iPXE
ntp.c
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1 /*
2  * Copyright (C) 2016 Michael Brown <mbrown@fensystems.co.uk>.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 of the
7  * License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17  * 02110-1301, USA.
18  *
19  * You can also choose to distribute this program under the terms of
20  * the Unmodified Binary Distribution Licence (as given in the file
21  * COPYING.UBDL), provided that you have satisfied its requirements.
22  */
23 
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25 
26 #include <stdint.h>
27 #include <string.h>
28 #include <errno.h>
29 #include <time.h>
30 #include <ipxe/malloc.h>
31 #include <ipxe/refcnt.h>
32 #include <ipxe/iobuf.h>
33 #include <ipxe/xfer.h>
34 #include <ipxe/open.h>
35 #include <ipxe/retry.h>
36 #include <ipxe/timer.h>
37 #include <ipxe/time.h>
38 #include <ipxe/tcpip.h>
39 #include <ipxe/ntp.h>
40 
41 /** @file
42  *
43  * Network Time Protocol
44  *
45  */
46 
47 /** An NTP client */
48 struct ntp_client {
49  /** Reference count */
50  struct refcnt refcnt;
51  /** Job control interface */
52  struct interface job;
53  /** Data transfer interface */
54  struct interface xfer;
55  /** Retransmission timer */
57 };
58 
59 /**
60  * Close NTP client
61  *
62  * @v ntp NTP client
63  * @v rc Reason for close
64  */
65 static void ntp_close ( struct ntp_client *ntp, int rc ) {
66 
67  /* Stop timer */
68  stop_timer ( &ntp->timer );
69 
70  /* Shut down interfaces */
71  intf_shutdown ( &ntp->xfer, rc );
72  intf_shutdown ( &ntp->job, rc );
73 }
74 
75 /**
76  * Send NTP request
77  *
78  * @v ntp NTP client
79  * @ret rc Return status code
80  */
81 static int ntp_request ( struct ntp_client *ntp ) {
82  struct ntp_header hdr;
83  int rc;
84 
85  DBGC ( ntp, "NTP %p sending request\n", ntp );
86 
87  /* Construct header */
88  memset ( &hdr, 0, sizeof ( hdr ) );
90  hdr.transmit.seconds = htonl ( time ( NULL ) + NTP_EPOCH );
91  hdr.transmit.fraction = htonl ( NTP_FRACTION_MAGIC );
92 
93  /* Send request */
94  if ( ( rc = xfer_deliver_raw ( &ntp->xfer, &hdr,
95  sizeof ( hdr ) ) ) != 0 ) {
96  DBGC ( ntp, "NTP %p could not send request: %s\n",
97  ntp, strerror ( rc ) );
98  return rc;
99  }
100 
101  return 0;
102 }
103 
104 /**
105  * Handle NTP response
106  *
107  * @v ntp NTP client
108  * @v iobuf I/O buffer
109  * @v meta Data transfer metadata
110  * @ret rc Return status code
111  */
112 static int ntp_deliver ( struct ntp_client *ntp, struct io_buffer *iobuf,
113  struct xfer_metadata *meta ) {
114  struct ntp_header *hdr;
115  struct sockaddr_tcpip *st_src;
116  int32_t delta;
117  int rc;
118 
119  /* Check source port */
120  st_src = ( ( struct sockaddr_tcpip * ) meta->src );
121  if ( st_src->st_port != htons ( NTP_PORT ) ) {
122  DBGC ( ntp, "NTP %p received non-NTP packet:\n", ntp );
123  DBGC_HDA ( ntp, 0, iobuf->data, iob_len ( iobuf ) );
124  goto ignore;
125  }
126 
127  /* Check packet length */
128  if ( iob_len ( iobuf ) < sizeof ( *hdr ) ) {
129  DBGC ( ntp, "NTP %p received malformed packet:\n", ntp );
130  DBGC_HDA ( ntp, 0, iobuf->data, iob_len ( iobuf ) );
131  goto ignore;
132  }
133  hdr = iobuf->data;
134 
135  /* Check mode */
136  if ( ( hdr->flags & NTP_FL_MODE_MASK ) != NTP_FL_MODE_SERVER ) {
137  DBGC ( ntp, "NTP %p received non-server packet:\n", ntp );
138  DBGC_HDA ( ntp, 0, iobuf->data, iob_len ( iobuf ) );
139  goto ignore;
140  }
141 
142  /* Check magic value */
143  if ( hdr->originate.fraction != htonl ( NTP_FRACTION_MAGIC ) ) {
