discover/status: report status on link configuration
[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         iface = find_interface_by_uuid(network, dev->uuid);
246         if (!iface)
247                 return;
248
249         iface->dev = dev;
250         dev->uuid = mac_bytes_to_string(iface->dev, iface->hwaddr,
251                         sizeof(iface->hwaddr));
252 }
253
254 void network_unregister_device(struct network *network,
255                 struct discover_device *dev)
256 {
257         struct interface *iface;
258
259         iface = find_interface_by_uuid(network, dev->uuid);
260         if (!iface)
261                 return;
262
263         iface->dev = NULL;
264 }
265
266 static int interface_change(struct interface *interface, bool up)
267 {
268         const char *statestr = up ? "up" : "down";
269         int rc;
270
271         if (!up && interface->udhcpc_process) {
272                 /* we don't care about the callback from here */
273                 interface->udhcpc_process->exit_cb = NULL;
274                 interface->udhcpc_process->data = NULL;
275                 process_stop_async(interface->udhcpc_process);
276                 process_release(interface->udhcpc_process);
277         }
278
279         if (!up) {
280                 rc = process_run_simple(interface, pb_system_apps.ip,
281                                 "address", "flush", "dev", interface->name,
282                                 NULL);
283                 if (rc)
284                         pb_log("failed to flush addresses from interface %s\n",
285                                 interface->name);
286         }
287
288         rc = process_run_simple(interface, pb_system_apps.ip,
289                         "link", "set", interface->name, statestr, NULL);
290         if (rc) {
291                 pb_log("failed to bring interface %s %s\n", interface->name,
292                                 statestr);
293                 return -1;
294         }
295         return 0;
296 }
297
298 static int interface_up(struct interface *interface)
299 {
300         return interface_change(interface, true);
301 }
302
303 static int interface_down(struct interface *interface)
304 {
305         return interface_change(interface, false);
306 }
307
308 static void udhcpc_process_exit(struct process *process)
309 {
310         struct interface *interface = process->data;
311         pb_debug("udhcp client [pid %d] for interface %s exited, rc %d\n",
312                         process->pid, interface->name, process->exit_status);
313         interface->udhcpc_process = NULL;
314         process_release(process);
315 }
316
317 static void configure_interface_dhcp(struct network *network,
318                 struct interface *interface)
319 {
320         const struct platform *platform;
321         char pidfile[256], id[10];
322         struct process *process;
323         int rc;
324         const char *argv[] = {
325                 pb_system_apps.udhcpc,
326                 "-R",
327                 "-f",
328                 "-O", "pxeconffile",
329                 "-O", "pxepathprefix",
330                 "-p", pidfile,
331                 "-i", interface->name,
332                 "-x", id, /* [11,12] - dhcp client identifier */
333                 NULL,
334         };
335
336         device_handler_status_dev_info(network->handler, interface->dev,
337                         _("Configuring with DHCP"));
338
339         snprintf(pidfile, sizeof(pidfile), "%s/udhcpc-%s.pid",
340                         PIDFILE_BASE, interface->name);
341
342         platform = platform_get();
343         if (platform && platform->dhcp_arch_id != 0xffff)
344                 snprintf(id, sizeof(id), "0x5d:%04x", platform->dhcp_arch_id);
345         else
346                 argv[11] = NULL;
347
348         process = process_create(interface);
349
350         process->path = pb_system_apps.udhcpc;
351         process->argv = argv;
352         process->exit_cb = udhcpc_process_exit;
353         process->data = interface;
354
355         rc = process_run_async(process);
356
357         if (rc)
358                 process_release(process);
359         else
360                 interface->udhcpc_process = process;
361
362         return;
363 }
364
365 static void configure_interface_static(struct network *network,
366                 struct interface *interface,
367                 const struct interface_config *config)
368 {
369         int rc;
370
371         device_handler_status_dev_info(network->handler, interface->dev,
372                         _("Configuring with static address (ip: %s)"),
373                         config->static_config.address);
374
375         rc = process_run_simple(interface, pb_system_apps.ip,
376                         "address", "add", config->static_config.address,
377                         "dev", interface->name, NULL);
378
379
380         if (rc) {
381                 pb_log("failed to add address %s to interface %s\n",
382                                 config->static_config.address,
383                                 interface->name);
384                 return;
385         }
386
387         /* we need the interface up before we can route through it */
388         rc = interface_up(interface);
389         if (rc)
390                 return;
391
392         if (config->static_config.gateway)
393                 rc = process_run_simple(interface, pb_system_apps.ip,
394                                 "route", "add", "default",
395                                 "via", config->static_config.gateway,
396                                 NULL);
397
398         if (rc) {
399                 pb_log("failed to add default route %s on interface %s\n",
400                                 config->static_config.gateway,
401                                 interface->name);
402         }
403
404         if (config->static_config.url) {
405                 pb_log("config URL %s\n", config->static_config.url);
406                 device_handler_process_url(network->handler,
407                                 config->static_config.url,
