c3cf30ac973b54f875d56356fc58910190240e0d
[petitboot] / discover / network.c
1
2 #include <stdbool.h>
3 #include <stdint.h>
4 #include <string.h>
5 #include <stdlib.h>
6 #include <errno.h>
7 #include <sys/socket.h>
8 #include <linux/if.h>
9 #include <linux/netlink.h>
10 #include <linux/rtnetlink.h>
11 #include <i18n/i18n.h>
12
13 #include <log/log.h>
14 #include <list/list.h>
15 #include <file/file.h>
16 #include <types/types.h>
17 #include <talloc/talloc.h>
18 #include <waiter/waiter.h>
19 #include <process/process.h>
20 #include <system/system.h>
21
22 #include "network.h"
23 #include "sysinfo.h"
24 #include "platform.h"
25 #include "device-handler.h"
26
27 #define HWADDR_SIZE     6
28 #define PIDFILE_BASE    (LOCAL_STATE_DIR "/petitboot/")
29 #define INITIAL_BUFSIZE 4096
30
31 #define for_each_nlmsg(buf, nlmsg, len) \
32         for (nlmsg = (struct nlmsghdr *)buf; \
33                 NLMSG_OK(nlmsg, len) && nlmsg->nlmsg_type != NLMSG_DONE; \
34                 nlmsg = NLMSG_NEXT(nlmsg, len))
35
36 #define for_each_rta(buf, rta, attrlen) \
37         for (rta = (struct rtattr *)(buf); RTA_OK(rta, attrlen); \
38                         rta = RTA_NEXT(rta, attrlen))
39
40
41 struct interface {
42         int     ifindex;
43         char    name[IFNAMSIZ];
44         uint8_t hwaddr[HWADDR_SIZE];
45
46         enum {
47                 IFSTATE_NEW,
48                 IFSTATE_UP_WAITING_LINK,
49                 IFSTATE_CONFIGURED,
50                 IFSTATE_IGNORED,
51         } state;
52
53         struct list_item list;
54         struct process *udhcpc_process;
55         struct discover_device *dev;
56 };
57
58 struct network {
59         struct list             interfaces;
60         struct device_handler   *handler;
61         struct waiter           *waiter;
62         int                     netlink_sd;
63         void                    *netlink_buf;
64         unsigned int            netlink_buf_size;
65         bool                    manual_config;
66         bool                    dry_run;
67 };
68
69 static char *mac_bytes_to_string(void *ctx, uint8_t *addr, int len)
70 {
71         const int l = strlen("xx:");
72         char *buf;
73         int i;
74
75         if (len <= 0)
76                 return talloc_strdup(ctx, "");
77
78         buf = talloc_array(ctx, char, (len * l) + 1);
79
80         for (i = 0; i < len; i++)
81                 sprintf(buf + (l * i), "%02x:", addr[i]);
82
83         *(buf + (l * len) - 1) = '\0';
84
85         return buf;
86 }
87
88 static const struct interface_config *find_config_by_hwaddr(
89                 uint8_t *hwaddr)
90 {
91         const struct config *config;
92         unsigned int i;
93
94         config = config_get();
95         if (!config)
96                 return NULL;
97
98         for (i = 0; i < config->network.n_interfaces; i++) {
99                 struct interface_config *ifconf = config->network.interfaces[i];
100
101                 if (!memcmp(ifconf->hwaddr, hwaddr, HWADDR_SIZE))
102                         return ifconf;
103         }
104
105         return NULL;
106 }
107
108 static struct interface *find_interface_by_ifindex(struct network *network,
109                 int ifindex)
110 {
111         struct interface *interface;
112
113         list_for_each_entry(&network->interfaces, interface, list)
114                 if (interface->ifindex == ifindex)
115                         return interface;
116
117         return NULL;
118 }
119
120 static struct interface *find_interface_by_name(struct network *network,
121                 const char *name)
122 {
123         struct interface *interface;
124
125         list_for_each_entry(&network->interfaces, interface, list)
126                 if (!strcmp(interface->name, name))
127                         return interface;
128
129         return NULL;
130 }
131
132 static struct interface *find_interface_by_uuid(struct network *network,
133                 const char *uuid)
134 {
135         struct interface *interface;
136         char *mac;
137
138         list_for_each_entry(&network->interfaces, interface, list) {
139                 mac = mac_bytes_to_string(interface, interface->hwaddr,
140                                         sizeof(interface->hwaddr));
141                 if (!strcmp(mac, uuid)) {
142                         talloc_free(mac);
143                         return interface;
