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/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, userptr_t data, size_t max_len)
 Record cached DHCP packet. More...
 
static void cachedhcp_startup (void)
 Cached DHCPACK startup 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)
 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 71 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 78 of file cachedhcp.c.

78  {
79 
80  dhcppkt_put ( cache->dhcppkt );
81  cache->dhcppkt = NULL;
82 }
struct dhcp_packet * dhcppkt
DHCP packet (if any)
Definition: cachedhcp.c:45
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:362

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

Referenced by cachedhcp_apply(), cachedhcp_record(), 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 91 of file cachedhcp.c.

92  {
93  struct settings *settings = NULL;
94  struct ll_protocol *ll_protocol;
95  const uint8_t *chaddr;
96  uint8_t *hw_addr;
97  uint8_t *ll_addr;
98  size_t ll_addr_len;
99  int rc;
100 
101  /* Do nothing if cache is empty */
102  if ( ! cache->dhcppkt )
103  return 0;
104  chaddr = cache->dhcppkt->dhcphdr->chaddr;
105 
106  /* Handle association with network device, if specified */
107  if ( netdev ) {
108  hw_addr = netdev->hw_addr;
109  ll_addr = netdev->ll_addr;
112 
113  /* If cached packet's MAC address matches the network
114  * device's permanent MAC address, then assume that
115  * the permanent MAC address ought to be the network
116  * device's current link-layer address.
117  *
118  * This situation can arise when the PXE ROM does not
119  * understand the system-specific mechanism for
120  * overriding the MAC address, and so uses the
121  * permanent MAC address instead. We choose to match
122  * this behaviour in order to minimise surprise.
123  */
124  if ( memcmp ( hw_addr, chaddr, ll_addr_len ) == 0 ) {
125  if ( memcmp ( hw_addr, ll_addr, ll_addr_len ) != 0 ) {
126  DBGC ( colour, "CACHEDHCP %s resetting %s MAC "
127  "%s ", cache->name, netdev->name,
128  ll_protocol->ntoa ( ll_addr ) );
129  DBGC ( colour, "-> %s\n",
130  ll_protocol->ntoa ( hw_addr ) );
131  }
132  memcpy ( ll_addr, hw_addr, ll_addr_len );
133  }
134 
135  /* Do nothing unless cached packet's MAC address
136  * matches this network device.
137  */
138  if ( memcmp ( ll_addr, chaddr, ll_addr_len ) != 0 ) {
139  DBGC ( colour, "CACHEDHCP %s does not match %s\n",
140  cache->name, netdev->name );
141  return 0;
142  }
143  DBGC ( colour, "CACHEDHCP %s is for %s\n",
144  cache->name, netdev->name );
145 
146  /* Use network device's settings block */
148  }
149 
150  /* Register settings */
151  if ( ( rc = register_settings ( &cache->dhcppkt->settings, settings,
152  cache->name ) ) != 0 ) {
153  DBGC ( colour, "CACHEDHCP %s could not register settings: %s\n",
154  cache->name, strerror ( rc ) );
155  return rc;
156  }
157 
158  /* Free cached DHCP packet */
159  cachedhcp_free ( cache );
160 
161  return 0;
162 }
#define colour
Colour for debug messages.
Definition: cachedhcp.c:71
struct arbelprm_rc_send_wqe rc
Definition: arbel.h:14
uint8_t ll_addr_len
Link-layer address length.
Definition: netdevice.h:198
#define DBGC(...)
Definition: compiler.h:505
static struct settings * netdev_settings(struct net_device *netdev)
Get per-netdevice configuration settings block.
Definition: netdevice.h:589
A link-layer protocol.
Definition: netdevice.h:114
struct dhcp_packet * dhcppkt
DHCP packet (if any)
Definition: cachedhcp.c:45
static void cachedhcp_free(struct cached_dhcp_packet *cache)
Free cached DHCP packet.
Definition: cachedhcp.c:78
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:637
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:43
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
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:362
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, and strerror().

Referenced by cachedhcp_probe(), and cachedhcp_startup().

◆ cachedhcp_record()

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

Record cached DHCP packet.

Parameters
cacheCached DHCP packet
dataDHCPACK packet buffer
max_lenMaximum possible length
Return values
rcReturn status code

Definition at line 172 of file cachedhcp.c.

