EMMC support in applypatch

Let applypatch read and write EMMC partitions as well as MTD ones.
This enables incremental updates that include boot image changes, as
well as OTA of new recovery partitions.

Change-Id: I3766b9e77c639769ddf693b675da51d57f6e6b1d

1 files changed, 175 insertions, 102 deletions

diff --git a/applypatch/applypatch.c b/applypatch/applypatch.c
index 99d3661..d182821 100644
--- a/applypatch/applypatch.c
+++ b/applypatch/applypatch.c
@@ -30,10 +30,10 @@
 #include "mtdutils/mtdutils.h"
 #include "edify/expr.h"
 
-int SaveFileContents(const char* filename, FileContents file);
-int LoadMTDContents(const char* filename, FileContents* file);
+static int SaveFileContents(const char* filename, FileContents file);
+static int LoadPartitionContents(const char* filename, FileContents* file);
 int ParseSha1(const char* str, uint8_t* digest);
-ssize_t FileSink(unsigned char* data, ssize_t len, void* token);
+static ssize_t FileSink(unsigned char* data, ssize_t len, void* token);
 
 static int mtd_partitions_scanned = 0;
 
@@ -42,10 +42,11 @@ static int mtd_partitions_scanned = 0;
 int LoadFileContents(const char* filename, FileContents* file) {
     file->data = NULL;
 
-    // A special 'filename' beginning with "MTD:" means to load the
-    // contents of an MTD partition.
-    if (strncmp(filename, "MTD:", 4) == 0) {
-        return LoadMTDContents(filename, file);
+    // A special 'filename' beginning with "MTD:" or "EMMC:" means to
+    // load the contents of a partition.
+    if (strncmp(filename, "MTD:", 4) == 0 ||
+        strncmp(filename, "EMMC:", 5) == 0) {
+        return LoadPartitionContents(filename, file);
     }
 
     if (stat(filename, &file->st) != 0) {
@@ -98,26 +99,35 @@ void FreeFileContents(FileContents* file) {
     free(file);
 }
 
-// Load the contents of an MTD partition into the provided
+// 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>:...".
-// The smallest size_n bytes for which that prefix of the mtd contents
-// has the corresponding sha1 hash will be loaded.  It is acceptable
-// for a size value to be repeated with different sha1s.  Will return
-// 0 on success.
+// "MTD:<partition_name>:<size_1>:<sha1_1>:<size_2>:<sha1_2>:..."  (or
+// "EMMC:<partition_device>:...").  The smallest size_n bytes for
+// which that prefix of the partition contents has the corresponding
+// sha1 hash will be loaded.  It is acceptable for a size value to be
+// repeated with different sha1s.  Will return 0 on success.
 //
 // This complexity is needed because if an OTA installation is
 // interrupted, the partition might contain either the source or the
 // target data, which might be of different lengths.  We need to know
-// the length in order to read from MTD (there is no "end-of-file"
-// marker), so the caller must specify the possible lengths and the
-// hash of the data, and we'll do the load expecting to find one of
-// those hashes.
-int LoadMTDContents(const char* filename, FileContents* file) {
+// the length in order to read from a partition (there is no
+// "end-of-file" marker), so the caller must specify the possible
+// lengths and the hash of the data, and we'll do the load expecting
+// to find one of those hashes.
+enum PartitionType { MTD, EMMC };
+
+static int LoadPartitionContents(const char* filename, FileContents* file) {
     char* copy = strdup(filename);
     const char* magic = strtok(copy, ":");
-    if (strcmp(magic, "MTD") != 0) {
-        printf("LoadMTDContents called with bad filename (%s)\n",
+
+    enum PartitionType type;
+
+    if (strcmp(magic, "MTD") == 0) {
+        type = MTD;
+    } else if (strcmp(magic, "EMMC") == 0) {
+        type = EMMC;
+    } else {
+        printf("LoadPartitionContents called with bad filename (%s)\n",
                filename);
         return -1;
     }
@@ -131,7 +141,7 @@ int LoadMTDContents(const char* filename, FileContents* file) {
         }
     }
     if (colons < 3 || colons%2 == 0) {
-        printf("LoadMTDContents called with bad filename (%s)\n",
+        printf("LoadPartitionContents called with bad filename (%s)\n",
                filename);
     }
 
