commit 233af7d7b30b53c99427ab4db077c6081b12559f
author Fabio Utzig <utzig@apache.org> Mon Aug 26 12:06:16 2019 -0300
committer Fabio Utzig <utzig@utzig.org> Mon Sep 09 10:00:09 2019 -0300
tree aebcf196b300ed08da8b4ec05288b36dac7468e3
parent a87cc7d98c4512e86ac012538cbd499158819d85

Add utility function to find offset/len of TLVs

Add a new function, boot_find_tlv_offs, that loads the beginning and end
offset of the TLV region.

Signed-off-by: Fabio Utzig <utzig@apache.org>

boot/bootutil/src/loader.c

diff --git a/boot/bootutil/src/loader.c b/boot/bootutil/src/loader.c
index 99cf186..71ebb11 100644
--- a/boot/bootutil/src/loader.c
+++ b/boot/bootutil/src/loader.c
@@ -243,6 +243,38 @@
 }
 
 /*
+ * Locate the TLVs in an image.
+ *
+ * @param hdr The image_header struct of the image being checked
+ * @param fap flash_area struct of the slot storing the image being checked
+ * @param off Address of the first TLV (after TLV info)
+ * @param end Address where TLV area ends
+ *
+ * Returns 0 on success.
+ */
+int
+boot_find_tlv_offs(const struct image_header *hdr, const struct flash_area *fap,
+        uint32_t *off, uint32_t *end)
+{
+    struct image_tlv_info info;
+    uint32_t off_;
+
+    off_ = BOOT_TLV_OFF(hdr);
+
+    if (flash_area_read(fap, off_, &info, sizeof(info))) {
+        return BOOT_EFLASH;
+    }
+
+    if (info.it_magic != IMAGE_TLV_INFO_MAGIC) {
+        return BOOT_EBADIMAGE;
+    }
+
+    *end = off_ + info.it_tlv_tot;
+    *off = off_ + sizeof(info);
+    return 0;
+}
+
+/*
  * Compute the total size of the given image.  Includes the size of
  * the TLVs.
  */
@@ -251,8 +283,7 @@
 boot_read_image_size(struct boot_loader_state *state, int slot, uint32_t *size)
 {
     const struct flash_area *fap;
-    struct image_tlv_info info;
-    uint32_t tlv_off;
+    uint32_t off;
     int area_id;
     int rc;
 
@@ -267,17 +298,10 @@
         goto done;
     }
 
-    tlv_off = BOOT_TLV_OFF(boot_img_hdr(state, slot));
-    rc = flash_area_read(fap, tlv_off, &info, sizeof(info));
+    rc = boot_find_tlv_offs(boot_img_hdr(state, slot), fap, &off, size);
     if (rc != 0) {
-        rc = BOOT_EFLASH;
         goto done;
     }
-    if (info.it_magic != IMAGE_TLV_INFO_MAGIC) {
-        rc = BOOT_EBADIMAGE;
-        goto done;
-    }
-    *size = tlv_off + info.it_tlv_tot;
     rc = 0;
 
 done:
@@ -1821,7 +1845,6 @@
 boot_verify_all_dependency(struct boot_loader_state *state, uint32_t slot)
 {
     const struct flash_area *fap;
-    struct image_tlv_info info;
     struct image_tlv tlv;
     struct image_dependency dep;
     uint32_t off;
@@ -1837,22 +1860,11 @@
         goto done;
     }
 
-    off = BOOT_TLV_OFF(boot_img_hdr(state, slot));
-
-    /* The TLV area always starts with an image_tlv_info structure. */
-    rc = flash_area_read(fap, off, &info, sizeof(info));
+    rc = boot_find_tlv_offs(boot_img_hdr(state, slot), fap, &off, &end);
     if (rc != 0) {
-        rc = BOOT_EFLASH;
         goto done;
     }
 
-    if (info.it_magic != IMAGE_TLV_INFO_MAGIC) {
-        rc = BOOT_EBADIMAGE;
-        goto done;
-    }
-    end = off + info.it_tlv_tot;
-    off += sizeof(info);
-
     /* Traverse through all of the TLVs to find the dependency TLVs. */
     for (; off < end; off += sizeof(tlv) + tlv.it_len) {
         rc = flash_area_read(fap, off, &tlv, sizeof(tlv));