144  DBGC ( ntp, "NTP %p received unrecognised packet:\n", ntp );
145  DBGC_HDA ( ntp, 0, iobuf->data, iob_len ( iobuf ) );
146  goto ignore;
147  }
148 
149  /* Check for Kiss-o'-Death packets */
150  if ( ! hdr->stratum ) {
151  DBGC ( ntp, "NTP %p received kiss-o'-death:\n", ntp );
152  DBGC_HDA ( ntp, 0, iobuf->data, iob_len ( iobuf ) );
153  rc = -EPROTO;
154  goto close;
155  }
156 
157  /* Calculate clock delta */
158  delta = ( ntohl ( hdr->receive.seconds ) -
159  ntohl ( hdr->originate.seconds ) );
160  DBGC ( ntp, "NTP %p delta %d seconds\n", ntp, delta );
161 
162  /* Adjust system clock */
163  time_adjust ( delta );
164 
165  /* Success */
166  rc = 0;
167 
168  close:
169  ntp_close ( ntp, rc );
170  ignore:
171  free_iob ( iobuf );
172  return 0;
173 }
174 
175 /**
176  * Handle data transfer window change
177  *
178  * @v ntp NTP client
179  */
180 static void ntp_window_changed ( struct ntp_client *ntp ) {
181 
182  /* Start timer to send initial request */
183  start_timer_nodelay ( &ntp->timer );
184 }
185 
186 /** Data transfer interface operations */
187 static struct interface_operation ntp_xfer_op[] = {
191  INTF_OP ( intf_close, struct ntp_client *, ntp_close ),
192 };
193 
194 /** Data transfer interface descriptor */
196  INTF_DESC_PASSTHRU ( struct ntp_client, xfer, ntp_xfer_op, job );
197 
198 /** Job control interface operations */
199 static struct interface_operation ntp_job_op[] = {
200  INTF_OP ( intf_close, struct ntp_client *, ntp_close ),
201 };
202 
203 /** Job control interface descriptor */
205  INTF_DESC_PASSTHRU ( struct ntp_client, job, ntp_job_op, xfer );
206 
207 /**
208  * Handle NTP timer expiry
209  *
210  * @v timer Retransmission timer
211  * @v fail Failure indicator
212  */
213 static void ntp_expired ( struct retry_timer *timer, int fail ) {
214  struct ntp_client *ntp =
215  container_of ( timer, struct ntp_client, timer );
216 
217  /* Shut down client if we have failed */
218  if ( fail ) {
219  ntp_close ( ntp, -ETIMEDOUT );
220  return;
221  }
222 
223  /* Otherwise, restart timer and (re)transmit request */
224  start_timer ( &ntp->timer );
225  ntp_request ( ntp );
226 }
227 
228 /**
229  * Start NTP client
230  *
231  * @v job Job control interface
232  * @v hostname NTP server
233  * @ret rc Return status code
234  */
235 int start_ntp ( struct interface *job, const char *hostname ) {
236  struct ntp_client *ntp;
237  union {
238  struct sockaddr_tcpip st;
239  struct sockaddr sa;
240  } server;
241  int rc;
242 
243  /* Allocate and initialise structure*/
244  ntp = zalloc ( sizeof ( *ntp ) );
245  if ( ! ntp ) {
246  rc = -ENOMEM;
247  goto err_alloc;
248  }
249  ref_init ( &ntp->refcnt, NULL );
250  intf_init ( &ntp->job, &ntp_job_desc, &ntp->refcnt );
251  intf_init ( &ntp->xfer, &ntp_xfer_desc, &ntp->refcnt );
252  timer_init ( &ntp->timer, ntp_expired, &ntp->refcnt );
253  set_timer_limits ( &ntp->timer, NTP_MIN_TIMEOUT, NTP_MAX_TIMEOUT );
254 
255  /* Open socket */
256  memset ( &server, 0, sizeof ( server ) );
257  server.st.st_port = htons ( NTP_PORT );
258  if ( ( rc = xfer_open_named_socket ( &ntp->xfer, SOCK_DGRAM, &server.sa,
259  hostname, NULL ) ) != 0 ) {
260  DBGC ( ntp, "NTP %p could not open socket: %s\n",
261  ntp, strerror ( rc ) );
262  goto err_open;
263  }
264 
265  /* Attach parent interface, mortalise self, and return */
266  intf_plug_plug ( &ntp->job, job );
267  ref_put ( &ntp->refcnt );
268  return 0;
269 
270  err_open:
271  ntp_close ( ntp, rc );
272  ref_put ( &ntp->refcnt );
273  err_alloc:
274  return rc;
275 }
An object interface operation.
