summaryrefslogtreecommitdiffstats
path: root/discover/pxe-parser.c
blob: 4aae8b14bf2eccf27cd209fd8870218e4345d2d6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379

#if defined(HAVE_CONFIG_H)
#include "config.h"
#endif
#include <stdlib.h>
#include <string.h>

#include <talloc/talloc.h>
#include <url/url.h>
#include <log/log.h>
#include <file/file.h>
#include <i18n/i18n.h>

#include "parser.h"
#include "parser-conf.h"
#include "parser-utils.h"
#include "resource.h"
#include "paths.h"
#include "event.h"
#include "user-event.h"
#include "network.h"

static const char *pxelinux_prefix = "pxelinux.cfg/";

struct pxe_parser_info {
	struct discover_boot_option *opt;
	const char *default_name;
};

static void pxe_finish(struct conf_context *conf)
{
	struct pxe_parser_info *info = conf->parser_info;
	if (info->opt)
		discover_context_add_boot_option(conf->dc, info->opt);
}

/* We need a slightly modified version of pb_url_join, to allow for the
 * pxelinux "::filename" syntax for absolute URLs
 */
static struct pb_url *pxe_url_join(void *ctx, const struct pb_url *url,
		const char *s)
{
	struct pb_url *new_url;
	int len;

	len = strlen(s);

	if (len > 2 && s[0] == ':' && s[1] == ':') {
		char *tmp;

		if (s[2] == '/') {
			/* ::/path -> /path */
			tmp = talloc_strdup(ctx, s+2);
		} else {
			/* ::path -> /path */
			tmp = talloc_strdup(ctx, s+1);
			tmp[0] = '/';
		}

		new_url = pb_url_join(ctx, url, tmp);

		talloc_free(tmp);

	} else {
		const char *tmp;
		/* strip leading slashes */
		for (tmp = s; *tmp == '/'; tmp++)
			;
		new_url = pb_url_join(ctx, url, tmp);
	}

	return new_url;
}

static void pxe_append_string(struct discover_boot_option *opt,
		const char *str)
{
	if (opt->option->boot_args)
		opt->option->boot_args = talloc_asprintf_append(
				opt->option->boot_args, " %s", str);
	else
		opt->option->boot_args = talloc_strdup(opt->option, str);
}

static char *pxe_sysappend_mac(void *ctx, uint8_t *mac)
{
	if (!mac)
		return NULL;

	return talloc_asprintf(ctx,
		"BOOTIF=01-%02x-%02x-%02x-%02x-%02x-%02x",
		mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
}

static void pxe_process_sysappend(struct discover_context *ctx,
		struct discover_boot_option *opt,
		unsigned long val)
{
	struct event *event = ctx->event;
	char *str = NULL;

	if (!event)
		return;

	if (val & 0x2) {
		uint8_t *mac = find_mac_by_name(ctx, ctx->network,
					event->device);
		str = pxe_sysappend_mac(ctx, mac);
		if (str) {
			pxe_append_string(opt, str);
			talloc_free(str);
		}
		val &= ~0x2;
	}

	if (val)
		pb_log("pxe: unsupported features requested in "
				"ipappend/sysappend: 0x%04lx", val);

}

static void pxe_process_pair(struct conf_context *ctx,
		const char *name, char *value)
{
	struct pxe_parser_info *parser_info = ctx->parser_info;
	struct discover_boot_option *opt = parser_info->opt;
	struct pb_url *url;

	/* quirk in the syslinux config format: initrd can be separated
	 * by an '=' */
	if (!name && !strncasecmp(value, "initrd=", strlen("initrd="))) {
		name = "initrd";
		value += strlen("initrd=");
	}

	if (!name)
		return;

	if (streq(name, "DEFAULT")) {
		parser_info->default_name = talloc_strdup(parser_info, value);
		return;
	}

	if (streq(name, "LABEL")) {
		if (opt)
			pxe_finish(ctx);

		opt = discover_boot_option_create(ctx->dc, ctx->dc->device);

		opt->option->name = talloc_strdup(opt, value);
		opt->option->id = talloc_asprintf(opt, "%s@%p",
				ctx->dc->device->device->id, opt);

