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ipxe/src/net/ipv4.c

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/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
* Copyright (C) 2006 Nikhil Chandru Rao
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
#include <string.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <byteswap.h>
#include <ipxe/list.h>
#include <ipxe/in.h>
#include <ipxe/arp.h>
#include <ipxe/if_ether.h>
#include <ipxe/iobuf.h>
#include <ipxe/netdevice.h>
#include <ipxe/ip.h>
#include <ipxe/tcpip.h>
#include <ipxe/dhcp.h>
#include <ipxe/settings.h>
#include <ipxe/fragment.h>
#include <ipxe/ipstat.h>
#include <ipxe/profile.h>
/** @file
*
* IPv4 protocol
*
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
/* Unique IP datagram identification number (high byte) */
static uint8_t next_ident_high = 0;
/** List of IPv4 miniroutes */
struct list_head ipv4_miniroutes = LIST_HEAD_INIT ( ipv4_miniroutes );
/** IPv4 statistics */
static struct ip_statistics ipv4_stats;
/** IPv4 statistics family */
struct ip_statistics_family
ipv4_stats_family __ip_statistics_family ( IP_STATISTICS_IPV4 ) = {
.version = 4,
.stats = &ipv4_stats,
};
/** Transmit profiler */
static struct profiler ipv4_tx_profiler __profiler = { .name = "ipv4.tx" };
/** Receive profiler */
static struct profiler ipv4_rx_profiler __profiler = { .name = "ipv4.rx" };
/**
* Add IPv4 minirouting table entry
*
* @v netdev Network device
* @v address IPv4 address
* @v netmask Subnet mask
* @v gateway Gateway address (if any)
* @ret rc Return status code
*/
static int add_ipv4_miniroute ( struct net_device *netdev,
struct in_addr address, struct in_addr netmask,
struct in_addr gateway ) {
struct ipv4_miniroute *miniroute;
DBGC ( netdev, "IPv4 add %s", inet_ntoa ( address ) );
DBGC ( netdev, "/%s ", inet_ntoa ( netmask ) );
if ( gateway.s_addr )
DBGC ( netdev, "gw %s ", inet_ntoa ( gateway ) );
DBGC ( netdev, "via %s\n", netdev->name );
/* Allocate and populate miniroute structure */
miniroute = malloc ( sizeof ( *miniroute ) );
if ( ! miniroute ) {
DBGC ( netdev, "IPv4 could not add miniroute\n" );
return -ENOMEM;
}
/* Record routing information */
miniroute->netdev = netdev_get ( netdev );
miniroute->address = address;
miniroute->netmask = netmask;
miniroute->gateway = gateway;
/* Add to end of list if we have a gateway, otherwise
* to start of list.
*/
if ( gateway.s_addr ) {
list_add_tail ( &miniroute->list, &ipv4_miniroutes );
} else {
list_add ( &miniroute->list, &ipv4_miniroutes );
}
return 0;
}
/**
* Delete IPv4 minirouting table entry
*
* @v miniroute Routing table entry
*/
static void del_ipv4_miniroute ( struct ipv4_miniroute *miniroute ) {
struct net_device *netdev = miniroute->netdev;
DBGC ( netdev, "IPv4 del %s", inet_ntoa ( miniroute->address ) );
DBGC ( netdev, "/%s ", inet_ntoa ( miniroute->netmask ) );
if ( miniroute->gateway.s_addr )
DBGC ( netdev, "gw %s ", inet_ntoa ( miniroute->gateway ) );
DBGC ( netdev, "via %s\n", miniroute->netdev->name );
netdev_put ( miniroute->netdev );
list_del ( &miniroute->list );
free ( miniroute );
}
/**
* Perform IPv4 routing
*
* @v scope_id Destination address scope ID
* @v dest Final destination address
* @ret dest Next hop destination address
* @ret miniroute Routing table entry to use, or NULL if no route
*
* If the route requires use of a gateway, the next hop destination
* address will be overwritten with the gateway address.
*/
static struct ipv4_miniroute * ipv4_route ( unsigned int scope_id,
struct in_addr *dest ) {
struct ipv4_miniroute *miniroute;
/* Find first usable route in routing table */
list_for_each_entry ( miniroute, &ipv4_miniroutes, list ) {
/* Skip closed network devices */
if ( ! netdev_is_open ( miniroute->netdev ) )
continue;
if ( IN_IS_MULTICAST ( dest->s_addr ) ) {
/* If destination is non-global, and the scope ID
* matches this network device, then use this route.