408                                 mac_bytes_to_string(interface->dev,
409                                                 interface->hwaddr,
410                                                 sizeof(interface->hwaddr)),
411                                 config->static_config.address);
412         }
413
414         return;
415 }
416
417 static void configure_interface(struct network *network,
418                 struct interface *interface, bool up, bool link)
419 {
420         const struct interface_config *config = NULL;
421
422         if (interface->state == IFSTATE_IGNORED)
423                 return;
424
425         /* old interface? check that we're still up and running */
426         if (interface->state == IFSTATE_CONFIGURED) {
427                 if (!up)
428                         interface->state = IFSTATE_NEW;
429                 else if (!link)
430                         interface->state = IFSTATE_UP_WAITING_LINK;
431                 else {
432                         pb_debug("network: skipping configured interface %s\n",
433                                         interface->name);
434                         return;
435                 }
436         }
437
438         /* always up the lookback, no other handling required */
439         if (!strcmp(interface->name, "lo")) {
440                 if (interface->state == IFSTATE_NEW)
441                         interface_up(interface);
442                 interface->state = IFSTATE_CONFIGURED;
443                 return;
444         }
445
446         config = find_config_by_hwaddr(interface->hwaddr);
447         if (config && config->ignore) {
448                 pb_log("network: ignoring interface %s\n", interface->name);
449                 interface->state = IFSTATE_IGNORED;
450                 return;
451         }
452
453         /* if we're in manual config mode, we need an interface configuration */
454         if (network->manual_config && !config) {
455                 interface->state = IFSTATE_IGNORED;
456                 pb_log("network: skipping %s: manual config mode, "
457                                 "but no config for this interface\n",
458                                 interface->name);
459                 return;
460         }
461
462         /* new interface? bring up to the point so we can detect a link */
463         if (interface->state == IFSTATE_NEW) {
464                 if (!up) {
465                         interface_up(interface);
466                         pb_log("network: bringing up interface %s\n",
467                                         interface->name);
468                         return;
469
470                 } else if (!link) {
471                         interface->state = IFSTATE_UP_WAITING_LINK;
472                 }
473         }
474
475         /* no link? wait for a notification */
476         if (interface->state == IFSTATE_UP_WAITING_LINK && !link)
477                 return;
478
479         pb_log("network: configuring interface %s\n", interface->name);
480
481         if (!config || config->method == CONFIG_METHOD_DHCP) {
482                 configure_interface_dhcp(network, interface);
483
484         } else if (config->method == CONFIG_METHOD_STATIC) {
485                 configure_interface_static(network, interface, config);
486         }
487
488         interface->state = IFSTATE_CONFIGURED;
489 }
490
491 static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
492 {
493         bool have_ifaddr, have_ifname;
494         struct interface *interface;
495         struct ifinfomsg *info;
496         struct rtattr *attr;
497         unsigned int mtu;
498         uint8_t ifaddr[6];
499         char ifname[IFNAMSIZ+1];
500         int attrlen, type;
501
502
503         /* we're only interested in NEWLINK messages */
504         type = nlmsg->nlmsg_type;
505         if (!(type == RTM_NEWLINK || type == RTM_DELLINK))
506                 return 0;
507
508         info = NLMSG_DATA(nlmsg);
509
510         have_ifaddr = have_ifname = false;
511         mtu = 1;
512
513         attrlen = nlmsg->nlmsg_len - sizeof(*info);
514
515         /* extract the interface name and hardware address attributes */
516         for_each_rta(info + 1, attr, attrlen) {
517                 void *data = RTA_DATA(attr);
518
519                 switch (attr->rta_type) {
520                 case IFLA_ADDRESS:
521                         memcpy(ifaddr, data, sizeof(ifaddr));
522                         have_ifaddr = true;
523                         break;
524
525                 case IFLA_IFNAME:
526                         strncpy(ifname, data, IFNAMSIZ);
527                         have_ifname = true;
528                         break;
529
530                 case IFLA_MTU:
531                         mtu = *(unsigned int *)data;
532                         break;
533                 }
534         }
535
536         if (!have_ifaddr || !have_ifname)
537                 return -1;
538
539         if (type == RTM_DELLINK || mtu == 0) {
540                 interface = find_interface_by_ifindex(network, info->ifi_index);
541                 if (!interface)
542                         return 0;
543                 pb_log("network: interface %s removed\n", interface->name);
544                 remove_interface(network, interface);
545                 return 0;
546         }
547
548         /* ignore the default tun device in some environments */
549         if (strncmp(ifname, "tun", strlen("tun")) == 0)
550                 return 0;
551
552         interface = find_interface_by_ifindex(network, info->ifi_index);
553         if (!interface) {
554                 interface = talloc_zero(network, struct interface);
555                 interface->ifindex = info->ifi_index;
556                 interface->state = IFSTATE_NEW;
557                 memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr));
558                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
559                 add_interface(network, interface);
560         }
561
562         /* A repeated RTM_NEWLINK can represent an interface name change */
