]> wimlib.net Git - wimlib/blobdiff - src/symlink.c
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[wimlib] / src / symlink.c
index f16d8c22470e20f084434aa4df35c342ef705be3..ca2e422fca2176e49f6f6b1054bc0667736bcce0 100644 (file)
@@ -1,3 +1,9 @@
+/*
+ * symlink.c
+ *
+ * Code to read and set symbolic links in WIM files.
+ */
+
 /*
  * Copyright (C) 2012 Eric Biggers
  *
@@ -99,7 +105,12 @@ static ssize_t get_symlink_name(const u8 *resource, size_t resource_len,
                translated_target += 4;
                link_target_len -= 4;
                /* There's a drive letter, so just leave the backslashes since
-                * it won't go anyhwere on UNIX anyway... */
+                * it won't go anyhwere on UNIX anyway... 
+                *
+                * XXX
+                * NTFS-3g tries to re-map these links to actually point to
+                * something, so maybe we could do something like that here
+                * XXX*/
        } else {
                for (size_t i = 0; i < link_target_len; i++)
                        if (translated_target[i] == '\\')
@@ -131,9 +142,9 @@ void *make_symlink_reparse_data_buf(const char *symlink_target, size_t *len_ret)
        /* XXX Fix absolute paths */
 
        u8 *p = buf;
-       p = put_u16(p, 0); /* Substitute name offset */
+       p = put_u16(p, utf16_len); /* Substitute name offset */
        p = put_u16(p, utf16_len); /* Substitute name length */
-       p = put_u16(p, utf16_len); /* Print name offset */
+       p = put_u16(p, 0); /* Print name offset */
        p = put_u16(p, utf16_len); /* Print name length */
        p = put_u32(p, 1);
        p = put_bytes(p, utf16_len, name_utf16);
@@ -145,38 +156,15 @@ out:
        return buf;
 }
 
-static const struct lookup_table_entry *
-dentry_first_lte(const struct dentry *dentry, const struct lookup_table *table)
-{
-       const struct lookup_table_entry *lte;
-       if (dentry->resolved) {
-               if (dentry->lte)
-                       return dentry->lte;
-               for (u16 i = 0; i < dentry->num_ads; i++)
-                       if (dentry->ads_entries[i].lte)
-                               return dentry->ads_entries[i].lte;
-       } else {
-               const u8 *hash = dentry->hash;
-               u16 i = 0;
-               while (1) {
-                       if ((lte = __lookup_resource(table, hash)))
-                               break;
-                       if (i == dentry->num_ads)
-                               return NULL;
-                       hash = dentry->ads_entries[i].hash;
-                       i++;
-               }
-       }
-       return NULL;
-}
-
-/* Get the symlink target from a dentry that's already checked to be either a
- * "real" symlink or a junction point. */
+/* Get the symlink target from a dentry.
+ *
+ * The dentry may be either "real" symlink or a junction point.
+ */
 ssize_t dentry_readlink(const struct dentry *dentry, char *buf, size_t buf_len,
                        const WIMStruct *w)
 {
-       const struct resource_entry *res_entry;
        const struct lookup_table_entry *lte;
+       int ret;
 
        wimlib_assert(dentry_is_symlink(dentry));
 
@@ -184,45 +172,48 @@ ssize_t dentry_readlink(const struct dentry *dentry, char *buf, size_t buf_len,
        if (!lte)
                return -EIO;
 
-       res_entry = &lte->resource_entry;
-       if (res_entry->original_size > 10000)
+       if (wim_resource_size(lte) > 10000)
                return -EIO;
 
-       char __res_buf[res_entry->original_size];
-       const char *res_buf;
-       if (lte->is_symlink && lte->symlink_buf) {
-               res_buf = lte->symlink_buf;
-       } else {
-               res_buf = __res_buf;
-               if (read_full_resource(w->fp, res_entry->size, 
-                                      res_entry->original_size,
-                                      res_entry->offset,
-                                      wim_resource_compression_type(w, res_entry),
-                                      __res_buf) != 0)
-                       return -EIO;
-               res_buf = __res_buf;
-       }
-       return get_symlink_name(res_buf, res_entry->original_size, buf,
+       char res_buf[wim_resource_size(lte)];
+       ret = read_full_wim_resource(lte, res_buf);
+       if (ret != 0)
+               return -EIO;
+       return get_symlink_name(res_buf, wim_resource_size(lte), buf,
                                buf_len, dentry->reparse_tag);
 }
 