*/
if ( miniroute->netdev->index == scope_id )
return miniroute;
} else {
/* If destination is an on-link global
* address, then use this route.
*/
if ( ( ( dest->s_addr ^ miniroute->address.s_addr )
& miniroute->netmask.s_addr ) == 0 )
return miniroute;
/* If destination is an off-link global
* address, and we have a default gateway,
* then use this route.
*/
if ( miniroute->gateway.s_addr ) {
*dest = miniroute->gateway;
return miniroute;
}
}
}
return NULL;
}
/**
* Determine transmitting network device
*
* @v st_dest Destination network-layer address
* @ret netdev Transmitting network device, or NULL
*/
static struct net_device * ipv4_netdev ( struct sockaddr_tcpip *st_dest ) {
struct sockaddr_in *sin_dest = ( ( struct sockaddr_in * ) st_dest );
struct in_addr dest = sin_dest->sin_addr;
struct ipv4_miniroute *miniroute;
/* Find routing table entry */
miniroute = ipv4_route ( sin_dest->sin_scope_id, &dest );
if ( ! miniroute )
return NULL;
return miniroute->netdev;
}
/**
* Check if IPv4 fragment matches fragment reassembly buffer
*
* @v fragment Fragment reassembly buffer
* @v iobuf I/O buffer
* @v hdrlen Length of non-fragmentable potion of I/O buffer
* @ret is_fragment Fragment matches this reassembly buffer
*/
static int ipv4_is_fragment ( struct fragment *fragment,
struct io_buffer *iobuf,
size_t hdrlen __unused ) {
struct iphdr *frag_iphdr = fragment->iobuf->data;
struct iphdr *iphdr = iobuf->data;
return ( ( iphdr->src.s_addr == frag_iphdr->src.s_addr ) &&
( iphdr->ident == frag_iphdr->ident ) );
}
/**
* Get IPv4 fragment offset
*
* @v iobuf I/O buffer
* @v hdrlen Length of non-fragmentable potion of I/O buffer
* @ret offset Offset
*/
static size_t ipv4_fragment_offset ( struct io_buffer *iobuf,
size_t hdrlen __unused ) {
struct iphdr *iphdr = iobuf->data;
return ( ( ntohs ( iphdr->frags ) & IP_MASK_OFFSET ) << 3 );
}
/**
* Check if more fragments exist
*
* @v iobuf I/O buffer
* @v hdrlen Length of non-fragmentable potion of I/O buffer
* @ret more_frags More fragments exist
*/
static int ipv4_more_fragments ( struct io_buffer *iobuf,
size_t hdrlen __unused ) {
struct iphdr *iphdr = iobuf->data;
return ( iphdr->frags & htons ( IP_MASK_MOREFRAGS ) );
}
/** IPv4 fragment reassembler */
static struct fragment_reassembler ipv4_reassembler = {
.list = LIST_HEAD_INIT ( ipv4_reassembler.list ),
.is_fragment = ipv4_is_fragment,
.fragment_offset = ipv4_fragment_offset,
.more_fragments = ipv4_more_fragments,
.stats = &ipv4_stats,
};
/**
* Add IPv4 pseudo-header checksum to existing checksum
*
* @v iobuf I/O buffer
* @v csum Existing checksum
* @ret csum Updated checksum
*/
static uint16_t ipv4_pshdr_chksum ( struct io_buffer *iobuf, uint16_t csum ) {
struct ipv4_pseudo_header pshdr;
struct iphdr *iphdr = iobuf->data;
size_t hdrlen = ( ( iphdr->verhdrlen & IP_MASK_HLEN ) * 4 );
/* Build pseudo-header */
pshdr.src = iphdr->src;
pshdr.dest = iphdr->dest;
pshdr.zero_padding = 0x00;
pshdr.protocol = iphdr->protocol;
pshdr.len = htons ( iob_len ( iobuf ) - hdrlen );
/* Update the checksum value */
return tcpip_continue_chksum ( csum, &pshdr, sizeof ( pshdr ) );
}
/**
* Transmit IP packet
*
* @v iobuf I/O buffer
* @v tcpip Transport-layer protocol
