iPXE
Data Structures | Macros | Functions | Variables
cachedhcp.c File Reference

Cached DHCP packet. More...

#include <stdint.h>
#include <stdlib.h>
#include <errno.h>
#include <ipxe/dhcppkt.h>
#include <ipxe/init.h>
#include <ipxe/netdevice.h>
#include <ipxe/vlan.h>
#include <ipxe/cachedhcp.h>

Go to the source code of this file.

Data Structures

struct  cached_dhcp_packet
 A cached DHCP packet. More...
 

Macros

#define colour   &cached_dhcpack
 Colour for debug messages. More...
 

Functions

 FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
 
static void cachedhcp_free (struct cached_dhcp_packet *cache)
 Free cached DHCP packet. More...
 
static int cachedhcp_apply (struct cached_dhcp_packet *cache, struct net_device *netdev)
 Apply cached DHCP packet settings. More...
 
int cachedhcp_record (struct cached_dhcp_packet *cache, unsigned int vlan, userptr_t data, size_t max_len)
 Record cached DHCP packet. More...
 
static void cachedhcp_startup (void)
 Cached DHCP packet startup function. More...
 
static void cachedhcp_shutdown (int booting __unused)
 Cached DHCP packet shutdown function. More...
 
struct startup_fn cachedhcp_startup_fn __startup_fn (STARTUP_LATE)
 Cached DHCPACK startup function. More...
 
static int cachedhcp_probe (struct net_device *netdev, void *priv __unused)
 Apply cached DHCPACK to network device, if applicable. More...
 

Variables

struct cached_dhcp_packet cached_dhcpack
 Cached DHCPACK. More...
 
struct cached_dhcp_packet cached_proxydhcp
 Cached ProxyDHCPOFFER. More...
 
struct cached_dhcp_packet cached_pxebs
 Cached PXEBSACK. More...
 
static struct cached_dhcp_packetcached_packets []
 List of cached DHCP packets. More...
 
struct net_driver cachedhcp_driver __net_driver
 Cached DHCP packet network device driver. More...
 

Detailed Description

Cached DHCP packet.

Definition in file cachedhcp.c.

Macro Definition Documentation

◆ colour

#define colour   &cached_dhcpack

Colour for debug messages.

Definition at line 74 of file cachedhcp.c.

Function Documentation

◆ FILE_LICENCE()

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL  )

◆ cachedhcp_free()

static void cachedhcp_free ( struct cached_dhcp_packet cache)
static

Free cached DHCP packet.

Parameters
cacheCached DHCP packet

Definition at line 81 of file cachedhcp.c.

81  {
82 
83  dhcppkt_put ( cache->dhcppkt );
84  cache->dhcppkt = NULL;
85 }
struct dhcp_packet * dhcppkt
DHCP packet (if any)
Definition: cachedhcp.c:46
static void dhcppkt_put(struct dhcp_packet *dhcppkt)
Decrement reference count on DHCP packet.
Definition: dhcppkt.h:49
#define NULL
NULL pointer (VOID *)
Definition: Base.h:321

References cached_dhcp_packet::dhcppkt, dhcppkt_put(), and NULL.

Referenced by cachedhcp_apply(), cachedhcp_record(), cachedhcp_shutdown(), and cachedhcp_startup().

◆ cachedhcp_apply()

static int cachedhcp_apply ( struct cached_dhcp_packet cache,
struct net_device netdev 
)
static

Apply cached DHCP packet settings.

Parameters
cacheCached DHCP packet
netdevNetwork device, or NULL
Return values
rcReturn status code

Definition at line 94 of file cachedhcp.c.

