Network Buffers and Memory Management
Ethernet is probably the most common physical interface type that can be handled. The kernel provides a set of general purpose Ethernet support routines that such drivers can use.
eth_header() is the standard Ethernet handler for the dev-hard_header routine, and can be used in any Ethernet driver. Combined with eth_rebuild_header() for the rebuild routine it provides all the ARP lookup required to put Ethernet headers on IP packets.
The eth_type_trans() routine expects to be fed a raw Ethernet packet. It analyses the headers and sets skb->pkt_type and skb->mac itself as well as returning the suggested value for skb->protocol. This routine is normally called from the Ethernet driver receive interrupt handler to classify packets.
eth_copy_and_sum(), the final Ethernet support routine is internally quite complex, but offers significant performance improvements for memory mapped cards. It provides the support to copy and checksum data from the card into a sk_buff in a single pass. This single pass through memory almost eliminates the cost of checksum computation when used and improves IP throughput.
Alan Cox has been working on Linux since version 0.95, when he installed it in order to do further work on the AberMUD game. He now manages the Linux Networking, SMP, and Linux/8086 projects and hasn't done any work on AberMUD since November 1993.
|diff -u: What's New in Kernel Development||Aug 20, 2014|
|Security Hardening with Ansible||Aug 18, 2014|
|Monitoring Android Traffic with Wireshark||Aug 14, 2014|
|IndieBox: for Gamers Who Miss Boxes!||Aug 13, 2014|
|Non-Linux FOSS: a Virtualized Cisco Infrastructure?||Aug 11, 2014|
|Linux Security Threats on the Rise||Aug 08, 2014|
- diff -u: What's New in Kernel Development
- Security Hardening with Ansible
- NSA: Linux Journal is an "extremist forum" and its readers get flagged for extra surveillance
- New Products
- Tech Tip: Really Simple HTTP Server with Python
- Monitoring Android Traffic with Wireshark
- [<Megashare>] Watch Mrs Brown's Boys Movie Online Full Movie HD 2014
- RSS Feeds
- Linux Systems Administrator
- Technical Support Rep