* @v st_src Source network-layer address
* @v st_dest Destination network-layer address
* @v netdev Network device to use if no route found, or NULL
* @v trans_csum Transport-layer checksum to complete, or NULL
* @ret rc Status
*
* This function expects a transport-layer segment and prepends the IP header
*/
static int ipv4_tx ( struct io_buffer *iobuf,
struct tcpip_protocol *tcpip_protocol,
struct sockaddr_tcpip *st_src,
struct sockaddr_tcpip *st_dest,
struct net_device *netdev,
uint16_t *trans_csum ) {
struct iphdr *iphdr = iob_push ( iobuf, sizeof ( *iphdr ) );
struct sockaddr_in *sin_src = ( ( struct sockaddr_in * ) st_src );
struct sockaddr_in *sin_dest = ( ( struct sockaddr_in * ) st_dest );
struct ipv4_miniroute *miniroute;
struct in_addr next_hop;
struct in_addr netmask = { .s_addr = 0 };
uint8_t ll_dest_buf[MAX_LL_ADDR_LEN];
const void *ll_dest;
int rc;
/* Start profiling */
profile_start ( &ipv4_tx_profiler );
/* Update statistics */
ipv4_stats.out_requests++;
/* Fill up the IP header, except source address */
memset ( iphdr, 0, sizeof ( *iphdr ) );
iphdr->verhdrlen = ( IP_VER | ( sizeof ( *iphdr ) / 4 ) );
iphdr->service = IP_TOS;
iphdr->len = htons ( iob_len ( iobuf ) );
iphdr->ttl = IP_TTL;
iphdr->protocol = tcpip_protocol->tcpip_proto;
iphdr->dest = sin_dest->sin_addr;
/* Use routing table to identify next hop and transmitting netdev */
next_hop = iphdr->dest;
if ( sin_src )
iphdr->src = sin_src->sin_addr;
if ( ( next_hop.s_addr != INADDR_BROADCAST ) &&
( ( miniroute = ipv4_route ( sin_dest->sin_scope_id,
&next_hop ) ) != NULL ) ) {
iphdr->src = miniroute->address;
netmask = miniroute->netmask;
netdev = miniroute->netdev;
}
if ( ! netdev ) {
DBGC ( sin_dest->sin_addr, "IPv4 has no route to %s\n",
inet_ntoa ( iphdr->dest ) );
ipv4_stats.out_no_routes++;
rc = -ENETUNREACH;
goto err;
}
/* (Ab)use the "ident" field to convey metadata about the
* network device statistics into packet traces. Useful for
* extracting debug information from non-debug builds.
*/
iphdr->ident = htons ( ( (++next_ident_high) << 8 ) |
( ( netdev->rx_stats.bad & 0xf ) << 4 ) |
( ( netdev->rx_stats.good & 0xf ) << 0 ) );
/* Fix up checksums */
if ( trans_csum ) {
*trans_csum = ipv4_pshdr_chksum ( iobuf, *trans_csum );
if ( ! *trans_csum )
*trans_csum = tcpip_protocol->zero_csum;
}
iphdr->chksum = tcpip_chksum ( iphdr, sizeof ( *iphdr ) );
/* Print IP4 header for debugging */
DBGC2 ( sin_dest->sin_addr, "IPv4 TX %s->", inet_ntoa ( iphdr->src ) );
DBGC2 ( sin_dest->sin_addr, "%s len %d proto %d id %04x csum %04x\n",
inet_ntoa ( iphdr->dest ), ntohs ( iphdr->len ),
iphdr->protocol, ntohs ( iphdr->ident ),
ntohs ( iphdr->chksum ) );
/* Calculate link-layer destination address, if possible */
if ( ( ( next_hop.s_addr ^ INADDR_BROADCAST ) & ~netmask.s_addr ) == 0){
/* Broadcast address */
ipv4_stats.out_bcast_pkts++;
ll_dest = netdev->ll_broadcast;
} else if ( IN_IS_MULTICAST ( next_hop.s_addr ) ) {
/* Multicast address */
ipv4_stats.out_mcast_pkts++;
if ( ( rc = netdev->ll_protocol->mc_hash ( AF_INET, &next_hop,
ll_dest_buf ) ) !=0){
DBGC ( sin_dest->sin_addr, "IPv4 could not hash "
"multicast %s: %s\n",
inet_ntoa ( next_hop ), strerror ( rc ) );
