idevicebackup4: fix DLMessageDownloadFiles handling

Large files were not sent correctly to the device, they must be sent in
chunks, otherwise the device gets stuck and reboots before the restore
process is complete.

1 files changed, 52 insertions, 40 deletions

diff --git a/tools/idevicebackup4.c b/tools/idevicebackup4.c
index ef3fdd0..55b7802 100644
--- a/tools/idevicebackup4.c
+++ b/tools/idevicebackup4.c
@@ -42,8 +42,9 @@
 #define LOCK_ATTEMPTS 50
 #define LOCK_WAIT 200000
 
-#define CODE_NULL 0x00
-#define CODE_ERROR_MSG 0x0b
+#define CODE_SUCCESS 0x00
+#define CODE_ERROR_LOCAL 0x06
+#define CODE_ERROR_REMOTE 0x0b
 #define CODE_FILE_DATA 0x0c
 
 static mobilebackup2_client_t mobilebackup2 = NULL;
@@ -823,35 +824,38 @@ static int handle_send_file(const char *backup_dir, const char *path, plist_t *e
 {
         uint32_t nlen = 0;
         uint32_t pathlen = strlen(path);
-        int bytes = 0;
+        uint32_t bytes = 0;
         gchar *localfile = g_build_path(G_DIR_SEPARATOR_S, backup_dir, path, NULL);
-        char buf[16384];
+        char buf[32768];
         struct stat fst;
 
         FILE *f = NULL;
         uint32_t slen = 0;
         int errcode = -1;
-        int e = -1;
+        int result = -1;
+        uint32_t length;
+        off_t total;
+        off_t sent;
 
         mobilebackup2_error_t err;
 
         /* send path length */
         nlen = GUINT32_TO_BE(pathlen);
-        err = mobilebackup2_send_raw(mobilebackup2, (const char*)&nlen, sizeof(nlen), (uint32_t*)&bytes);
+        err = mobilebackup2_send_raw(mobilebackup2, (const char*)&nlen, sizeof(nlen), &bytes);
         if (err != MOBILEBACKUP2_E_SUCCESS) {
                 goto leave_proto_err;
         }
-        if (bytes != sizeof(nlen)) {
+        if (bytes != (uint32_t)sizeof(nlen)) {
                 err = MOBILEBACKUP2_E_MUX_ERROR;
                 goto leave_proto_err;
         }
 
         /* send path */
-        err = mobilebackup2_send_raw(mobilebackup2, path, pathlen, (uint32_t*)&bytes);
+        err = mobilebackup2_send_raw(mobilebackup2, path, pathlen, &bytes);
         if (err != MOBILEBACKUP2_E_SUCCESS) {
                 goto leave_proto_err;
         }
-        if ((uint32_t)bytes != pathlen) {
+        if (bytes != pathlen) {
                 err = MOBILEBACKUP2_E_MUX_ERROR;
                 goto leave_proto_err;
         }
@@ -862,6 +866,17 @@ static int handle_send_file(const char *backup_dir, const char *path, plist_t *e
                 goto leave;
         }
 
+        total = fst.st_size;
+
+        gchar *format_size = g_format_size_for_display(total);
+        printf("Sending file '%s': (%s)\n", path, format_size);
+        g_free(format_size);
+
+        if (total == 0) {
+                errcode = 0;
+                goto leave;
+        }
+
         f = fopen(localfile, "rb");
         if (!f) {
                 printf("%s: Error opening local file '%s': %d\n", __func__, localfile, errno);
@@ -869,53 +884,50 @@ static int handle_send_file(const char *backup_dir, const char *path, plist_t *e
                 goto leave;
         }
 
-        printf("Sending file '%s'\n", path);
-
-        /* send data size (file size + 1) */
-        uint32_t length = (uint32_t)fst.st_size;
-        nlen = GUINT32_TO_BE(length+1);
-        memcpy(buf, &nlen, sizeof(nlen));
-        /* unknown special byte */
-        buf[4] = 0x0C;
-        err = mobilebackup2_send_raw(mobilebackup2, (const char*)buf, 5, (uint32_t*)&bytes);
-        if (err != MOBILEBACKUP2_E_SUCCESS) {
-                goto leave_proto_err;
-        }
-        if (bytes != 5) {
-                goto leave_proto_err;
-        }
+        sent = 0;
+        do {
+                length = ((total-sent) < (off_t)sizeof(buf)) ? (uint32_t)total-sent : (uint32_t)sizeof(buf);
+                /* send data size (file size + 1) */
+                nlen = GUINT32_TO_BE(length+1);
+                memcpy(buf, &nlen, sizeof(nlen));
+                buf[4] = CODE_FILE_DATA;
+                err = mobilebackup2_send_raw(mobilebackup2, (const char*)buf, 5, &bytes);
+                if (err != MOBILEBACKUP2_E_SUCCESS) {
+                        goto leave_proto_err;
+                }
+                if (bytes != 5) {
+                        goto leave_proto_err;
+                }
 