173  {
174  struct dhcp_packet *dhcppkt;
175  struct dhcp_packet *tmp;
176  struct dhcphdr *dhcphdr;
177  unsigned int i;
178  size_t len;
179 
180  /* Free any existing cached packet */
181  cachedhcp_free ( cache );
182 
183  /* Allocate and populate DHCP packet */
184  dhcppkt = zalloc ( sizeof ( *dhcppkt ) + max_len );
185  if ( ! dhcppkt ) {
186  DBGC ( colour, "CACHEDHCP %s could not allocate copy\n",
187  cache->name );
188  return -ENOMEM;
189  }
190  dhcphdr = ( ( ( void * ) dhcppkt ) + sizeof ( *dhcppkt ) );
192  dhcppkt_init ( dhcppkt, dhcphdr, max_len );
193 
194  /* Shrink packet to required length. If reallocation fails,
195  * just continue to use the original packet and waste the
196  * unused space.
197  */
198  len = dhcppkt_len ( dhcppkt );
199  assert ( len <= max_len );
200  tmp = realloc ( dhcppkt, ( sizeof ( *dhcppkt ) + len ) );
201  if ( tmp )
202  dhcppkt = tmp;
203 
204  /* Reinitialise packet at new address */
205  dhcphdr = ( ( ( void * ) dhcppkt ) + sizeof ( *dhcppkt ) );
206  dhcppkt_init ( dhcppkt, dhcphdr, len );
207 
208  /* Discard duplicate packets, since some PXE stacks (including
209  * iPXE itself) will report the DHCPACK packet as the PXEBSACK
210  * if no separate PXEBSACK exists.
211  */
212  for ( i = 0 ; i < ( sizeof ( cached_packets ) /
213  sizeof ( cached_packets[0] ) ) ; i++ ) {
214  tmp = cached_packets[i]->dhcppkt;
215  if ( tmp && ( dhcppkt_len ( tmp ) == len ) &&
216  ( memcmp ( tmp->dhcphdr, dhcppkt->dhcphdr, len ) == 0 ) ) {
217  DBGC ( colour, "CACHEDHCP %s duplicates %s\n",
218  cache->name, cached_packets[i]->name );
219  dhcppkt_put ( dhcppkt );
220  return -EEXIST;
221  }
222  }
223 
224  /* Store as cached packet */
225  DBGC ( colour, "CACHEDHCP %s at %#08lx+%#zx/%#zx\n", cache->name,
226  user_to_phys ( data, 0 ), len, max_len );
227  cache->dhcppkt = dhcppkt;
228 
229  return 0;
230 }
#define colour
Colour for debug messages.
Definition: cachedhcp.c:71
A DHCP packet.
Definition: dhcppkt.h:20
static void size_t size_t max_len
Definition: entropy.h:153
#define EEXIST
File exists.
Definition: errno.h:388
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:64
struct dhcp_packet * dhcppkt
DHCP packet (if any)
Definition: cachedhcp.c:45
static void cachedhcp_free(struct cached_dhcp_packet *cache)
Free cached DHCP packet.
Definition: cachedhcp.c:78
#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
uint8_t * tmp
Definition: entropy.h:156
A DHCP header.
Definition: dhcp.h:591
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:43
void * realloc(void *old_ptr, size_t new_size)
Reallocate memory.
Definition: malloc.c:521
struct arbelprm_port_state_change_st data
Message.
Definition: arbel.h:12
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(), and zalloc().

Referenced by cachedhcp_init(), and efi_cachedhcp_record().

◆ cachedhcp_startup()

static void cachedhcp_startup ( void  )
static

Cached DHCPACK startup function.

Definition at line 236 of file cachedhcp.c.

236  {
237 
238  /* Apply cached ProxyDHCPOFFER, if any */
240 
241  /* Apply cached PXEBSACK, if any */
243 
244  /* Free any remaining cached packets */
245  if ( cached_dhcpack.dhcppkt ) {
246  DBGC ( colour, "CACHEDHCP %s unclaimed\n",
248  }
252 }
#define colour
Colour for debug messages.
Definition: cachedhcp.c:71
struct cached_dhcp_packet cached_proxydhcp
Cached ProxyDHCPOFFER.
Definition: cachedhcp.c:54
#define DBGC(...)
Definition: compiler.h:505
struct dhcp_packet * dhcppkt
DHCP packet (if any)
Definition: cachedhcp.c:45
static void cachedhcp_free(struct cached_dhcp_packet *cache)
Free cached DHCP packet.
Definition: cachedhcp.c:78
static int cachedhcp_apply(struct cached_dhcp_packet *cache, struct net_device *netdev)
Apply cached DHCP packet settings.
Definition: cachedhcp.c:91
struct cached_dhcp_packet cached_dhcpack
Cached DHCPACK.
Definition: cachedhcp.c:49
const char * name
Settings block name.
Definition: cachedhcp.c:43
struct cached_dhcp_packet cached_pxebs
Cached PXEBSACK.
Definition: cachedhcp.c:59
#define NULL
NULL pointer (VOID *)
Definition: Base.h:362

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

◆ __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)
static

Apply cached DHCPACK to network device, if applicable.

Parameters
netdevNetwork device
Return values
rcReturn status code

Definition at line 266 of file cachedhcp.c.

266  {
267 
268  /* Apply cached DHCPACK to network device, if applicable */
270 }
static int cachedhcp_apply(struct cached_dhcp_packet *cache, struct net_device *netdev)
Apply cached DHCP packet settings.
Definition: cachedhcp.c:91
static struct net_device * netdev
Definition: gdbudp.c:52
struct cached_dhcp_packet cached_dhcpack
Cached DHCPACK.
Definition: cachedhcp.c:49

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:686

Cached DHCPACK.

Definition at line 49 of file cachedhcp.c.

Referenced by cachedhcp_init(), cachedhcp_probe(), 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:689

Cached ProxyDHCPOFFER.

Definition at line 54 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:692

Cached PXEBSACK.

Definition at line 59 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:54
struct cached_dhcp_packet cached_dhcpack
Cached DHCPACK.
Definition: cachedhcp.c:49
struct cached_dhcp_packet cached_pxebs
Cached PXEBSACK.
Definition: cachedhcp.c:59

List of cached DHCP packets.

Definition at line 64 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)
Apply cached DHCPACK to network device, if applicable.
Definition: cachedhcp.c:266

Cached DHCP packet network device driver.

Definition at line 273 of file cachedhcp.c.