goto err;
}
ll_dest = ll_dest_buf;
} else {
/* Unicast address */
ll_dest = NULL;
}
/* Update statistics */
ipv4_stats.out_transmits++;
ipv4_stats.out_octets += iob_len ( iobuf );
/* Hand off to link layer (via ARP if applicable) */
if ( ll_dest ) {
if ( ( rc = net_tx ( iobuf, netdev, &ipv4_protocol, ll_dest,
netdev->ll_addr ) ) != 0 ) {
DBGC ( sin_dest->sin_addr, "IPv4 could not transmit "
"packet via %s: %s\n",
netdev->name, strerror ( rc ) );
return rc;
}
} else {
if ( ( rc = arp_tx ( iobuf, netdev, &ipv4_protocol, &next_hop,
&iphdr->src, netdev->ll_addr ) ) != 0 ) {
DBGC ( sin_dest->sin_addr, "IPv4 could not transmit "
"packet via %s: %s\n",
netdev->name, strerror ( rc ) );
return rc;
}
}
profile_stop ( &ipv4_tx_profiler );
return 0;
err:
free_iob ( iobuf );
return rc;
}
/**
* Check if network device has any IPv4 address
*
* @v netdev Network device
* @ret has_any_addr Network device has any IPv4 address
*/
int ipv4_has_any_addr ( struct net_device *netdev ) {
struct ipv4_miniroute *miniroute;
list_for_each_entry ( miniroute, &ipv4_miniroutes, list ) {
if ( miniroute->netdev == netdev )
return 1;
}
return 0;
}
/**
* Check if network device has a specific IPv4 address
*
* @v netdev Network device
* @v addr IPv4 address
* @ret has_addr Network device has this IPv4 address
*/
static int ipv4_has_addr ( struct net_device *netdev, struct in_addr addr ) {
struct ipv4_miniroute *miniroute;
list_for_each_entry ( miniroute, &ipv4_miniroutes, list ) {
if ( ( miniroute->netdev == netdev ) &&
( miniroute->address.s_addr == addr.s_addr ) ) {
/* Found matching address */
return 1;
}
}
return 0;
}
/**
* Process incoming packets
*
* @v iobuf I/O buffer
* @v netdev Network device
* @v ll_dest Link-layer destination address
* @v ll_source Link-layer destination source
* @v flags Packet flags
* @ret rc Return status code
*
* This function expects an IP4 network datagram. It processes the headers
* and sends it to the transport layer.
*/
static int ipv4_rx ( struct io_buffer *iobuf,
struct net_device *netdev,
const void *ll_dest __unused,
const void *ll_source __unused,
unsigned int flags ) {
struct iphdr *iphdr = iobuf->data;
size_t hdrlen;
size_t len;
union {
struct sockaddr_in sin;
struct sockaddr_tcpip st;
} src, dest;
uint16_t csum;
uint16_t pshdr_csum;
int rc;
/* Start profiling */
profile_start ( &ipv4_rx_profiler );
/* Update statistics */
ipv4_stats.in_receives++;
ipv4_stats.in_octets += iob_len ( iobuf );
if ( flags & LL_BROADCAST ) {
ipv4_stats.in_bcast_pkts++;
} else if ( flags & LL_MULTICAST ) {
ipv4_stats.in_mcast_pkts++;
}
/* Sanity check the IPv4 header */
if ( iob_len ( iobuf ) < sizeof ( *iphdr ) ) {
DBGC ( iphdr->src, "IPv4 packet too short at %zd bytes (min "
"%zd bytes)\n", iob_len ( iobuf ), sizeof ( *iphdr ) );
goto err_header;
}
if ( ( iphdr->verhdrlen & IP_MASK_VER ) != IP_VER ) {
DBGC ( iphdr->src, "IPv4 version %#02x not supported\n",
iphdr->verhdrlen );
goto err_header;
}
hdrlen = ( ( iphdr->verhdrlen & IP_MASK_HLEN ) * 4 );
if ( hdrlen < sizeof ( *iphdr ) ) {
DBGC ( iphdr->src, "IPv4 header too short at %zd bytes (min "
"%zd bytes)\n", hdrlen, sizeof ( *iphdr ) );
goto err_header;
}
