fix failure to free memory

The applypatch function is somewhat sloppy about freeing memory (since
it was originally a standalone binary).  Fix some of that.

Change-Id: Ifd44d71ea189c0b5115493119fd57bc37533fd59

2 files changed, 45 insertions, 19 deletions

diff --git a/applypatch/applypatch.c b/applypatch/applypatch.c
index 1060913..09ca2ad 100644
--- a/applypatch/applypatch.c
+++ b/applypatch/applypatch.c
@@ -30,10 +30,16 @@
 #include "mtdutils/mtdutils.h"
 #include "edify/expr.h"
 
-int SaveFileContents(const char* filename, FileContents file);
 static int LoadPartitionContents(const char* filename, FileContents* file);
-int ParseSha1(const char* str, uint8_t* digest);
 static ssize_t FileSink(unsigned char* data, ssize_t len, void* token);
+static int GenerateTarget(FileContents* source_file,
+                          const Value* source_patch_value,
+                          FileContents* copy_file,
+                          const Value* copy_patch_value,
+                          const char* source_filename,
+                          const char* target_filename,
+                          const uint8_t target_sha1[SHA_DIGEST_SIZE],
+                          size_t target_size);
 
 static int mtd_partitions_scanned = 0;
 
@@ -113,11 +119,6 @@ static int compare_size_indices(const void* a, const void* b) {
     }
 }
 
-void FreeFileContents(FileContents* file) {
-    if (file) free(file->data);
-    free(file);
-}
-
 // Load the contents of an MTD or EMMC partition into the provided
 // FileContents.  filename should be a string of the form
 // "MTD:<partition_name>:<size_1>:<sha1_1>:<size_2>:<sha1_2>:..."  (or
@@ -322,7 +323,7 @@ static int LoadPartitionContents(const char* filename, FileContents* file) {
 
 // Save the contents of the given FileContents object under the given
 // filename.  Return 0 on success.
-int SaveFileContents(const char* filename, FileContents file) {
+int SaveFileContents(const char* filename, const FileContents* file) {
     int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC);
     if (fd < 0) {
         printf("failed to open \"%s\" for write: %s\n",
@@ -330,10 +331,10 @@ int SaveFileContents(const char* filename, FileContents file) {
         return -1;
     }
 
-    ssize_t bytes_written = FileSink(file.data, file.size, &fd);
-    if (bytes_written != file.size) {
+    ssize_t bytes_written = FileSink(file->data, file->size, &fd);
+    if (bytes_written != file->size) {
         printf("short write of \"%s\" (%ld bytes of %ld) (%s)\n",
-               filename, (long)bytes_written, (long)file.size,
+               filename, (long)bytes_written, (long)file->size,
                strerror(errno));
         close(fd);
         return -1;
@@ -341,11 +342,11 @@ int SaveFileContents(const char* filename, FileContents file) {
     fsync(fd);
     close(fd);
 
-    if (chmod(filename, file.st.st_mode) != 0) {
+    if (chmod(filename, file->st.st_mode) != 0) {
         printf("chmod of \"%s\" failed: %s\n", filename, strerror(errno));
         return -1;
     }
-    if (chown(filename, file.st.st_uid, file.st.st_gid) != 0) {
+    if (chown(filename, file->st.st_uid, file->st.st_gid) != 0) {
         printf("chown of \"%s\" failed: %s\n", filename, strerror(errno));
         return -1;
     }
@@ -503,6 +504,7 @@ int applypatch_check(const char* filename,
                "sha1 sums; checking cache\n", filename);
 
         free(file.data);
+        file.data = NULL;
 
         // If the source file is missing or corrupted, it might be because
         // we were killed in the middle of patching it.  A copy of it
@@ -631,9 +633,10 @@ int applypatch(const char* source_filename,
 
     FileContents copy_file;
     FileContents source_file;
+    copy_file.data = NULL;
+    source_file.data = NULL;
     const Value* source_patch_value = NULL;
     const Value* copy_patch_value = NULL;
-    int made_copy = 0;
 