95  {
96  struct settings *settings = NULL;
97  struct ll_protocol *ll_protocol;
98  const uint8_t *chaddr;
99  uint8_t *hw_addr;
100  uint8_t *ll_addr;
101  size_t ll_addr_len;
102  int rc;
103 
104  /* Do nothing if cache is empty */
105  if ( ! cache->dhcppkt )
106  return 0;
107  chaddr = cache->dhcppkt->dhcphdr->chaddr;
108 
109  /* Handle association with network device, if specified */
110  if ( netdev ) {
111  hw_addr = netdev->hw_addr;
112  ll_addr = netdev->ll_addr;
115 
116  /* If cached packet's MAC address matches the network
117  * device's permanent MAC address, then assume that
118  * the permanent MAC address ought to be the network
119  * device's current link-layer address.
120  *
121  * This situation can arise when the PXE ROM does not
122  * understand the system-specific mechanism for
123  * overriding the MAC address, and so uses the
124  * permanent MAC address instead. We choose to match
125  * this behaviour in order to minimise surprise.
126  */
127  if ( memcmp ( hw_addr, chaddr, ll_addr_len ) == 0 ) {
128  if ( memcmp ( hw_addr, ll_addr, ll_addr_len ) != 0 ) {
129  DBGC ( colour, "CACHEDHCP %s resetting %s MAC "
130  "%s ", cache->name, netdev->name,
131  ll_protocol->ntoa ( ll_addr ) );
132  DBGC ( colour, "-> %s\n",
133  ll_protocol->ntoa ( hw_addr ) );
134  }
135  memcpy ( ll_addr, hw_addr, ll_addr_len );
136  }
137 
138  /* Do nothing unless cached packet's MAC address
139  * matches this network device.
140  */
141  if ( memcmp ( ll_addr, chaddr, ll_addr_len ) != 0 ) {
142  DBGC ( colour, "CACHEDHCP %s %s does not match %s\n",
143  cache->name, ll_protocol->ntoa ( chaddr ),
144  netdev->name );
145  return 0;
146  }
147 
148  /* Do nothing unless cached packet's VLAN tag matches
149  * this network device.
150  */
151  if ( vlan_tag ( netdev ) != cache->vlan ) {
152  DBGC ( colour, "CACHEDHCP %s VLAN %d does not match "
153  "%s\n", cache->name, cache->vlan,
154  netdev->name );
155  return 0;
156  }
157 
158  /* Use network device's settings block */
160  DBGC ( colour, "CACHEDHCP %s is for %s\n",
161  cache->name, netdev->name );
162  }
163 
164  /* Register settings */
165  if ( ( rc = register_settings ( &cache->dhcppkt->settings, settings,
166  cache->name ) ) != 0 ) {
167  DBGC ( colour, "CACHEDHCP %s could not register settings: %s\n",
168  cache->name, strerror ( rc ) );
169  return rc;
170  }
171 
172  /* Free cached DHCP packet */
173  cachedhcp_free ( cache );
174 
175  return 0;
176 }
#define colour
Colour for debug messages.
Definition: cachedhcp.c:74
struct arbelprm_rc_send_wqe rc
Definition: arbel.h:14
uint8_t ll_addr_len
Link-layer address length.
Definition: netdevice.h:198
unsigned int vlan
VLAN tag (if applicable)
Definition: cachedhcp.c:48
#define DBGC(...)
Definition: compiler.h:505
static struct settings * netdev_settings(struct net_device *netdev)
Get per-netdevice configuration settings block.
Definition: netdevice.h:583
A link-layer protocol.
Definition: netdevice.h:114
struct dhcp_packet * dhcppkt
DHCP packet (if any)
Definition: cachedhcp.c:46
static void cachedhcp_free(struct cached_dhcp_packet *cache)
Free cached DHCP packet.
Definition: cachedhcp.c:81
void * memcpy(void *dest, const void *src, size_t len) __nonnull
static struct net_device * netdev
Definition: gdbudp.c:52
char * strerror(int errno)
Retrieve string representation of error number.
Definition: strerror.c:78
uint8_t chaddr[16]
Client hardware address.
Definition: dhcp.h:659
A settings block.
Definition: settings.h:132
unsigned char uint8_t
Definition: stdint.h:10
struct settings settings
Settings interface.
Definition: dhcppkt.h:28
char name[NETDEV_NAME_LEN]
Name of this network device.
Definition: netdevice.h:362
struct dhcphdr * dhcphdr
The DHCP packet contents.
Definition: dhcppkt.h:24
const char * name
Settings block name.
Definition: cachedhcp.c:44
const char *(* ntoa)(const void *ll_addr)
Transcribe link-layer address.
Definition: netdevice.h:163
int register_settings(struct settings *settings, struct settings *parent, const char *name)
Register settings block.
Definition: settings.c:475
uint8_t ll_addr[MAX_LL_ADDR_LEN]
Link-layer address.
Definition: netdevice.h:387
static unsigned int vlan_tag(struct net_device *netdev)
Get the VLAN tag.
Definition: vlan.h:73
int memcmp(const void *first, const void *second, size_t len)
Compare memory regions.
Definition: string.c:114
uint8_t hw_addr[MAX_HW_ADDR_LEN]
Hardware address.
Definition: netdevice.h:381
#define NULL
NULL pointer (VOID *)
Definition: Base.h:321
struct ll_protocol * ll_protocol
Link-layer protocol.
Definition: netdevice.h:372