@@ -144,7 +154,7 @@ int LoadMTDContents(const char* filename, FileContents* file) {
         const char* size_str = strtok(NULL, ":");
         size[i] = strtol(size_str, NULL, 10);
         if (size[i] == 0) {
-            printf("LoadMTDContents called with bad size (%s)\n", filename);
+            printf("LoadPartitionContents called with bad size (%s)\n", filename);
             return -1;
         }
         sha1sum[i] = strtok(NULL, ":");
@@ -156,23 +166,38 @@ int LoadMTDContents(const char* filename, FileContents* file) {
     size_array = size;
     qsort(index, pairs, sizeof(int), compare_size_indices);
 
-    if (!mtd_partitions_scanned) {
-        mtd_scan_partitions();
-        mtd_partitions_scanned = 1;
-    }
+    MtdReadContext* ctx = NULL;
+    FILE* dev = NULL;
 
-    const MtdPartition* mtd = mtd_find_partition_by_name(partition);
-    if (mtd == NULL) {
-        printf("mtd partition \"%s\" not found (loading %s)\n",
-               partition, filename);
-        return -1;
-    }
+    switch (type) {
+        case MTD:
+            if (!mtd_partitions_scanned) {
+                mtd_scan_partitions();
+                mtd_partitions_scanned = 1;
+            }
 
-    MtdReadContext* ctx = mtd_read_partition(mtd);
-    if (ctx == NULL) {
-        printf("failed to initialize read of mtd partition \"%s\"\n",
-               partition);
-        return -1;
+            const MtdPartition* mtd = mtd_find_partition_by_name(partition);
+            if (mtd == NULL) {
+                printf("mtd partition \"%s\" not found (loading %s)\n",
+                       partition, filename);
+                return -1;
+            }
+
+            ctx = mtd_read_partition(mtd);
+            if (ctx == NULL) {
+                printf("failed to initialize read of mtd partition \"%s\"\n",
+                       partition);
+                return -1;
+            }
+            break;
+
+        case EMMC:
+            dev = fopen(partition, "rb");
+            if (dev == NULL) {
+                printf("failed to open emmc partition \"%s\": %s\n",
+                       partition, strerror(errno));
+                return -1;
+            }
     }
 
     SHA_CTX sha_ctx;
@@ -191,7 +216,15 @@ int LoadMTDContents(const char* filename, FileContents* file) {
         size_t next = size[index[i]] - file->size;
         size_t read = 0;
         if (next > 0) {
-            read = mtd_read_data(ctx, p, next);
+            switch (type) {
+                case MTD:
+                    read = mtd_read_data(ctx, p, next);
+                    break;
+
+                case EMMC:
+                    read = fread(p, 1, next, dev);
+                    break;
+            }
             if (next != read) {
                 printf("short read (%d bytes of %d) for partition \"%s\"\n",
                        read, next, partition);
@@ -220,7 +253,7 @@ int LoadMTDContents(const char* filename, FileContents* file) {
         if (memcmp(sha_so_far, parsed_sha, SHA_DIGEST_SIZE) == 0) {
             // we have a match.  stop reading the partition; we'll return
             // the data we've read so far.
-            printf("mtd read matched size %d sha %s\n",
+            printf("partition read matched size %d sha %s\n",
                    size[index[i]], sha1sum[index[i]]);
             break;
         }
@@ -228,12 +261,21 @@ int LoadMTDContents(const char* filename, FileContents* file) {
         p += read;
     }
 
-    mtd_read_close(ctx);
+    switch (type) {
+        case MTD:
+            mtd_read_close(ctx);
+            break;
+
+        case EMMC:
+            fclose(dev);
+            break;
+    }
+
 
     if (i == pairs) {
         // Ran off the end of the list of (size,sha1) pairs without
         // finding a match.
-        printf("contents of MTD partition \"%s\" didn't match %s\n",
+        printf("contents of partition \"%s\" didn't match %s\n",
                partition, filename);
         free(file->data);
         file->data = NULL;
@@ -261,7 +303,7 @@ int LoadMTDContents(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) {
+static int SaveFileContents(const char* filename, FileContents file) {
     int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC);
     if (fd < 0) {
         printf("failed to open \"%s\" for write: %s\n",
@@ -292,61 +334,87 @@ int SaveFileContents(const char* filename, FileContents file) {
     return 0;
 }
 
