	char *file_sha256, *pkg_sha256;
+	struct stat pkg_stat;
+	long long int pkg_expected_size;
+
+	/* Check file size */
+	err = lstat(filename, &pkg_stat);
+
+	if (err) {
+		opkg_msg(ERROR, "Failed to stat %s: %s\n",
+		         filename, strerror(errno));
+		return err;
+	}
+
+	pkg_expected_size = pkg_get_int(pkg, PKG_SIZE);
+
+	if (pkg_expected_size > 0 && pkg_stat.st_size != pkg_expected_size) {
+		if (!conf->force_checksum) {
+			opkg_msg(ERROR,
+			         "Package size mismatch: %s is %lld bytes, expecting %lld bytes\n",
+			         pkg->name, (long long int)pkg_stat.st_size, pkg_expected_size);
+			return -1;
+		} else {
+			opkg_msg(NOTICE,
+			         "Ignored %s size mismatch.\n",
+			         pkg->name);
+		}
+	}
+
+	/* Check for md5 values */
+	pkg_md5 = pkg_get_md5(pkg);
+	if (pkg_md5) {
+		file_md5 = file_md5sum_alloc(filename);
+		if (file_md5 && strcmp(file_md5, pkg_md5)) {
+			if (!conf->force_checksum) {
+				opkg_msg(ERROR, "Package %s md5sum mismatch. "
+					 "Either the opkg or the package index are corrupt. "
+					 "Try 'opkg update'.\n", pkg->name);
+				free(file_md5);
+				return -1;
+			} else {
+				opkg_msg(NOTICE,
+					 "Ignored %s md5sum mismatch.\n",
+					 pkg->name);
+			}
+		}
+		if (file_md5)
+			free(file_md5);
+	}
+
+	/* Check for sha256 value */
+	pkg_sha256 = pkg_get_sha256(pkg);
+	if (pkg_sha256) {
+		file_sha256 = file_sha256sum_alloc(filename);
+		if (file_sha256 && strcmp(file_sha256, pkg_sha256)) {
+			if (!conf->force_checksum) {
+				opkg_msg(ERROR,
+					 "Package %s sha256sum mismatch. "
+					 "Either the opkg or the package index are corrupt. "
+					 "Try 'opkg update'.\n", pkg->name);
+				free(file_sha256);
+				return -1;
+			} else {
+				opkg_msg(NOTICE,
+					 "Ignored %s sha256sum mismatch.\n",
+					 pkg->name);
+			}
+		}
+		if (file_sha256)
+			free(file_sha256);
+	}
+
+	return err;
+}
+
 int
 opkg_download(const char *src, const char *dest_file_name,
               const short hide_error)
diff --git a/libopkg/opkg_download.h b/libopkg/opkg_download.h
index fd260bc..863bcf2 100644
--- a/libopkg/opkg_download.h
+++ b/libopkg/opkg_download.h
@@ -20,6 +20,7 @@
 
 #include "pkg.h"
 
+int opkg_verify_integrity(pkg_t *pkg, const char *filename);
 int opkg_download(const char *src, const char *dest_file_name,
                   const short hide_error);
 int opkg_download_pkg(pkg_t * pkg, const char *dir);
diff --git a/libopkg/opkg_install.c b/libopkg/opkg_install.c
index 27c9484..e8eccf8 100644
--- a/libopkg/opkg_install.c
+++ b/libopkg/opkg_install.c
@@ -1250,12 +1250,8 @@ int opkg_install_pkg(pkg_t * pkg, int from_upgrade)
 	pkg_vec_t *replacees;
 	abstract_pkg_t *ab_pkg = NULL;
 	int old_state_flag;
-	char *file_md5, *pkg_md5;
-	char *file_sha256, *pkg_sha256;
 	sigset_t newset, oldset;
 	const char *local_filename;
-	long long int pkg_expected_size;
-	struct stat pkg_stat;
 	time_t now;
 
 	if (from_upgrade)
@@ -1367,72 +1363,9 @@ int opkg_install_pkg(pkg_t * pkg, int from_upgrade)
 	}
 #endif
 
-	/* Check file size */
-	err = lstat(local_filename, &pkg_stat);
-
-	if (err) {
-		opkg_msg(ERROR, "Failed to stat %s: %s\n",
-		         local_filename, strerror(errno));
+	err = opkg_verify_integrity(pkg, local_filename);
+	if (err)
 		return -1;
-	}
-
-	pkg_expected_size = pkg_get_int(pkg, PKG_SIZE);
-
-	if (pkg_expected_size > 0 && pkg_stat.st_size != pkg_expected_size) {
-		if (!conf->force_checksum) {
-			opkg_msg(ERROR,
-			         "Package size mismatch: %s is %lld bytes, expecting %lld bytes\n",
-			         pkg->name, (long long int)pkg_stat.st_size, pkg_expected_size);
-			return -1;
-		} else {
-			opkg_msg(NOTICE,
-			         "Ignored %s size mismatch.\n",
-			         pkg->name);
-		}
-	}
-
-	/* Check for md5 values */
-	pkg_md5 = pkg_get_md5(pkg);
-	if (pkg_md5) {
-		file_md5 = file_md5sum_alloc(local_filename);
-		if (file_md5 && strcmp(file_md5, pkg_md5)) {
-			if (!conf->force_checksum) {
-				opkg_msg(ERROR, "Package %s md5sum mismatch. "
-					 "Either the opkg or the package index are corrupt. "
-					 "Try 'opkg update'.\n", pkg->name);
-				free(file_md5);
-				return -1;
-			} else {
-				opkg_msg(NOTICE,
-					 "Ignored %s md5sum mismatch.\n",
-					 pkg->name);
-			}
-		}
-		if (file_md5)
-			free(file_md5);
-	}
-
-	/* Check for sha256 value */
-	pkg_sha256 = pkg_get_sha256(pkg);
-	if (pkg_sha256) {
-		file_sha256 = file_sha256sum_alloc(local_filename);
-		if (file_sha256 && strcmp(file_sha256, pkg_sha256)) {
-			if (!conf->force_checksum) {
-				opkg_msg(ERROR,
-					 "Package %s sha256sum mismatch. "
-					 "Either the opkg or the package index are corrupt. "
-					 "Try 'opkg update'.\n", pkg->name);
-				free(file_sha256);
-				return -1;
-			} else {
-				opkg_msg(NOTICE,
-					 "Ignored %s sha256sum mismatch.\n",
-					 pkg->name);
-			}
-		}
-		if (file_sha256)
-			free(file_sha256);
-	}
 
 	if (conf->download_only) {
 		if (conf->nodeps == 0) {
-- 
2.27.0