if ( hdrlen > iob_len ( iobuf ) ) {
DBGC ( iphdr->src, "IPv4 header too long at %zd bytes "
"(packet is %zd bytes)\n", hdrlen, iob_len ( iobuf ) );
goto err_header;
}
if ( ( csum = tcpip_chksum ( iphdr, hdrlen ) ) != 0 ) {
DBGC ( iphdr->src, "IPv4 checksum incorrect (is %04x "
"including checksum field, should be 0000)\n", csum );
goto err_header;
}
len = ntohs ( iphdr->len );
if ( len < hdrlen ) {
DBGC ( iphdr->src, "IPv4 length too short at %zd bytes "
"(header is %zd bytes)\n", len, hdrlen );
goto err_header;
}
if ( len > iob_len ( iobuf ) ) {
DBGC ( iphdr->src, "IPv4 length too long at %zd bytes "
"(packet is %zd bytes)\n", len, iob_len ( iobuf ) );
ipv4_stats.in_truncated_pkts++;
goto err_other;
}
/* Truncate packet to correct length */
iob_unput ( iobuf, ( iob_len ( iobuf ) - len ) );
/* Print IPv4 header for debugging */
DBGC2 ( iphdr->src, "IPv4 RX %s<-", inet_ntoa ( iphdr->dest ) );
DBGC2 ( iphdr->src, "%s len %d proto %d id %04x csum %04x\n",
inet_ntoa ( iphdr->src ), ntohs ( iphdr->len ), iphdr->protocol,
ntohs ( iphdr->ident ), ntohs ( iphdr->chksum ) );
/* Discard unicast packets not destined for us */
if ( ( ! ( flags & LL_MULTICAST ) ) &&
( iphdr->dest.s_addr != INADDR_BROADCAST ) &&
ipv4_has_any_addr ( netdev ) &&
( ! ipv4_has_addr ( netdev, iphdr->dest ) ) ) {
DBGC ( iphdr->src, "IPv4 discarding non-local unicast packet "
"for %s\n", inet_ntoa ( iphdr->dest ) );
ipv4_stats.in_addr_errors++;
goto err_other;
}
/* Perform fragment reassembly if applicable */
if ( iphdr->frags & htons ( IP_MASK_OFFSET | IP_MASK_MOREFRAGS ) ) {
/* Pass the fragment to fragment_reassemble() which returns
* either a fully reassembled I/O buffer or NULL.
*/
iobuf = fragment_reassemble ( &ipv4_reassembler, iobuf,
&hdrlen );
if ( ! iobuf )
return 0;
iphdr = iobuf->data;
}
/* Construct socket addresses, calculate pseudo-header
* checksum, and hand off to transport layer
*/
memset ( &src, 0, sizeof ( src ) );
src.sin.sin_family = AF_INET;
src.sin.sin_addr = iphdr->src;
memset ( &dest, 0, sizeof ( dest ) );
dest.sin.sin_family = AF_INET;
dest.sin.sin_addr = iphdr->dest;
pshdr_csum = ipv4_pshdr_chksum ( iobuf, TCPIP_EMPTY_CSUM );
iob_pull ( iobuf, hdrlen );
if ( ( rc = tcpip_rx ( iobuf, netdev, iphdr->protocol, &src.st,
&dest.st, pshdr_csum, &ipv4_stats ) ) != 0 ) {
DBGC ( src.sin.sin_addr, "IPv4 received packet rejected by "
"stack: %s\n", strerror ( rc ) );
return rc;
}
profile_stop ( &ipv4_rx_profiler );
return 0;
err_header:
ipv4_stats.in_hdr_errors++;
err_other:
free_iob ( iobuf );
return -EINVAL;
}
/**
* Check existence of IPv4 address for ARP
*
* @v netdev Network device
* @v net_addr Network-layer address
* @ret rc Return status code
*/
static int ipv4_arp_check ( struct net_device *netdev, const void *net_addr ) {
const struct in_addr *address = net_addr;
if ( ipv4_has_addr ( netdev, *address ) )
return 0;
return -ENOENT;
}
/**
* Parse IPv4 address
*
* @v string IPv4 address string
* @ret in IPv4 address to fill in
* @ret ok IPv4 address is valid
*
* Note that this function returns nonzero iff the address is valid,
* to match the standard BSD API function of the same name. Unlike
* most other iPXE functions, a zero therefore indicates failure.