144                 }
145                 talloc_free(mac);
146         }
147
148         return NULL;
149 }
150
151 uint8_t *find_mac_by_name(void *ctx, struct network *network,
152                 const char *name)
153 {
154         struct interface *interface;
155
156         interface = find_interface_by_name(network, name);
157         if (!interface)
158                 return NULL;
159
160         return talloc_memdup(ctx, &interface->hwaddr,
161                              sizeof(uint8_t) * HWADDR_SIZE);
162 }
163
164 static int network_init_netlink(struct network *network)
165 {
166         struct sockaddr_nl addr;
167         int rc;
168
169         memset(&addr, 0, sizeof(addr));
170         addr.nl_family = AF_NETLINK;
171         addr.nl_groups = RTMGRP_LINK;
172
173         network->netlink_sd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
174         if (network->netlink_sd < 0) {
175                 perror("socket(AF_NETLINK)");
176                 return -1;
177         }
178
179         rc = bind(network->netlink_sd, (struct sockaddr *)&addr, sizeof(addr));
180         if (rc) {
181                 perror("bind(sockaddr_nl)");
182                 close(network->netlink_sd);
183                 return -1;
184         }
185
186         network->netlink_buf_size = INITIAL_BUFSIZE;
187         network->netlink_buf = talloc_array(network, char,
188                                 network->netlink_buf_size);
189
190         return 0;
191 }
192
193 static int network_send_link_query(struct network *network)
194 {
195         int rc;
196         struct {
197                 struct nlmsghdr nlmsg;
198                 struct rtgenmsg rtmsg;
199         } msg;
200
201         memset(&msg, 0, sizeof(msg));
202
203         msg.nlmsg.nlmsg_len = sizeof(msg);
204         msg.nlmsg.nlmsg_type = RTM_GETLINK;
205         msg.nlmsg.nlmsg_flags = NLM_F_REQUEST | NLM_F_ROOT;
206         msg.nlmsg.nlmsg_seq = 0;
207         msg.nlmsg.nlmsg_pid = 0;
208         msg.rtmsg.rtgen_family = AF_UNSPEC;
209
210         rc = send(network->netlink_sd, &msg, sizeof(msg), MSG_NOSIGNAL);
211         if (rc != sizeof(msg))
212                 return -1;
213
214         return 0;
215 }
216
217 static void add_interface(struct network *network,
218                 struct interface *interface)
219 {
220         char *uuid = mac_bytes_to_string(interface, interface->hwaddr,
221                                                 sizeof(interface->hwaddr));
222
223         list_add(&network->interfaces, &interface->list);
224         interface->dev = discover_device_create(network->handler, uuid,
225                                                 interface->name);
226         interface->dev->device->type = DEVICE_TYPE_NETWORK;
227         device_handler_add_device(network->handler, interface->dev);
228         talloc_free(uuid);
229 }
230
231 static void remove_interface(struct network *network,
232                 struct interface *interface)
233 {
234         if (interface->dev)
235                 device_handler_remove(network->handler, interface->dev);
236         list_remove(&interface->list);
237         talloc_free(interface);
238 }
239
240 void network_register_device(struct network *network,
241                 struct discover_device *dev)
242 {
243         struct interface *iface;
244
245         if (dev->uuid)
246                 iface = find_interface_by_uuid(network, dev->uuid);
247         else
248                 iface = find_interface_by_name(network, dev->label);
249         if (!iface)
250                 return;
251
252         iface->dev = dev;
253         dev->uuid = mac_bytes_to_string(iface->dev, iface->hwaddr,
254                         sizeof(iface->hwaddr));
255 }
256
257 void network_unregister_device(struct network *network,
258                 struct discover_device *dev)
259 {
260         struct interface *iface;
261
262         iface = find_interface_by_uuid(network, dev->uuid);
263         if (!iface)
264                 return;
265
266         iface->dev = NULL;
267 }
268
269 static int interface_change(struct interface *interface, bool up)
270 {
271         const char *statestr = up ? "up" : "down";
272         int rc;
273
274         if (!up && interface->udhcpc_process) {
275                 /* we don't care about the callback from here */
276                 interface->udhcpc_process->exit_cb = NULL;