Definition: interface.h:17
TCP/IP socket address.
Definition: tcpip.h:75
struct arbelprm_rc_send_wqe rc
Definition: arbel.h:14
void xfer_window_changed(struct interface *intf)
Report change of flow control window.
Definition: xfer.c:145
void intf_close(struct interface *intf, int rc)
Close an object interface.
Definition: interface.c:244
Data transfer metadata.
Definition: xfer.h:22
void intf_shutdown(struct interface *intf, int rc)
Shut down an object interface.
Definition: interface.c:273
static void start_timer_nodelay(struct retry_timer *timer)
Start timer with no delay.
Definition: retry.h:99
static void ntp_window_changed(struct ntp_client *ntp)
Handle data transfer window change.
Definition: ntp.c:180
#define ref_init(refcnt, free)
Initialise a reference counter.
Definition: refcnt.h:64
Error codes.
I/O buffers.
void free_iob(struct io_buffer *iobuf)
Free I/O buffer.
Definition: iobuf.c:145
#define SOCK_DGRAM
Definition: socket.h:29
Retry timers.
#define DBGC(...)
Definition: compiler.h:505
A retry timer.
Definition: retry.h:21
void intf_plug_plug(struct interface *a, struct interface *b)
Plug two object interfaces together.
Definition: interface.c:102
#define ntohl(value)
Definition: byteswap.h:134
#define NTP_EPOCH
NTP timestamp for start of Unix epoch.
Definition: ntp.h:87
int start_ntp(struct interface *job, const char *hostname)
Start NTP client.
Definition: ntp.c:235
iPXE timers
An NTP header.
Definition: ntp.h:46
#define NTP_FL_VN_1
NTP version: 1.
Definition: ntp.h:75
Network Time Protocol.
#define htonl(value)
Definition: byteswap.h:133
#define NTP_FL_MODE_CLIENT
NTP mode: client.
Definition: ntp.h:78
int xfer_deliver_raw(struct interface *intf, const void *data, size_t len)
Deliver datagram as raw data without metadata.
Definition: xfer.c:287
Dynamic memory allocation.
Data transfer interfaces.
A reference counter.
Definition: refcnt.h:26
#define NTP_FRACTION_MAGIC
NTP fraction of a second magic value.
Definition: ntp.h:93
A timer.
Definition: timer.h:28
struct sockaddr_tcpip st
Definition: syslog.c:56
An NTP client.
Definition: ntp.c:48
#define ENOMEM
Not enough space.
Definition: errno.h:534
#define container_of(ptr, type, field)
Get containing structure.
Definition: stddef.h:35
An object interface.
Definition: interface.h:109
#define DBGC_HDA(...)
Definition: compiler.h:506
struct interface xfer
Data transfer interface.
Definition: ntp.c:54
struct sockaddr sa
Definition: syslog.c:55
Transport-network layer interface.
int ntp(const char *hostname)
Get time and date via NTP.