-        /* send file contents */
-        uint32_t sent = 0;
-        while (sent < length) {
+                /* send file contents */
                 size_t r = fread(buf, 1, sizeof(buf), f);
                 if (r <= 0) {
                         printf("%s: read error\n", __func__);
                         errcode = errno;
                         goto leave;
                 }
-                err = mobilebackup2_send_raw(mobilebackup2, buf, r, (uint32_t*)&bytes);
+                err = mobilebackup2_send_raw(mobilebackup2, buf, r, &bytes);
                 if (err != MOBILEBACKUP2_E_SUCCESS) {
                         goto leave_proto_err;
                 }
-                if ((uint32_t)bytes != r) {
-                        printf("sent only %d from %d\n", bytes, r);
+                if (bytes != (uint32_t)r) {
+                        printf("Error: sent only %d of %d bytes\n", bytes, (int)r);
                         goto leave_proto_err;
                 }
                 sent += r;
-        }
+        } while (sent < total);
         fclose(f);
         f = NULL;
         errcode = 0;
 
 leave:
         if (errcode == 0) {
-                e = 0;
+                result = 0;
                 nlen = 1;
                 nlen = GUINT32_TO_BE(nlen);
                 memcpy(buf, &nlen, 4);
-                buf[4] = 0;
-                mobilebackup2_send_raw(mobilebackup2, buf, 5, &sent);
+                buf[4] = CODE_SUCCESS;
+                mobilebackup2_send_raw(mobilebackup2, buf, 5, &bytes);
         } else {
                 if (!*errplist) {
                         *errplist = plist_new_dict();
@@ -926,15 +938,15 @@ leave:
                 length = strlen(errdesc);
                 nlen = GUINT32_TO_BE(length+1);
                 memcpy(buf, &nlen, 4);
-                buf[4] = 0x06;
+                buf[4] = CODE_ERROR_LOCAL;
                 slen = 5;
                 memcpy(buf+slen, errdesc, length);
                 slen += length;
-                err = mobilebackup2_send_raw(mobilebackup2, (const char*)buf, slen, (uint32_t*)&bytes);
+                err = mobilebackup2_send_raw(mobilebackup2, (const char*)buf, slen, &bytes);
                 if (err != MOBILEBACKUP2_E_SUCCESS) {
                         printf("could not send message\n");
                 }
-                if ((uint32_t)bytes != slen) {
+                if (bytes != slen) {
                         printf("could only send %d from %d\n", bytes, slen);
                 }
         }
@@ -943,7 +955,7 @@ leave_proto_err:
         if (f)
                 fclose(f);
         g_free(localfile);
-        return e;
+        return result;
 }
 
 static void handle_send_files(plist_t message, const char *backup_dir)
@@ -1050,7 +1062,7 @@ static int handle_receive_files(plist_t message, const char *backup_dir)
                 mobilebackup2_receive_raw(mobilebackup2, &code, 1, &r);
 
                 /* TODO remove this */
-                if ((code != 0) && (code != CODE_FILE_DATA) && (code != CODE_ERROR_MSG)) {
+                if ((code != CODE_SUCCESS) && (code != CODE_FILE_DATA) && (code != CODE_ERROR_REMOTE)) {
                         printf("Found new flag %02x\n", code);
                 }
 
@@ -1103,7 +1115,7 @@ static int handle_receive_files(plist_t message, const char *backup_dir)
                 }
 
                 /* check if an error message was received */
-                if (code == CODE_ERROR_MSG) {
+                if (code == CODE_ERROR_REMOTE) {
                         /* error message */
                         char *msg = (char*)malloc(nlen);
                         mobilebackup2_receive_raw(mobilebackup2, msg, nlen-1, &r);