277                 interface->udhcpc_process->data = NULL;
278                 process_stop_async(interface->udhcpc_process);
279                 process_release(interface->udhcpc_process);
280         }
281
282         if (!up) {
283                 rc = process_run_simple(interface, pb_system_apps.ip,
284                                 "address", "flush", "dev", interface->name,
285                                 NULL);
286                 if (rc)
287                         pb_log("failed to flush addresses from interface %s\n",
288                                 interface->name);
289         }
290
291         rc = process_run_simple(interface, pb_system_apps.ip,
292                         "link", "set", interface->name, statestr, NULL);
293         if (rc) {
294                 pb_log("failed to bring interface %s %s\n", interface->name,
295                                 statestr);
296                 return -1;
297         }
298         return 0;
299 }
300
301 static int interface_up(struct interface *interface)
302 {
303         return interface_change(interface, true);
304 }
305
306 static int interface_down(struct interface *interface)
307 {
308         return interface_change(interface, false);
309 }
310
311 static void udhcpc_process_exit(struct process *process)
312 {
313         struct interface *interface = process->data;
314         pb_debug("udhcp client [pid %d] for interface %s exited, rc %d\n",
315                         process->pid, interface->name, process->exit_status);
316         interface->udhcpc_process = NULL;
317         process_release(process);
318 }
319
320 static void configure_interface_dhcp(struct network *network,
321                 struct interface *interface)
322 {
323         const struct platform *platform;
324         char pidfile[256], id[10];
325         struct process *process;
326         int rc;
327         const char *argv[] = {
328                 pb_system_apps.udhcpc,
329                 "-R",
330                 "-f",
331                 "-O", "pxeconffile",
332                 "-O", "pxepathprefix",
333                 "-p", pidfile,
334                 "-i", interface->name,
335                 "-x", id, /* [11,12] - dhcp client identifier */
336                 NULL,
337         };
338
339         device_handler_status_dev_info(network->handler, interface->dev,
340                         _("Configuring with DHCP"));
341
342         snprintf(pidfile, sizeof(pidfile), "%s/udhcpc-%s.pid",
343                         PIDFILE_BASE, interface->name);
344
345         platform = platform_get();
346         if (platform && platform->dhcp_arch_id != 0xffff)
347                 snprintf(id, sizeof(id), "0x5d:%04x", platform->dhcp_arch_id);
348         else
349                 argv[11] = NULL;
350
351         process = process_create(interface);
352
353         process->path = pb_system_apps.udhcpc;
354         process->argv = argv;
355         process->exit_cb = udhcpc_process_exit;
356         process->data = interface;
357
358         rc = process_run_async(process);
359
360         if (rc)
361                 process_release(process);
362         else
363                 interface->udhcpc_process = process;
364
365         return;
366 }
367
368 static void configure_interface_static(struct network *network,
369                 struct interface *interface,
370                 const struct interface_config *config)
371 {
372         int rc;
373
374         device_handler_status_dev_info(network->handler, interface->dev,
375                         _("Configuring with static address (ip: %s)"),
376                         config->static_config.address);
377
378         rc = process_run_simple(interface, pb_system_apps.ip,
379                         "address", "add", config->static_config.address,
380                         "dev", interface->name, NULL);
381
382
383         if (rc) {
384                 pb_log("failed to add address %s to interface %s\n",
385                                 config->static_config.address,
386                                 interface->name);
387                 return;
388         }
389
390         system_info_set_interface_address(sizeof(interface->hwaddr),
391                                 interface->hwaddr,
392                                 config->static_config.address);
393
