dbox: Give more verbose error message about broken attachment ext-refs.

diff --git a/src/lib-storage/index/dbox-common/dbox-attachment.c b/src/lib-storage/index/dbox-common/dbox-attachment.c
index af70d1600708cc02b73e8b0345852626d4bee511..fe40a7b9fe7458d45c1c7a552bf5991e2ea1858a 100644 (file)
--- a/src/lib-storage/index/dbox-common/dbox-attachment.c
+++ b/src/lib-storage/index/dbox-common/dbox-attachment.c
@@ -139,7 +139,8 @@ bool dbox_attachment_parse_extref(const char *line, pool_t pool,
 static int
 dbox_attachment_file_get_stream_from(struct dbox_file *file,
                                     const char *ext_refs,
-                                    struct istream **stream)
+                                    struct istream **stream,
+                                    const char **error_r)
 {
        ARRAY_TYPE(mail_attachment_extref) extrefs_arr;
        ARRAY_DEFINE(streams, struct istream *);
@@ -150,10 +151,14 @@ dbox_attachment_file_get_stream_from(struct dbox_file *file,
        unsigned int i;
        int ret = 1;
 
+       *error_r = NULL;
+
        t_array_init(&extrefs_arr, 16);
        if (!dbox_attachment_parse_extref_real(ext_refs, pool_datastack_create(),
-                                              &extrefs_arr))
+                                              &extrefs_arr)) {
+               *error_r = "Broken ext-refs string";
                return 0;
+       }
        psize = dbox_file_get_plaintext_size(file);
 
        t_array_init(&streams, 8);
@@ -169,7 +174,10 @@ dbox_attachment_file_get_stream_from(struct dbox_file *file,
                        array_append(&streams, &input, 1);
                        i_stream_seek(*stream, (*stream)->v_offset + part_size);
                        if ((*stream)->v_offset + part_size > psize) {
-                               /* extrefs point outside message */
+                               *error_r = t_strdup_printf(
+                                       "ext-refs point outside message "
+                                       "(%"PRIuUOFF_T" + %"PRIuUOFF_T" > %"PRIuUOFF_T")",
+                                       (*stream)->v_offset, part_size, psize);
                                ret = 0;
                        }
                        last_voffset += part_size;
@@ -192,8 +200,11 @@ dbox_attachment_file_get_stream_from(struct dbox_file *file,
        }
 
        if (psize != (*stream)->v_offset) {
-               if (psize < (*stream)->v_offset) {
-                       /* extrefs point outside message */
+               if ((*stream)->v_offset > psize) {
+                       *error_r = t_strdup_printf(
+                               "ext-refs point outside message "
+                               "(%"PRIuUOFF_T" > %"PRIuUOFF_T")",
+                               (*stream)->v_offset, psize);
                        ret = 0;
                } else {
                        uoff_t trailer_size = psize - (*stream)->v_offset;
@@ -215,7 +226,7 @@ dbox_attachment_file_get_stream_from(struct dbox_file *file,
 int dbox_attachment_file_get_stream(struct dbox_file *file,
                                    struct istream **stream)
 {
-       const char *ext_refs;
+       const char *ext_refs, *error;
        int ret;
 
        /* need to read metadata in case there are external references */
@@ -231,11 +242,12 @@ int dbox_attachment_file_get_stream(struct dbox_file *file,
        /* we have external references. */
        T_BEGIN {
                ret = dbox_attachment_file_get_stream_from(file, ext_refs,
-                                                          stream);
+                                                          stream, &error);
+               if (ret == 0) {
+                       dbox_file_set_corrupted(file,
+                               "Corrupted ext-refs metadata %s: %s",
+                               ext_refs, error);
+               }
        } T_END;
-       if (ret == 0) {
-               dbox_file_set_corrupted(file, "Ext refs metadata corrupted: %s",
-                                       ext_refs);
-       }
        return ret;
 }