*/
int inet_aton ( const char *string, struct in_addr *in ) {
const char *separator = "...";
uint8_t *byte = ( ( uint8_t * ) in );
char *endp;
unsigned long value;
while ( 1 ) {
value = strtoul ( string, &endp, 0 );
if ( string == endp )
return 0;
if ( value > 0xff )
return 0;
*(byte++) = value;
if ( *endp != *separator )
return 0;
if ( ! *(separator++) )
return 1;
string = ( endp + 1 );
}
}
/**
* Convert IPv4 address to dotted-quad notation
*
* @v in IPv4 address
* @ret string IPv4 address in dotted-quad notation
*/
char * inet_ntoa ( struct in_addr in ) {
static char buf[16]; /* "xxx.xxx.xxx.xxx" */
uint8_t *bytes = ( uint8_t * ) &in;
sprintf ( buf, "%d.%d.%d.%d", bytes[0], bytes[1], bytes[2], bytes[3] );
return buf;
}
/**
* Transcribe IPv4 address
*
* @v net_addr IPv4 address
* @ret string IPv4 address in dotted-quad notation
*
*/
static const char * ipv4_ntoa ( const void *net_addr ) {
return inet_ntoa ( * ( ( struct in_addr * ) net_addr ) );
}
/**
* Transcribe IPv4 socket address
*
* @v sa Socket address
* @ret string Socket address in standard notation
*/
static const char * ipv4_sock_ntoa ( struct sockaddr *sa ) {
struct sockaddr_in *sin = ( ( struct sockaddr_in * ) sa );
return inet_ntoa ( sin->sin_addr );
}
/**
* Parse IPv4 socket address
*
* @v string Socket address string
* @v sa Socket address to fill in
* @ret rc Return status code
*/
static int ipv4_sock_aton ( const char *string, struct sockaddr *sa ) {
struct sockaddr_in *sin = ( ( struct sockaddr_in * ) sa );
struct in_addr in;
if ( inet_aton ( string, &in ) ) {
sin->sin_addr = in;
return 0;
}
return -EINVAL;
}
/** IPv4 protocol */
struct net_protocol ipv4_protocol __net_protocol = {
.name = "IP",
.net_proto = htons ( ETH_P_IP ),
.net_addr_len = sizeof ( struct in_addr ),
.rx = ipv4_rx,
.ntoa = ipv4_ntoa,
};
/** IPv4 TCPIP net protocol */
struct tcpip_net_protocol ipv4_tcpip_protocol __tcpip_net_protocol = {
.name = "IPv4",
.sa_family = AF_INET,
.header_len = sizeof ( struct iphdr ),
.net_protocol = &ipv4_protocol,
.tx = ipv4_tx,
.netdev = ipv4_netdev,
};
/** IPv4 ARP protocol */
struct arp_net_protocol ipv4_arp_protocol __arp_net_protocol = {
.net_protocol = &ipv4_protocol,
.check = ipv4_arp_check,
};
/** IPv4 socket address converter */
struct sockaddr_converter ipv4_sockaddr_converter __sockaddr_converter = {
.family = AF_INET,
.ntoa = ipv4_sock_ntoa,
.aton = ipv4_sock_aton,
};
/******************************************************************************
*
* Settings
*
******************************************************************************
*/
/**
* Parse IPv4 address setting value
*
* @v type Setting type
* @v value Formatted setting value
* @v buf Buffer to contain raw value
* @v len Length of buffer
* @ret len Length of raw value, or negative error
*/
int parse_ipv4_setting ( const struct setting_type *type __unused,
const char *value, void *buf, size_t len ) {
struct in_addr ipv4;
/* Parse IPv4 address */
if ( inet_aton ( value, &ipv4 ) == 0 )
return -EINVAL;
/* Copy to buffer */
if ( len > sizeof ( ipv4 ) )
len = sizeof ( ipv4 );
memcpy ( buf, &ipv4, len );
return ( sizeof ( ipv4 ) );
}
/**
* Format IPv4 address setting value
*
* @v type Setting type
* @v raw Raw setting value
* @v raw_len Length of raw setting value
* @v buf Buffer to contain formatted value
* @v len Length of buffer
* @ret len Length of formatted value, or negative error
*/
int format_ipv4_setting ( const struct setting_type *type __unused,
const void *raw, size_t raw_len, char *buf,
size_t len ) {
const struct in_addr *ipv4 = raw;
if ( raw_len < sizeof ( *ipv4 ) )
return -EINVAL;
return snprintf ( buf, len, "%s", inet_ntoa ( *ipv4 ) );
