Understanding Linux Network Internals 2005 phần 3 pptx

... used by the drivers/net/3c59x.c driver): outsl(ioaddr + TX_FIFO, skb->data, (skb->len + 3) >> 2); dev_kfree_skb (skb); if (inw(ioaddr + TxFree) > 1 536 ) { netif_start_queue ... has room for max-sized packet. */ netif_stop_queue(dev); outw(SetTxThreshold + (1 536 >>2), ioaddr + EL3_CMD); This document was created by an unregistered ChmMagic, please go to http://ww...

Ngày tải lên: 13/08/2014, 04:21

... Overview of Network Stack Section 13. 2. Executing the Right Protocol Handler Section 13. 3. Protocol Handler Organization Section 13. 4. Protocol Handler Registration Section 13. 5. Ethernet ... Section 35 .2. Helper Routines Section 35 .3. The Table Lookup: fn_hash_lookup Section 35 .4. fib_lookup Function Section 35 .5. Setting Functions for Reception and T...

Ngày tải lên: 13/08/2014, 04:21

... registers the associated network device. In this case, device Dev3 needs an additional device driver, called B. When driver B eventually registers with the kernel, Dev3 will be assigned to it. ... 0x20115 MODULE_AUTHOR("Donald Becker <becker@cesdis.gsfc.nasa.gov>"); MODULE_DESCRIPTION("3Com 3c590/3c900 series Vortex/Boomerang driver"); MODULE_PARM(debug, "i&...

Ngày tải lên: 13/08/2014, 04:21

... ID BR2 A port ID of 2 Now let's add a new bridge named BR3, and assume that Bridge ID BR3 < Bridge ID BR4, as in Figure 15- 13. As we explained in the section "Root Bridge Selection," ... topology in Figure 16-2, if we added one more subnet (10.0 .3. 0/24) and configured eth0 with an address on it, the topology would appear to the Linux kernel routing layer like the one...

Ngày tải lên: 13/08/2014, 04:21

... and code. 18.4 .3. 3. Example of IP ID generation The wraparound problem is partially addressed by means of multiple, concurrent, global counters. Instead of a global IP ID, the Linux kernel ... "Fragmentation and reassembly"). See also the section "Expiration Criteria" in Chapter 33 . In Linux, the ip_dont_fragment function (shown in Chapter 22) uses the considerat...

Ngày tải lên: 13/08/2014, 04:21

... www.oreilly.com (208.201. 239 .36 ) 56(84) bytes of data 64 bytes from www.oreillynet.com (208.201. 239 .36 ): icmp_seq=0 ttl=50 time=245 ms 64 bytes from www.oreillynet.com (208.201. 239 .36 ): icmp_seq=1 ttl=50 ... sk_buff *skb, u32 info) Function used by the ICMP protocol handler to inform the L4 protocol about the reception of an ICMP UNREACHABLE message. We will see in Chapter 35 when...

Ngày tải lên: 13/08/2014, 04:21

... notify the neighboring subsystem about changes to devices and L3 addresses. Notifications about changes to L3 addresses are sent by L3 protocols. neigh_changeaddr A function that neighboring protocols ... 29. Header caching at the L2 layer is tied to caching by the routing subsystem at the L3 layer, described in Chapter 33 . As shown in Figure 27-1, each dst_entry element of the IPv4 routi...

Ngày tải lên: 13/08/2014, 04:21

... implications of the setups in Figure 30 -4(b) and 30 -4(c) on lower-layer neighboring protocols. In this chapter, we will look at the implications with regard to routing . 30 .1 .3. Questions Answered in This ... ipv4_devconf structure, which is defined in include /linux/ inetdevice.h. Not all of its fields are used by the neighboring protocols (see Chapters 23 and 36 for the other fie...

Ngày tải lên: 13/08/2014, 04:21

... Notifications" in Chapter 32 ). 34 .3. 1. Adding a Route The insertion of a new route is taken care of by fn_hash_insert, whose logic is described in Figures 34 -3( a) and 34 -3( b). [*] This routine ... function, described in the section "Interface Between the DST and Calling Protocols." 33 .3. 3. Adding Elements to the Cache Every time a cache lookup required to route...

Ngày tải lên: 13/08/2014, 04:21

... initialized, they are set to zero. u32 r_src u32 r_srcmask IP address and netmask, respectively, of the source network from which packets must come. u32 r_dst u32 r_dstmask IP address and netmask, ... Chapter 33 . fib_tables List of fib_table instances. See Figure 34 -1 in Chapter 34 . fib_rules List of routing policies. See the section "fib_lookup with Policy Routing" in Chapt...

Ngày tải lên: 13/08/2014, 04:21