References cachedhcp_free(), dhcphdr::chaddr, colour, DBGC, dhcp_packet::dhcphdr, cached_dhcp_packet::dhcppkt, net_device::hw_addr, net_device::ll_addr, ll_protocol::ll_addr_len, net_device::ll_protocol, memcmp(), memcpy(), cached_dhcp_packet::name, net_device::name, netdev, netdev_settings(), ll_protocol::ntoa, NULL, rc, register_settings(), dhcp_packet::settings, strerror(), cached_dhcp_packet::vlan, and vlan_tag().

Referenced by cachedhcp_probe(), and cachedhcp_startup().

◆ cachedhcp_record()

int cachedhcp_record ( struct cached_dhcp_packet cache,
unsigned int  vlan,
userptr_t  data,
size_t  max_len 
)

Record cached DHCP packet.

Parameters
cacheCached DHCP packet
vlanVLAN tag, if any
dataDHCPACK packet buffer
max_lenMaximum possible length
Return values
rcReturn status code

Definition at line 187 of file cachedhcp.c.

188  {
189  struct dhcp_packet *dhcppkt;
190  struct dhcp_packet *tmp;
191  struct dhcphdr *dhcphdr;
192  unsigned int i;
193  size_t len;
194 
195  /* Free any existing cached packet */
196  cachedhcp_free ( cache );
197 
198  /* Allocate and populate DHCP packet */
199  dhcppkt = zalloc ( sizeof ( *dhcppkt ) + max_len );
200  if ( ! dhcppkt ) {
201  DBGC ( colour, "CACHEDHCP %s could not allocate copy\n",
202  cache->name );
203  return -ENOMEM;
204  }
205  dhcphdr = ( ( ( void * ) dhcppkt ) + sizeof ( *dhcppkt ) );
207  dhcppkt_init ( dhcppkt, dhcphdr, max_len );
208 
209  /* Shrink packet to required length. If reallocation fails,
210  * just continue to use the original packet and waste the
211  * unused space.
212  */
213  len = dhcppkt_len ( dhcppkt );
214  assert ( len <= max_len );
215  tmp = realloc ( dhcppkt, ( sizeof ( *dhcppkt ) + len ) );
216  if ( tmp )
217  dhcppkt = tmp;
218 
219  /* Reinitialise packet at new address */
220  dhcphdr = ( ( ( void * ) dhcppkt ) + sizeof ( *dhcppkt ) );
221  dhcppkt_init ( dhcppkt, dhcphdr, len );
222 
223  /* Discard duplicate packets, since some PXE stacks (including
224  * iPXE itself) will report the DHCPACK packet as the PXEBSACK
225  * if no separate PXEBSACK exists.
226  */
227  for ( i = 0 ; i < ( sizeof ( cached_packets ) /
228  sizeof ( cached_packets[0] ) ) ; i++ ) {
229  tmp = cached_packets[i]->dhcppkt;
230  if ( tmp && ( dhcppkt_len ( tmp ) == len ) &&
231  ( memcmp ( tmp->dhcphdr, dhcppkt->dhcphdr, len ) == 0 ) ) {
232  DBGC ( colour, "CACHEDHCP %s duplicates %s\n",
233  cache->name, cached_packets[i]->name );
234  dhcppkt_put ( dhcppkt );
235  return -EEXIST;
236  }
237  }
238 
239  /* Store as cached packet */
240  DBGC ( colour, "CACHEDHCP %s at %#08lx+%#zx/%#zx\n", cache->name,
241  user_to_phys ( data, 0 ), len, max_len );
242  cache->dhcppkt = dhcppkt;
243  cache->vlan = vlan;
244 
245  return 0;
246 }
#define colour
Colour for debug messages.
Definition: cachedhcp.c:74
A DHCP packet.
Definition: dhcppkt.h:20
unsigned int vlan
VLAN tag (if applicable)
Definition: cachedhcp.c:48
#define EEXIST
File exists.
Definition: errno.h:388
uint16_t max_len
Maximum length (in bytes)
Definition: ntlm.h:18
static __always_inline void copy_from_user(void *dest, userptr_t src, off_t src_off, size_t len)
Copy data from user buffer.
Definition: uaccess.h:337
unsigned long user_to_phys(userptr_t userptr, off_t offset)
Convert user pointer to physical address.
#define DBGC(...)
Definition: compiler.h:505
static struct cached_dhcp_packet * cached_packets[]
List of cached DHCP packets.
Definition: cachedhcp.c:67
struct dhcp_packet * dhcppkt
DHCP packet (if any)
Definition: cachedhcp.c:46
static void cachedhcp_free(struct cached_dhcp_packet *cache)
Free cached DHCP packet.
Definition: cachedhcp.c:81
unsigned long tmp
Definition: linux_pci.h:53
#define ENOMEM
Not enough space.
Definition: errno.h:534
assert((readw(&hdr->flags) &(GTF_reading|GTF_writing))==0)
void * zalloc(size_t size)
Allocate cleared memory.
Definition: malloc.c:624
A DHCP header.
Definition: dhcp.h:613
void dhcppkt_init(struct dhcp_packet *dhcppkt, struct dhcphdr *data, size_t len)
Initialise DHCP packet.
Definition: dhcppkt.c:300
struct dhcphdr * dhcphdr
The DHCP packet contents.
Definition: dhcppkt.h:24
uint32_t len
Length.
Definition: ena.h:14
static void dhcppkt_put(struct dhcp_packet *dhcppkt)
Decrement reference count on DHCP packet.
Definition: dhcppkt.h:49
static size_t dhcppkt_len(struct dhcp_packet *dhcppkt)
Get used length of DHCP packet.
Definition: dhcppkt.h:59
const char * name
Settings block name.
Definition: cachedhcp.c:44
uint8_t data[48]
Additional event data.
Definition: ena.h:22
void * realloc(void *old_ptr, size_t new_size)
Reallocate memory.
Definition: malloc.c:521
int memcmp(const void *first, const void *second, size_t len)
Compare memory regions.
Definition: string.c:114