}
/** IPv4 address setting */
const struct setting ip_setting __setting ( SETTING_IP4, ip ) = {
.name = "ip",
.description = "IP address",
.tag = DHCP_EB_YIADDR,
.type = &setting_type_ipv4,
};
/** IPv4 subnet mask setting */
const struct setting netmask_setting __setting ( SETTING_IP4, netmask ) = {
.name = "netmask",
.description = "Subnet mask",
.tag = DHCP_SUBNET_MASK,
.type = &setting_type_ipv4,
};
/** Default gateway setting */
const struct setting gateway_setting __setting ( SETTING_IP4, gateway ) = {
.name = "gateway",
.description = "Default gateway",
.tag = DHCP_ROUTERS,
.type = &setting_type_ipv4,
};
/**
* Send gratuitous ARP, if applicable
*
* @v netdev Network device
* @v address IPv4 address
* @v netmask Subnet mask
* @v gateway Gateway address (if any)
* @ret rc Return status code
*/
static int ipv4_gratuitous_arp ( struct net_device *netdev,
struct in_addr address,
struct in_addr netmask __unused,
struct in_addr gateway __unused ) {
int rc;
/* Do nothing if network device already has this IPv4 address */
if ( ipv4_has_addr ( netdev, address ) )
return 0;
/* Transmit gratuitous ARP */
DBGC ( netdev, "IPv4 sending gratuitous ARP for %s via %s\n",
inet_ntoa ( address ), netdev->name );
if ( ( rc = arp_tx_request ( netdev, &ipv4_protocol, &address,
&address ) ) != 0 ) {
DBGC ( netdev, "IPv4 could not transmit gratuitous ARP: %s\n",
strerror ( rc ) );
/* Treat failures as non-fatal */
}
return 0;
}
/**
* Process IPv4 network device settings
*
* @v apply Application method
* @ret rc Return status code
*/
static int ipv4_settings ( int ( * apply ) ( struct net_device *netdev,
struct in_addr address,
struct in_addr netmask,
struct in_addr gateway ) ) {
struct net_device *netdev;
struct settings *settings;
struct in_addr address = { 0 };
struct in_addr netmask = { 0 };
struct in_addr gateway = { 0 };
int rc;
/* Process settings for each network device */
for_each_netdev ( netdev ) {
/* Get network device settings */
settings = netdev_settings ( netdev );
/* Get IPv4 address */
address.s_addr = 0;
fetch_ipv4_setting ( settings, &ip_setting, &address );
if ( ! address.s_addr )
continue;
/* Get subnet mask */
fetch_ipv4_setting ( settings, &netmask_setting, &netmask );
/* Calculate default netmask, if necessary */
if ( ! netmask.s_addr ) {
if ( IN_IS_CLASSA ( address.s_addr ) ) {
netmask.s_addr = INADDR_NET_CLASSA;
} else if ( IN_IS_CLASSB ( address.s_addr ) ) {
netmask.s_addr = INADDR_NET_CLASSB;
} else if ( IN_IS_CLASSC ( address.s_addr ) ) {
netmask.s_addr = INADDR_NET_CLASSC;
}
}
/* Get default gateway, if present */
fetch_ipv4_setting ( settings, &gateway_setting, &gateway );
/* Apply settings */
if ( ( rc = apply ( netdev, address, netmask, gateway ) ) != 0 )
return rc;
}
return 0;
}
/**
* Create IPv4 routing table based on configured settings
*
* @ret rc Return status code
*/
static int ipv4_create_routes ( void ) {
struct ipv4_miniroute *miniroute;
struct ipv4_miniroute *tmp;
int rc;
/* Send gratuitous ARPs for any new IPv4 addresses */
ipv4_settings ( ipv4_gratuitous_arp );
/* Delete all existing routes */
list_for_each_entry_safe ( miniroute, tmp, &ipv4_miniroutes, list )
del_ipv4_miniroute ( miniroute );
/* Create a route for each configured network device */
if ( ( rc = ipv4_settings ( add_ipv4_miniroute ) ) != 0 )
return rc;
return 0;
}
/** IPv4 settings applicator */
struct settings_applicator ipv4_settings_applicator __settings_applicator = {
.apply = ipv4_create_routes,
};
/* Drag in objects via ipv4_protocol */
REQUIRING_SYMBOL ( ipv4_protocol );
/* Drag in ICMPv4 */
REQUIRE_OBJECT ( icmpv4 );
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