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Netatalk · Feb 15, 2025 · 5b81d6f · 5b81d6f
1 parent 4cdc09f
commit 5b81d6f
Showing 1 changed file with 49 additions and 74 deletions.
diff --git a/libatalk/vfs/ea_ad.c b/libatalk/vfs/ea_ad.c
@@ -120,106 +120,81 @@ static char *mtoupath(const struct vol *vol, const char *mpath)
  *
  * Verifies magic and version.
  */
-static int unpack_header(struct ea * restrict ea)
+static int pack_header(struct ea * restrict ea)
 {
-    int ret = 0;
-    unsigned int count = 0;
+    unsigned int count = 0, eacount = 0;
     uint16_t uint16;
     uint32_t uint32;
-    char *buf;
-    size_t remaining;
-
-    /* Check magic and version */
-    buf = ea->ea_data;
-    memcpy(&uint32, buf, sizeof(uint32_t));
-    if (uint32 != htonl(EA_MAGIC)) {
-        LOG(log_error, logtype_afpd, "unpack_header: wrong magic 0x%08x", uint32);
-        ret = -1;
-        goto exit;
-    }
-    buf += 4;
-    memcpy(&uint16, buf, sizeof(uint16_t));
-    if (uint16 != htons(EA_VERSION)) {
-        LOG(log_error, logtype_afpd, "unpack_header: wrong version 0x%04x", uint16);
-        ret = -1;
-        goto exit;
-    }
-    buf += 2;
+    size_t bufsize = EA_HEADER_SIZE;
 
-    /* Get EA count */
-    memcpy(&uint16, buf, sizeof(uint16_t));
-    ea->ea_count = ntohs(uint16);
-    LOG(log_debug, logtype_afpd, "unpack_header: number of EAs: %u", ea->ea_count);
-    buf += 2;
+    char *buf = ea->ea_data + EA_HEADER_SIZE;
+
+    LOG(log_debug, logtype_afpd, "pack_header('%s'): ea_count: %u, ea_size: %u",
+        ea->filename, ea->ea_count, ea->ea_size);
 
     if (ea->ea_count == 0)
+        /* nothing to do, magic, version and count are still valid in buffer */
         return 0;
 
-    /* Check magic and version */
-    buf = ea->ea_data;
-    remaining = ea->ea_size;
+    while(count < ea->ea_count) { /* the names */
+        /* Check if its a deleted entry */
+        if ( ! ((*ea->ea_entries)[count].ea_name)) {
+            count++;
+            continue;
+        }
 
-    if (remaining < EA_HEADER_SIZE) {
-        ret = -1;
-        goto exit;
+        bufsize += (*(ea->ea_entries))[count].ea_namelen + 1;
+        count++;
+        eacount++;
     }
 
-    /* Allocate storage for the ea_entries array */
-    ea->ea_entries = malloc(sizeof(struct ea_entry) * ea->ea_count);
-    if ( ! ea->ea_entries) {
-        LOG(log_error, logtype_afpd, "unpack_header: OOM");
-        ret = -1;
-        goto exit;
+    bufsize += (eacount * 4); /* header + ea_size for each EA */
+    if (bufsize > ea->ea_size) {
+        /* we must realloc */
+        if ( ! (buf = realloc(ea->ea_data, bufsize)) ) {
+            LOG(log_error, logtype_afpd, "pack_header: OOM");
+            return -1;
+        }
+        ea->ea_data = buf;
     }
+    ea->ea_size = bufsize;
 
+    /* copy count */
+    uint16 = htons(eacount);
+    memcpy(ea->ea_data + EA_COUNT_OFF, &uint16, 2);
+
+    count = 0;
+    buf = ea->ea_data + EA_HEADER_SIZE;
     while (count < ea->ea_count) {
-        /* Check if we have enough bytes for EA size (4) + at least 1 char for name */
-        if (remaining < 5) {
-            ret = -1;
-            goto cleanup;
+        /* Check if its a deleted entry */
+        if ( ! ((*ea->ea_entries)[count].ea_name)) {
+            count++;
+            continue;
         }
-
-        memcpy(&uint32, buf, 4); /* EA size */
-        buf += 4;
-        remaining -= 4;
 
-        /* Validate string length fits in remaining buffer */
-        size_t namelen = strnlen(buf, remaining);
-        if (namelen == remaining) { /* No null terminator found */
-            ret = -1;
-            goto cleanup;
-        }
+        /* First: EA size */
+        uint32 = htonl((*(ea->ea_entries))[count].ea_size);
+        memcpy(buf, &uint32, 4);
+        buf += 4;
 
-        /* Rest of the existing code */
-        (*(ea->ea_entries))[count].ea_size = ntohl(uint32);
-        (*(ea->ea_entries))[count].ea_name = strdup(buf);
-        if (! (*(ea->ea_entries))[count].ea_name) {
-            ret = -1;
-            goto cleanup;
-        }
-
-        (*(ea->ea_entries))[count].ea_namelen = namelen;
-        buf += namelen + 1;
-        remaining -= namelen + 1;
+        /* Second: EA name as C-string */
+        strcpy(buf, (*(ea->ea_entries))[count].ea_name);
+        buf += (*(ea->ea_entries))[count].ea_namelen + 1;
 
-        LOG(log_maxdebug, logtype_afpd, "unpack_header: entry no:%u,\"%s\", size: %u, namelen: %u", count,
+        LOG(log_maxdebug, logtype_afpd, "pack_header: entry no:%u,\"%s\", size: %u, namelen: %u", count,
             (*(ea->ea_entries))[count].ea_name,
             (*(ea->ea_entries))[count].ea_size,
             (*(ea->ea_entries))[count].ea_namelen);
 
         count++;
     }
 
-cleanup:
-    while (count > 0) {
-        count--;
-        free((*(ea->ea_entries))[count].ea_name);
-    }
-    free(ea->ea_entries);
-    ea->ea_entries = NULL;
+    ea->ea_count = eacount;
 
-exit:
-    return ret;
+    LOG(log_debug, logtype_afpd, "pack_header('%s'): ea_count: %u, ea_size: %u",
+        ea->filename, ea->ea_count, ea->ea_size);
+
+    return 0;
 }
 
 /*