-// Write a memory buffer to target_mtd partition, a string of the form
-// "MTD:<partition>[:...]".  Return 0 on success.
-int WriteToMTDPartition(unsigned char* data, size_t len,
-                        const char* target_mtd) {
-    char* partition = strchr(target_mtd, ':');
-    if (partition == NULL) {
-        printf("bad MTD target name \"%s\"\n", target_mtd);
-        return -1;
-    }
-    ++partition;
-    // Trim off anything after a colon, eg "MTD:boot:blah:blah:blah...".
-    // We want just the partition name "boot".
-    partition = strdup(partition);
-    char* end = strchr(partition, ':');
-    if (end != NULL)
-        *end = '\0';
-
-    if (!mtd_partitions_scanned) {
-        mtd_scan_partitions();
-        mtd_partitions_scanned = 1;
-    }
+// Write a memory buffer to 'target' partition, a string of the form
+// "MTD:<partition>[:...]" or "EMMC:<partition_device>:".  Return 0 on
+// success.
+int WriteToPartition(unsigned char* data, size_t len,
+                        const char* target) {
+    char* copy = strdup(target);
+    const char* magic = strtok(copy, ":");
 
-    const MtdPartition* mtd = mtd_find_partition_by_name(partition);
-    if (mtd == NULL) {
-        printf("mtd partition \"%s\" not found for writing\n", partition);
+    enum PartitionType type;
+    if (strcmp(magic, "MTD") == 0) {
+        type = MTD;
+    } else if (strcmp(magic, "EMMC") == 0) {
+        type = EMMC;
+    } else {
+        printf("WriteToPartition called with bad target (%s)\n", target);
         return -1;
     }
+    const char* partition = strtok(NULL, ":");
 
-    MtdWriteContext* ctx = mtd_write_partition(mtd);
-    if (ctx == NULL) {
-        printf("failed to init mtd partition \"%s\" for writing\n",
-               partition);
+    if (partition == NULL) {
+        printf("bad partition target name \"%s\"\n", target);
         return -1;
     }
 
-    size_t written = mtd_write_data(ctx, (char*)data, len);
-    if (written != len) {
-        printf("only wrote %d of %d bytes to MTD %s\n",
-               written, len, partition);
-        mtd_write_close(ctx);
-        return -1;
-    }
+    switch (type) {
+        case MTD:
+            if (!mtd_partitions_scanned) {
+                mtd_scan_partitions();
+                mtd_partitions_scanned = 1;
+            }
 
-    if (mtd_erase_blocks(ctx, -1) < 0) {
-        printf("error finishing mtd write of %s\n", partition);
-        mtd_write_close(ctx);
-        return -1;
-    }
+            const MtdPartition* mtd = mtd_find_partition_by_name(partition);
+            if (mtd == NULL) {
+                printf("mtd partition \"%s\" not found for writing\n",
+                       partition);
+                return -1;
+            }
 
-    if (mtd_write_close(ctx)) {
-        printf("error closing mtd write of %s\n", partition);
-        return -1;
+            MtdWriteContext* ctx = mtd_write_partition(mtd);
+            if (ctx == NULL) {
+                printf("failed to init mtd partition \"%s\" for writing\n",
+                       partition);
+                return -1;
+            }
+
+            size_t written = mtd_write_data(ctx, (char*)data, len);
+            if (written != len) {
+                printf("only wrote %d of %d bytes to MTD %s\n",
+                       written, len, partition);
+                mtd_write_close(ctx);
+                return -1;
+            }
+
+            if (mtd_erase_blocks(ctx, -1) < 0) {
+                printf("error finishing mtd write of %s\n", partition);
+                mtd_write_close(ctx);
+                return -1;
+            }
+
+            if (mtd_write_close(ctx)) {
+                printf("error closing mtd write of %s\n", partition);
+                return -1;
+            }
+            break;
+
+        case EMMC:
+            ;
+            FILE* f = fopen(partition, "wb");
+            if (fwrite(data, 1, len, f) != len) {
+                printf("short write writing to %s (%s)\n",
+                       partition, strerror(errno));
+                return -1;
+            }
+            if (fclose(f) != 0) {
+                printf("error closing %s (%s)\n", partition, strerror(errno));
+                return -1;
+            }
+            break;
     }
 