394         /* we need the interface up before we can route through it */
395         rc = interface_up(interface);
396         if (rc)
397                 return;
398
399         if (config->static_config.gateway)
400                 rc = process_run_simple(interface, pb_system_apps.ip,
401                                 "route", "add", "default",
402                                 "via", config->static_config.gateway,
403                                 NULL);
404
405         if (rc) {
406                 pb_log("failed to add default route %s on interface %s\n",
407                                 config->static_config.gateway,
408                                 interface->name);
409         }
410
411         if (config->static_config.url) {
412                 pb_log("config URL %s\n", config->static_config.url);
413                 device_handler_process_url(network->handler,
414                                 config->static_config.url,
415                                 mac_bytes_to_string(interface->dev,
416                                                 interface->hwaddr,
417                                                 sizeof(interface->hwaddr)),
418                                 config->static_config.address);
419         }
420
421         return;
422 }
423
424 static void configure_interface(struct network *network,
425                 struct interface *interface, bool up, bool link)
426 {
427         const struct interface_config *config = NULL;
428
429         if (interface->state == IFSTATE_IGNORED)
430                 return;
431
432         /* old interface? check that we're still up and running */
433         if (interface->state == IFSTATE_CONFIGURED) {
434                 if (!up)
435                         interface->state = IFSTATE_NEW;
436                 else if (!link)
437                         interface->state = IFSTATE_UP_WAITING_LINK;
438                 else {
439                         pb_debug("network: skipping configured interface %s\n",
440                                         interface->name);
441                         return;
442                 }
443         }
444
445         /* always up the lookback, no other handling required */
446         if (!strcmp(interface->name, "lo")) {
447                 if (interface->state == IFSTATE_NEW)
448                         interface_up(interface);
449                 interface->state = IFSTATE_CONFIGURED;
450                 return;
451         }
452
453         config = find_config_by_hwaddr(interface->hwaddr);
454         if (config && config->ignore) {
455                 pb_log("network: ignoring interface %s\n", interface->name);
456                 interface->state = IFSTATE_IGNORED;
457                 return;
458         }
459
460         /* if we're in manual config mode, we need an interface configuration */
461         if (network->manual_config && !config) {
462                 interface->state = IFSTATE_IGNORED;
463                 pb_log("network: skipping %s: manual config mode, "
464                                 "but no config for this interface\n",
465                                 interface->name);
466                 return;
467         }
468
469         /* new interface? bring up to the point so we can detect a link */
470         if (interface->state == IFSTATE_NEW) {
471                 if (!up) {
472                         interface_up(interface);
473                         pb_log("network: bringing up interface %s\n",
474                                         interface->name);
475                         return;
476
477                 } else if (!link) {
478                         interface->state = IFSTATE_UP_WAITING_LINK;
479                 }
480         }
481
482         /* no link? wait for a notification */
483         if (interface->state == IFSTATE_UP_WAITING_LINK && !link)
484                 return;
485
486         pb_log("network: configuring interface %s\n", interface->name);
487
488         if (!config || config->method == CONFIG_METHOD_DHCP) {
489                 configure_interface_dhcp(network, interface);
490
491         } else if (config->method == CONFIG_METHOD_STATIC) {
492                 configure_interface_static(network, interface, config);
493         }
494
495         interface->state = IFSTATE_CONFIGURED;
496 }
497
498 static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