Definition: ntpmgmt.c:45
#define EPROTO
Protocol error.
Definition: errno.h:624
int meta(WINDOW *, bool)
uint16_t st_port
TCP/IP port.
Definition: tcpip.h:81
Generalized socket address structure.
Definition: socket.h:96
An object interface descriptor.
Definition: interface.h:40
#define NTP_PORT
NTP port.
Definition: ntp.h:17
char * strerror(int errno)
Retrieve string representation of error number.
Definition: strerror.c:78
void * zalloc(size_t size)
Allocate cleared memory.
Definition: malloc.c:624
static size_t iob_len(struct io_buffer *iobuf)
Calculate length of data in an I/O buffer.
Definition: iobuf.h:151
#define INTF_OP(op_type, object_type, op_func)
Define an object interface operation.
Definition: interface.h:32
static struct interface_descriptor ntp_xfer_desc
Data transfer interface descriptor.
Definition: ntp.c:195
static struct interface_descriptor ntp_job_desc
Job control interface descriptor.
Definition: ntp.c:204
static int ntp_request(struct ntp_client *ntp)
Send NTP request.
Definition: ntp.c:81
int xfer_deliver(struct interface *intf, struct io_buffer *iobuf, struct xfer_metadata *meta)
Deliver datagram.
Definition: xfer.c:193
Data transfer interface opening.
#define NTP_FL_LI_UNKNOWN
Leap second indicator: unknown.
Definition: ntp.h:72
#define NTP_MIN_TIMEOUT
NTP minimum retransmission timeout.
Definition: ntp.h:99
void start_timer(struct retry_timer *timer)
Start timer.
Definition: retry.c:93
uint32_t hdr
Message header.
Definition: intelvf.h:12
static int ntp_deliver(struct ntp_client *ntp, struct io_buffer *iobuf, struct xfer_metadata *meta)
Handle NTP response.
Definition: ntp.c:112
void stop_timer(struct retry_timer *timer)
Stop timer.
Definition: retry.c:117
static struct interface_operation ntp_xfer_op[]
Data transfer interface operations.
Definition: ntp.c:187
static void ntp_close(struct ntp_client *ntp, int rc)
Close NTP client.
Definition: ntp.c:65
signed int int32_t
Definition: stdint.h:17
#define NTP_MAX_TIMEOUT
NTP maximum retransmission timeout.
Definition: ntp.h:105
void * data
Start of data.
Definition: iobuf.h:44
Reference counting.
static void ntp_expired(struct retry_timer *timer, int fail)
Handle NTP timer expiry.
Definition: ntp.c:213
#define INTF_DESC_PASSTHRU(object_type, intf, operations, passthru)
Define an object interface descriptor with pass-through interface.
Definition: interface.h:82
#define NTP_FL_MODE_SERVER
NTP mode: server.
Definition: ntp.h:81
static struct evtchn_close * close
Definition: xenevent.h:23
#define NTP_FL_MODE_MASK
NTP mode mask.
Definition: ntp.h:84
static void intf_init(struct interface *intf, struct interface_descriptor *desc, struct refcnt *refcnt)
Initialise an object interface.
Definition: interface.h:173
Time source.
struct interface job
Job control interface.
Definition: ntp.c:52
uint64_t time
Current time.
Definition: ntlm.h:20
#define NULL
NULL pointer (VOID *)
Definition: Base.h:362
#define ETIMEDOUT
Connection timed out.
Definition: errno.h:669
String functions.
static struct interface_operation ntp_job_op[]
Job control interface operations.
Definition: ntp.c:199
#define htons(value)
Definition: byteswap.h:135
FILE_LICENCE(GPL2_OR_LATER_OR_UBDL)
int xfer_open_named_socket(struct interface *xfer, int semantics, struct sockaddr *peer, const char *name, struct sockaddr *local)
Open named socket.
Definition: resolv.c:402
#define ref_put(refcnt)
Drop reference to object.
Definition: refcnt.h:106
void * memset(void *dest, int character, size_t len) __nonnull
A persistent I/O buffer.
Definition: iobuf.h:32