References assert(), cached_packets, cachedhcp_free(), colour, copy_from_user(), data, DBGC, dhcp_packet::dhcphdr, cached_dhcp_packet::dhcppkt, dhcppkt_init(), dhcppkt_len(), dhcppkt_put(), EEXIST, ENOMEM, len, max_len, memcmp(), cached_dhcp_packet::name, realloc(), tmp, user_to_phys(), cached_dhcp_packet::vlan, and zalloc().

Referenced by cachedhcp_init(), and efi_cachedhcp_record().

◆ cachedhcp_startup()

static void cachedhcp_startup ( void  )
static

Cached DHCP packet startup function.

Definition at line 252 of file cachedhcp.c.

252  {
253 
254  /* Apply cached ProxyDHCPOFFER, if any */
257 
258  /* Apply cached PXEBSACK, if any */
261 
262  /* Report unclaimed DHCPACK, if any. Do not free yet, since
263  * it may still be claimed by a dynamically created device
264  * such as a VLAN device.
265  */
266  if ( cached_dhcpack.dhcppkt ) {
267  DBGC ( colour, "CACHEDHCP %s unclaimed\n",
269  }
270 }
#define colour
Colour for debug messages.
Definition: cachedhcp.c:74
struct cached_dhcp_packet cached_proxydhcp
Cached ProxyDHCPOFFER.
Definition: cachedhcp.c:57
#define DBGC(...)
Definition: compiler.h:505
struct dhcp_packet * dhcppkt
DHCP packet (if any)
Definition: cachedhcp.c:46
static void cachedhcp_free(struct cached_dhcp_packet *cache)
Free cached DHCP packet.
Definition: cachedhcp.c:81
static int cachedhcp_apply(struct cached_dhcp_packet *cache, struct net_device *netdev)
Apply cached DHCP packet settings.
Definition: cachedhcp.c:94
struct cached_dhcp_packet cached_dhcpack
Cached DHCPACK.
Definition: cachedhcp.c:52
const char * name
Settings block name.
Definition: cachedhcp.c:44
struct cached_dhcp_packet cached_pxebs
Cached PXEBSACK.
Definition: cachedhcp.c:62
#define NULL
NULL pointer (VOID *)
Definition: Base.h:321

References cached_dhcpack, cached_proxydhcp, cached_pxebs, cachedhcp_apply(), cachedhcp_free(), colour, DBGC, cached_dhcp_packet::dhcppkt, cached_dhcp_packet::name, and NULL.

◆ cachedhcp_shutdown()

static void cachedhcp_shutdown ( int booting  __unused)
static

Cached DHCP packet shutdown function.

