Changeset 50986 in vbox for trunk/src/VBox/Devices/Network/slirp

Timestamp:

Apr 7, 2014 4:12:55 PM (11 years ago)

Author:

vboxsync

Message:

NAT: Update function comment for icmp_error to reflect r93155 (it was
already out of sync with the code after r91460).

File:

• trunk/src/VBox/Devices/Network/slirp/ip_icmp.c (modified) (1 diff)

trunk/src/VBox/Devices/Network/slirp/ip_icmp.c

@@ -600 +600 @@
  * It is reported as the bad ip packet.  The header should
  * be fully correct and in host byte order.
- * ICMP fragmentation is illegal.  All machines must accept 576 bytes in one
- * packet.  The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
- * @note: implementation note: MSIZE is 256 bytes (minimal buffer), m_getjcl we allocate two mbufs on: clust_zone 
- * and mbuf_zone. the maximum payload 256 - 14 (Ethernet header) - 20 (IPv4 hdr) - 8 (ICMPv4 header) = 214
+ * ICMP fragmentation is illegal.
+ *
+ * @note: implementation note: MSIZE is 256 bytes (minimal buffer).
+ * We always truncate original payload to 8 bytes required by the RFC,
+ * so the largest possible datagram is 14 (ethernet) + 20 (ip) +
+ * 8 (icmp) + 60 (max original ip with options) + 8 (original payload)
+ * = 110 bytes which fits into sinlge mbuf.
  *
  * @note This function will free msrc!