     // We try to load the target file into the source_file object.
     if (LoadFileContents(target_filename, &source_file,
@@ -643,6 +646,7 @@ int applypatch(const char* source_filename,
             // has the desired hash, nothing for us to do.
             printf("\"%s\" is already target; no patch needed\n",
                    target_filename);
+            free(source_file.data);
             return 0;
         }
     }
@@ -653,6 +657,7 @@ int applypatch(const char* source_filename,
         // Need to load the source file:  either we failed to load the
         // target file, or we did but it's different from the source file.
         free(source_file.data);
+        source_file.data = NULL;
         LoadFileContents(source_filename, &source_file,
                          RETOUCH_DO_MASK);
     }
@@ -667,6 +672,7 @@ int applypatch(const char* source_filename,
 
     if (source_patch_value == NULL) {
         free(source_file.data);
+        source_file.data = NULL;
         printf("source file is bad; trying copy\n");
 
         if (LoadFileContents(CACHE_TEMP_SOURCE, &copy_file,
@@ -685,16 +691,36 @@ int applypatch(const char* source_filename,
         if (copy_patch_value == NULL) {
             // fail.
             printf("copy file doesn't match source SHA-1s either\n");
+            free(copy_file.data);
             return 1;
         }
     }
 
+    int result = GenerateTarget(&source_file, source_patch_value,
+                                &copy_file, copy_patch_value,
+                                source_filename, target_filename,
+                                target_sha1, target_size);
+    free(source_file.data);
+    free(copy_file.data);
+
+    return result;
+}
+
+static int GenerateTarget(FileContents* source_file,
+                          const Value* source_patch_value,
+                          FileContents* copy_file,
+                          const Value* copy_patch_value,
+                          const char* source_filename,
+                          const char* target_filename,
+                          const uint8_t target_sha1[SHA_DIGEST_SIZE],
+                          size_t target_size) {
     int retry = 1;
     SHA_CTX ctx;
     int output;
     MemorySinkInfo msi;
     FileContents* source_to_use;
     char* outname;
+    int made_copy = 0;
 
     // assume that target_filename (eg "/system/app/Foo.apk") is located
     // on the same filesystem as its top-level directory ("/system").
@@ -723,7 +749,7 @@ int applypatch(const char* source_filename,
 
             // We still write the original source to cache, in case
             // the partition write is interrupted.
-            if (MakeFreeSpaceOnCache(source_file.size) < 0) {
+            if (MakeFreeSpaceOnCache(source_file->size) < 0) {
                 printf("not enough free space on /cache\n");
                 return 1;
             }
@@ -763,7 +789,7 @@ int applypatch(const char* source_filename,
                     return 1;
                 }
 
-                if (MakeFreeSpaceOnCache(source_file.size) < 0) {
+                if (MakeFreeSpaceOnCache(source_file->size) < 0) {
                     printf("not enough free space on /cache\n");
                     return 1;
                 }
@@ -782,10 +808,10 @@ int applypatch(const char* source_filename,
 
         const Value* patch;
         if (source_patch_value != NULL) {
-            source_to_use = &source_file;
+            source_to_use = source_file;
             patch = source_patch_value;
         } else {
-            source_to_use = &copy_file;
+            source_to_use = copy_file;
             patch = copy_patch_value;
         }
 
diff --git a/applypatch/applypatch.h b/applypatch/applypatch.h
index a78c89b..e8ac3cc 100644
--- a/applypatch/applypatch.h
+++ b/applypatch/applypatch.h
@@ -62,7 +62,7 @@ int applypatch_check(const char* filename,
 
 int LoadFileContents(const char* filename, FileContents* file,
                      int retouch_flag);
-int SaveFileContents(const char* filename, FileContents file);
+int SaveFileContents(const char* filename, const FileContents* file);
 void FreeFileContents(FileContents* file);
 int FindMatchingPatch(uint8_t* sha1, char** const patch_sha1_str,
                       int num_patches);