 static int dentry_set_symlink_buf(struct dentry *dentry,
-                                 const u8 symlink_buf_hash[])
+                                 struct lookup_table_entry *lte)
 {
        struct ads_entry *ads_entries;
 
        ads_entries = CALLOC(2, sizeof(struct ads_entry));
        if (!ads_entries)
                return WIMLIB_ERR_NOMEM;
-       memcpy(ads_entries[1].hash, symlink_buf_hash, WIM_HASH_SIZE);
+
        wimlib_assert(dentry->num_ads == 0);
-       wimlib_assert(!dentry->ads_entries);
+       wimlib_assert(dentry->ads_entries == NULL);
+
+       ads_entries[0].lte = lte;
+
        /*dentry_free_ads_entries(dentry);*/
        dentry->num_ads = 2;
        dentry->ads_entries = ads_entries;
        return 0;
 }
 
+/* 
+ * Sets @dentry to be a symbolic link pointing to @target.
+ *
+ * A lookup table entry for the symbolic link data buffer is created and
+ * inserted into @lookup_table, unless there is an existing lookup table entry
+ * for the exact same data, in which its reference count is incremented.
+ *
+ * The lookup table entry is returned in @lte_ret.
+ *
+ * On failure @dentry and @lookup_table are not modified.
+ */
 int dentry_set_symlink(struct dentry *dentry, const char *target,
                       struct lookup_table *lookup_table,
                       struct lookup_table_entry **lte_ret)
@@ -231,7 +222,7 @@ int dentry_set_symlink(struct dentry *dentry, const char *target,
        int ret;
        size_t symlink_buf_len;
        struct lookup_table_entry *lte = NULL, *existing_lte;
-       u8 symlink_buf_hash[WIM_HASH_SIZE];
+       u8 symlink_buf_hash[SHA1_HASH_SIZE];
        void *symlink_buf;
        
        symlink_buf = make_symlink_reparse_data_buf(target, &symlink_buf_len);
@@ -239,15 +230,16 @@ int dentry_set_symlink(struct dentry *dentry, const char *target,
                return WIMLIB_ERR_NOMEM;
 
        DEBUG("Made symlink reparse data buf (len = %zu, name len = %zu)",
-                       symlink_buf_len, ret);
+                       symlink_buf_len, symlink_buf_len);
        
        sha1_buffer(symlink_buf, symlink_buf_len, symlink_buf_hash);
 
        existing_lte = __lookup_resource(lookup_table, symlink_buf_hash);
 
        if (existing_lte) {
-               existing_lte->refcnt++;
                lte = existing_lte;
+               FREE(symlink_buf);
+               symlink_buf = NULL;
        } else {
                DEBUG("Creating new lookup table entry for symlink buf");
                lte = new_lookup_table_entry();
@@ -255,21 +247,26 @@ int dentry_set_symlink(struct dentry *dentry, const char *target,
                        ret = WIMLIB_ERR_NOMEM;
                        goto out_free_symlink_buf;
                }
-               lte->is_symlink = true;
-               lte->symlink_buf = symlink_buf;
+               lte->resource_location            = RESOURCE_IN_ATTACHED_BUFFER;
+               lte->attached_buffer              = symlink_buf;
                lte->resource_entry.original_size = symlink_buf_len;
-               lte->resource_entry.size = symlink_buf_len;
-               memcpy(lte->hash, symlink_buf_hash, WIM_HASH_SIZE);
+               lte->resource_entry.size          = symlink_buf_len;
+               lte->resource_entry.flags         = 0;
+               copy_hash(lte->hash, symlink_buf_hash);
        }
 
-       ret = dentry_set_symlink_buf(dentry, symlink_buf_hash);
+       ret = dentry_set_symlink_buf(dentry, lte);
 
        if (ret != 0)
                goto out_free_lte;
 
+       dentry->resolved = true;
+
        DEBUG("Loaded symlink buf");
 
-       if (!existing_lte)
+       if (existing_lte)
+               lte->refcnt++;
+       else
                lookup_table_insert(lookup_table, lte);
        if (lte_ret)
                *lte_ret = lte;