563         if (strncmp(interface->name, ifname, IFNAMSIZ)) {
564                 pb_debug("ifname update: %s -> %s\n", interface->name, ifname);
565                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
566                 talloc_free(interface->dev->device->id);
567                 interface->dev->device->id =
568                         talloc_strdup(interface->dev->device, ifname);
569         }
570
571         /* notify the sysinfo code about changes to this interface */
572         if (strcmp(interface->name, "lo"))
573                 system_info_register_interface(
574                                 sizeof(interface->hwaddr),
575                                 interface->hwaddr, interface->name,
576                                 info->ifi_flags & IFF_LOWER_UP);
577
578         configure_interface(network, interface,
579                         info->ifi_flags & IFF_UP,
580                         info->ifi_flags & IFF_LOWER_UP);
581
582         return 0;
583 }
584
585 static int network_netlink_process(void *arg)
586 {
587         struct network *network = arg;
588         struct nlmsghdr *nlmsg;
589         struct msghdr msg;
590         struct iovec iov;
591         unsigned int len;
592         int rc, flags;
593
594         memset(&msg, 0, sizeof(msg));
595         msg.msg_iov = &iov;
596         msg.msg_iovlen = 1;
597
598         flags = MSG_PEEK;
599
600 retry:
601         iov.iov_len = network->netlink_buf_size;
602         iov.iov_base = network->netlink_buf;
603
604         rc = recvmsg(network->netlink_sd, &msg, flags);
605
606         if (rc < 0) {
607                 perror("netlink recv header");
608                 return -1;
609         }
610
611         len = rc;
612
613         /* if the netlink message was larger than our buffer, realloc
614          * before reading again */
615         if (len > network->netlink_buf_size || msg.msg_flags & MSG_TRUNC) {
616                 network->netlink_buf_size *= 2;
617                 network->netlink_buf = talloc_realloc(network,
618                                         network->netlink_buf,
619                                         char *,
620                                         network->netlink_buf_size);
621                 goto retry;
622         }
623
624         /* otherwise, we're good to read the entire message without PEEK */
625         if (flags == MSG_PEEK) {
626                 flags = 0;
627                 goto retry;
628         }
629
630         for_each_nlmsg(network->netlink_buf, nlmsg, len)
631                 network_handle_nlmsg(network, nlmsg);
632
633         return 0;
634 }
635
636 static void network_init_dns(struct network *network)
637 {
638         const struct config *config;
639         unsigned int i;
640         int rc, len;
641         bool modified;
642         char *buf;
643
644         if (network->dry_run)
645                 return;
646
647         config = config_get();
648         if (!config || !config->network.n_dns_servers)
649                 return;
650
651         rc = read_file(network, "/etc/resolv.conf", &buf, &len);
652
653         if (rc) {
654                 buf = talloc_strdup(network, "");
655                 len = 0;
656         }
657
658         modified = false;
659
660         for (i = 0; i < config->network.n_dns_servers; i++) {
661                 int dns_conf_len;
662                 char *dns_conf;
663
664                 dns_conf = talloc_asprintf(network, "nameserver %s\n",
665                                 config->network.dns_servers[i]);
666
667                 if (strstr(buf, dns_conf)) {
668                         talloc_free(dns_conf);
669                         continue;
670                 }
671
672                 dns_conf_len = strlen(dns_conf);
673                 buf = talloc_realloc(network, buf, char, len + dns_conf_len + 1);
674                 memcpy(buf + len, dns_conf, dns_conf_len);
675                 len += dns_conf_len;
676                 buf[len] = '\0';
677                 modified = true;
678
679                 talloc_free(dns_conf);
680         }
681
682         if (modified) {
683                 rc = replace_file("/etc/resolv.conf", buf, len);
684                 if (rc)
685                         pb_log("error replacing resolv.conf: %s\n",
686                                         strerror(errno));
687         }
688
689         talloc_free(buf);
690 }
691
692 struct network *network_init(struct device_handler *handler,
693                 struct waitset *waitset, bool dry_run)
694 {
695         struct network *network;
696         int rc;
697
698         network = talloc(handler, struct network);
699         list_init(&network->interfaces);
700         network->handler = handler;
701         network->dry_run = dry_run;
702         network->manual_config = config_get()->network.n_interfaces != 0;
703
704         network_init_dns(network);
705
706         rc = network_init_netlink(network);
707         if (rc)
708                 goto err;
709
710         network->waiter = waiter_register_io(waitset, network->netlink_sd,
711                         WAIT_IN, network_netlink_process, network);
712
713         if (!network->waiter)
714                 goto err;
715
716         rc = network_send_link_query(network);
717         if (rc)
718                 goto err;
719
720         return network;
721
722 err:
723         network_shutdown(network);
724         return NULL;
725 }
726
727 int network_shutdown(struct network *network)
728 {
729         struct interface *interface;
730
731         if (network->waiter)
732                 waiter_remove(network->waiter);
733
734         list_for_each_entry(&network->interfaces, interface, list) {
735                 if (interface->state == IFSTATE_IGNORED)
736                         continue;
737                 if (!strcmp(interface->name, "lo"))
738                         continue;
739                 interface_down(interface);
740         }
741
742         close(network->netlink_sd);
743         talloc_free(network);
744         return 0;
745 }