499 {
500         bool have_ifaddr, have_ifname;
501         struct interface *interface;
502         struct ifinfomsg *info;
503         struct rtattr *attr;
504         unsigned int mtu;
505         uint8_t ifaddr[6];
506         char ifname[IFNAMSIZ+1];
507         int attrlen, type;
508
509
510         /* we're only interested in NEWLINK messages */
511         type = nlmsg->nlmsg_type;
512         if (!(type == RTM_NEWLINK || type == RTM_DELLINK))
513                 return 0;
514
515         info = NLMSG_DATA(nlmsg);
516
517         have_ifaddr = have_ifname = false;
518         mtu = 1;
519
520         attrlen = nlmsg->nlmsg_len - sizeof(*info);
521
522         /* extract the interface name and hardware address attributes */
523         for_each_rta(info + 1, attr, attrlen) {
524                 void *data = RTA_DATA(attr);
525
526                 switch (attr->rta_type) {
527                 case IFLA_ADDRESS:
528                         memcpy(ifaddr, data, sizeof(ifaddr));
529                         have_ifaddr = true;
530                         break;
531
532                 case IFLA_IFNAME:
533                         strncpy(ifname, data, IFNAMSIZ);
534                         have_ifname = true;
535                         break;
536
537                 case IFLA_MTU:
538                         mtu = *(unsigned int *)data;
539                         break;
540                 }
541         }
542
543         if (!have_ifaddr || !have_ifname)
544                 return -1;
545
546         if (type == RTM_DELLINK || mtu == 0) {
547                 interface = find_interface_by_ifindex(network, info->ifi_index);
548                 if (!interface)
549                         return 0;
550                 pb_log("network: interface %s removed\n", interface->name);
551                 remove_interface(network, interface);
552                 return 0;
553         }
554
555         /* ignore the default tun device in some environments */
556         if (strncmp(ifname, "tun", strlen("tun")) == 0)
557                 return 0;
558
559         interface = find_interface_by_ifindex(network, info->ifi_index);
560         if (!interface) {
561                 interface = talloc_zero(network, struct interface);
562                 interface->ifindex = info->ifi_index;
563                 interface->state = IFSTATE_NEW;
564                 memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr));
565                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
566                 add_interface(network, interface);
567         }
568
569         /* A repeated RTM_NEWLINK can represent an interface name change */
570         if (strncmp(interface->name, ifname, IFNAMSIZ)) {
571                 pb_debug("ifname update: %s -> %s\n", interface->name, ifname);
572                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
573                 talloc_free(interface->dev->device->id);
574                 interface->dev->device->id =
575                         talloc_strdup(interface->dev->device, ifname);
576         }
577
578         /* notify the sysinfo code about changes to this interface */
579         if (strcmp(interface->name, "lo"))
580                 system_info_register_interface(
581                                 sizeof(interface->hwaddr),
582                                 interface->hwaddr, interface->name,
583                                 info->ifi_flags & IFF_LOWER_UP);
584
585         configure_interface(network, interface,
586                         info->ifi_flags & IFF_UP,
587                         info->ifi_flags & IFF_LOWER_UP);
588
589         return 0;
590 }
591
592 static int network_netlink_process(void *arg)
593 {
594         struct network *network = arg;
595         struct nlmsghdr *nlmsg;
596         struct msghdr msg;
597         struct iovec iov;
598         unsigned int len;
599         int rc, flags;
600
601         memset(&msg, 0, sizeof(msg));
602         msg.msg_iov = &iov;
603         msg.msg_iovlen = 1;
604
605         flags = MSG_PEEK;
606
607 retry:
608         iov.iov_len = network->netlink_buf_size;
609         iov.iov_base = network->netlink_buf;
610
611         rc = recvmsg(network->netlink_sd, &msg, flags);
612
613         if (rc < 0) {
614                 perror("netlink recv header");
615                 return -1;
616         }