Parameters
bootingSystem is shutting down for OS boot

Definition at line 277 of file cachedhcp.c.

277  {
278 
279  /* Free cached DHCPACK, if any */
280  if ( cached_dhcpack.dhcppkt ) {
281  DBGC ( colour, "CACHEDHCP %s never claimed\n",
283  }
285 }
#define colour
Colour for debug messages.
Definition: cachedhcp.c:74
#define DBGC(...)
Definition: compiler.h:505
struct dhcp_packet * dhcppkt
DHCP packet (if any)
Definition: cachedhcp.c:46
static void cachedhcp_free(struct cached_dhcp_packet *cache)
Free cached DHCP packet.
Definition: cachedhcp.c:81
struct cached_dhcp_packet cached_dhcpack
Cached DHCPACK.
Definition: cachedhcp.c:52
const char * name
Settings block name.
Definition: cachedhcp.c:44

References cached_dhcpack, cachedhcp_free(), colour, DBGC, cached_dhcp_packet::dhcppkt, and cached_dhcp_packet::name.

◆ __startup_fn()

struct startup_fn cachedhcp_startup_fn __startup_fn ( STARTUP_LATE  )

Cached DHCPACK startup function.

◆ cachedhcp_probe()

static int cachedhcp_probe ( struct net_device netdev,
void *priv  __unused 
)
static

Apply cached DHCPACK to network device, if applicable.

Parameters
netdevNetwork device
privPrivate data
Return values
rcReturn status code

Definition at line 301 of file cachedhcp.c.

301  {
302 
303  /* Apply cached DHCPACK to network device, if applicable */
305 }
static int cachedhcp_apply(struct cached_dhcp_packet *cache, struct net_device *netdev)
Apply cached DHCP packet settings.
Definition: cachedhcp.c:94
static struct net_device * netdev
Definition: gdbudp.c:52
struct cached_dhcp_packet cached_dhcpack
Cached DHCPACK.
Definition: cachedhcp.c:52

References cached_dhcpack, cachedhcp_apply(), and netdev.

Variable Documentation

◆ cached_dhcpack

struct cached_dhcp_packet cached_dhcpack
Initial value:
= {
}
#define DHCP_SETTINGS_NAME
Settings block name used for DHCP responses.
Definition: dhcp.h:708

Cached DHCPACK.

Definition at line 52 of file cachedhcp.c.

Referenced by cachedhcp_init(), cachedhcp_probe(), cachedhcp_shutdown(), cachedhcp_startup(), and efi_cachedhcp_record().

◆ cached_proxydhcp

struct cached_dhcp_packet cached_proxydhcp
Initial value:
= {
}
#define PROXYDHCP_SETTINGS_NAME
Settings block name used for ProxyDHCP responses.
Definition: dhcp.h:711

Cached ProxyDHCPOFFER.

Definition at line 57 of file cachedhcp.c.

Referenced by cachedhcp_startup(), and efi_cachedhcp_record().

◆ cached_pxebs

struct cached_dhcp_packet cached_pxebs
Initial value:
= {
}
#define PXEBS_SETTINGS_NAME
Setting block name used for BootServerDHCP responses.
Definition: dhcp.h:714

Cached PXEBSACK.

Definition at line 62 of file cachedhcp.c.

Referenced by cachedhcp_startup(), and efi_cachedhcp_record().

◆ cached_packets

struct cached_dhcp_packet* cached_packets[]
static
Initial value:
= {
}
struct cached_dhcp_packet cached_proxydhcp
Cached ProxyDHCPOFFER.
Definition: cachedhcp.c:57
struct cached_dhcp_packet cached_dhcpack
Cached DHCPACK.
Definition: cachedhcp.c:52
struct cached_dhcp_packet cached_pxebs
Cached PXEBSACK.
Definition: cachedhcp.c:62

List of cached DHCP packets.

Definition at line 67 of file cachedhcp.c.

Referenced by cachedhcp_record().

◆ __net_driver

struct net_driver cachedhcp_driver __net_driver
Initial value:
= {
.name = "cachedhcp",
.probe = cachedhcp_probe,
}
static int cachedhcp_probe(struct net_device *netdev, void *priv __unused)
Apply cached DHCPACK to network device, if applicable.
Definition: cachedhcp.c:301

Cached DHCP packet network device driver.

Definition at line 308 of file cachedhcp.c.