-    free(partition);
+    free(copy);
     return 0;
 }
 
@@ -406,7 +474,7 @@ int applypatch_check(const char* filename,
     file.data = NULL;
 
     // It's okay to specify no sha1s; the check will pass if the
-    // LoadFileContents is successful.  (Useful for reading MTD
+    // LoadFileContents is successful.  (Useful for reading
     // partitions, where the filename encodes the sha1s; no need to
     // check them twice.)
     if (LoadFileContents(filename, &file) != 0 ||
@@ -518,8 +586,8 @@ int CacheSizeCheck(size_t bytes) {
 // - otherwise, or if any error is encountered, exits with non-zero
 //   status.
 //
-// <source_filename> may refer to an MTD partition to read the source
-// data.  See the comments for the LoadMTDContents() function above
+// <source_filename> may refer to a partition to read the source data.
+// See the comments for the LoadPartition Contents() function above
 // for the format of such a filename.
 
 int applypatch(const char* source_filename,
@@ -623,14 +691,16 @@ int applypatch(const char* source_filename,
         // Is there enough room in the target filesystem to hold the patched
         // file?
 
-        if (strncmp(target_filename, "MTD:", 4) == 0) {
-            // If the target is an MTD partition, we're actually going to
-            // write the output to /tmp and then copy it to the partition.
-            // statfs() always returns 0 blocks free for /tmp, so instead
-            // we'll just assume that /tmp has enough space to hold the file.
+        if (strncmp(target_filename, "MTD:", 4) == 0 ||
+            strncmp(target_filename, "EMMC:", 5) == 0) {
+            // If the target is a partition, we're actually going to
+            // write the output to /tmp and then copy it to the
+            // partition.  statfs() always returns 0 blocks free for
+            // /tmp, so instead we'll just assume that /tmp has enough
+            // space to hold the file.
 
-            // We still write the original source to cache, in case the MTD
-            // write is interrupted.
+            // We still write the original source to cache, in case
+            // the partition write is interrupted.
             if (MakeFreeSpaceOnCache(source_file.size) < 0) {
                 printf("not enough free space on /cache\n");
                 return 1;
@@ -660,11 +730,13 @@ int applypatch(const char* source_filename,
                 // copy the source file to cache, then delete it from the original
                 // location.
 
-                if (strncmp(source_filename, "MTD:", 4) == 0) {
+                if (strncmp(source_filename, "MTD:", 4) == 0 ||
+                    strncmp(source_filename, "EMMC:", 5) == 0) {
                     // It's impossible to free space on the target filesystem by
-                    // deleting the source if the source is an MTD partition.  If
+                    // deleting the source if the source is a partition.  If
                     // we're ever in a state where we need to do this, fail.
-                    printf("not enough free space for target but source is MTD\n");
+                    printf("not enough free space for target but source "
+                           "is partition\n");
                     return 1;
                 }
 
@@ -703,7 +775,8 @@ int applypatch(const char* source_filename,
         void* token = NULL;
         output = -1;
         outname = NULL;
-        if (strncmp(target_filename, "MTD:", 4) == 0) {
+        if (strncmp(target_filename, "MTD:", 4) == 0 ||
+            strncmp(target_filename, "EMMC:", 5) == 0) {
             // We store the decoded output in memory.
             msi.buffer = malloc(target_size);
             if (msi.buffer == NULL) {
@@ -779,8 +852,8 @@ int applypatch(const char* source_filename,
     }
 
     if (output < 0) {
-        // Copy the temp file to the MTD partition.
-        if (WriteToMTDPartition(msi.buffer, msi.pos, target_filename) != 0) {
+        // Copy the temp file to the partition.
+        if (WriteToPartition(msi.buffer, msi.pos, target_filename) != 0) {
             printf("write of patched data to %s failed\n", target_filename);
             return 1;
         }