617
618         len = rc;
619
620         /* if the netlink message was larger than our buffer, realloc
621          * before reading again */
622         if (len > network->netlink_buf_size || msg.msg_flags & MSG_TRUNC) {
623                 network->netlink_buf_size *= 2;
624                 network->netlink_buf = talloc_realloc(network,
625                                         network->netlink_buf,
626                                         char *,
627                                         network->netlink_buf_size);
628                 goto retry;
629         }
630
631         /* otherwise, we're good to read the entire message without PEEK */
632         if (flags == MSG_PEEK) {
633                 flags = 0;
634                 goto retry;
635         }
636
637         for_each_nlmsg(network->netlink_buf, nlmsg, len)
638                 network_handle_nlmsg(network, nlmsg);
639
640         return 0;
641 }
642
643 static void network_init_dns(struct network *network)
644 {
645         const struct config *config;
646         unsigned int i;
647         int rc, len;
648         bool modified;
649         char *buf;
650
651         if (network->dry_run)
652                 return;
653
654         config = config_get();
655         if (!config || !config->network.n_dns_servers)
656                 return;
657
658         rc = read_file(network, "/etc/resolv.conf", &buf, &len);
659
660         if (rc) {
661                 buf = talloc_strdup(network, "");
662                 len = 0;
663         }
664
665         modified = false;
666
667         for (i = 0; i < config->network.n_dns_servers; i++) {
668                 int dns_conf_len;
669                 char *dns_conf;
670
671                 dns_conf = talloc_asprintf(network, "nameserver %s\n",
672                                 config->network.dns_servers[i]);
673
674                 if (strstr(buf, dns_conf)) {
675                         talloc_free(dns_conf);
676                         continue;
677                 }
678
679                 dns_conf_len = strlen(dns_conf);
680                 buf = talloc_realloc(network, buf, char, len + dns_conf_len + 1);
681                 memcpy(buf + len, dns_conf, dns_conf_len);
682                 len += dns_conf_len;
683                 buf[len] = '\0';
684                 modified = true;
685
686                 talloc_free(dns_conf);
687         }
688
689         if (modified) {
690                 rc = replace_file("/etc/resolv.conf", buf, len);
691                 if (rc)
692                         pb_log("error replacing resolv.conf: %s\n",
693                                         strerror(errno));
694         }
695
696         talloc_free(buf);
697 }
698
699 struct network *network_init(struct device_handler *handler,
700                 struct waitset *waitset, bool dry_run)
701 {
702         struct network *network;
703         int rc;
704
705         network = talloc(handler, struct network);
706         list_init(&network->interfaces);
707         network->handler = handler;
708         network->dry_run = dry_run;
709         network->manual_config = config_get()->network.n_interfaces != 0;
710
711         network_init_dns(network);
712
713         rc = network_init_netlink(network);
714         if (rc)
715                 goto err;
716
717         network->waiter = waiter_register_io(waitset, network->netlink_sd,
718                         WAIT_IN, network_netlink_process, network);
719
720         if (!network->waiter)
721                 goto err;
722
723         rc = network_send_link_query(network);
724         if (rc)
725                 goto err;
726
727         return network;
728
729 err:
730         network_shutdown(network);
731         return NULL;
732 }
733
734 int network_shutdown(struct network *network)
735 {
736         struct interface *interface;
737
738         if (network->waiter)
739                 waiter_remove(network->waiter);
740
741         list_for_each_entry(&network->interfaces, interface, list) {
742                 if (interface->state == IFSTATE_IGNORED)
743                         continue;
744                 if (!strcmp(interface->name, "lo"))
745                         continue;
746                 interface_down(interface);
747         }
748
749         close(network->netlink_sd);
750         talloc_free(network);
751         return 0;
752 }