		opt->option->is_default = parser_info->default_name &&
					streq(parser_info->default_name, value);

		parser_info->opt = opt;
		return;
	}

	/* all other parameters need an option */
	if (!opt)
		return;

	if (streq(name, "KERNEL")) {
		url = pxe_url_join(ctx->dc, ctx->dc->conf_url, value);
		opt->boot_image = create_url_resource(opt, url);

		char* args_sigfile_default = talloc_asprintf(opt,
			"%s.cmdline.sig", value);
		url = pxe_url_join(ctx->dc, ctx->dc->conf_url,
			args_sigfile_default);
		opt->args_sig_file = create_url_resource(opt, url);
		talloc_free(args_sigfile_default);

	} else if (streq(name, "INITRD")) {
		url = pxe_url_join(ctx->dc, ctx->dc->conf_url, value);
		opt->initrd = create_url_resource(opt, url);

	} else if (streq(name, "APPEND")) {
		char *str, *end;

		pxe_append_string(opt, value);

		str = strcasestr(value, "INITRD=");
		if (str) {
			str += strlen("INITRD=");
			end = strchrnul(str, ' ');
			*end = '\0';

			url = pxe_url_join(ctx->dc, ctx->dc->conf_url, str);
			opt->initrd = create_url_resource(opt, url);
		}
	} else if (streq(name, "SYSAPPEND") || streq(name, "IPAPPEND")) {
		unsigned long type;
		char *end;

		type = strtoul(value, &end, 10);
		if (end != value && !(*end))
			pxe_process_sysappend(ctx->dc, opt, type);

	} else if (streq(name, "DTB") || streq(name, "FDT")) {
		url = pxe_url_join(ctx->dc, ctx->dc->conf_url, value);
		opt->dtb = create_url_resource(opt, url);
	}

}

/*
 * Callback for asynchronous loads from pxe_parse()
 * @param result Result of load_url_async()
 * @param data   Pointer to associated conf_context
 */
static void pxe_conf_parse_cb(struct load_url_result *result, void *data)
{
	struct conf_context *conf = data;
	struct device_handler *handler;
	struct boot_status status = {0};
	char *buf = NULL;
	int len, rc;

	if (!data)
		return;

	if (!result || result->status != LOAD_OK) {
		talloc_free(conf);
		return;
	}

	rc = read_file(conf, result->local, &buf, &len);
	if (rc) {
		pb_log("Read failed during pxe callback for %s\n", result->local);
		goto out_clean;
	}

	conf_parse_buf(conf, buf, len);

	/* We may be called well after the original caller of iterate_parsers(),
	 * commit any new boot options ourselves */
	handler = talloc_parent(conf);
	device_handler_discover_context_commit(handler, conf->dc);

	status.type = BOOT_STATUS_INFO;
	/*
	 * TRANSLATORS: the format specifier in this string in an IP address,
	 * eg. 192.168.1.1
	 */
	status.message = talloc_asprintf(conf, _("pxe: parsed config for %s"),
					conf->dc->conf_url->host);
	device_handler_boot_status(handler, &status);

	talloc_free(buf);
out_clean:
	if (result->cleanup_local)
		unlink(result->local);
	talloc_free(conf);
}

/**
 * Return a new conf_context and increment the talloc reference count on
 * the discover_context struct.
 * @param  ctx  Parent talloc context
 * @param  orig Original discover_context
 * @return      Pointer to new conf_context
 */
static struct conf_context *copy_context(void *ctx, struct discover_context *dc)
{
	struct pxe_parser_info *info;
	struct conf_context *conf;

	conf = talloc_zero(ctx, struct conf_context);

	if (!conf)
		return NULL;

	conf->get_pair = conf_get_pair_space;
	conf->process_pair = pxe_process_pair;
	conf->finish = pxe_finish;
	info = talloc_zero(conf, struct pxe_parser_info);
	if (!info) {
		talloc_free(conf);
		return NULL;
	}
	conf->parser_info = info;

	/*
	 * The discover_context may be freed once pxe_parse() returns, but the
	 * callback will still need it. Take a reference so that that it will
	 * persist until the last callback completes.
	 */
	conf->dc = talloc_reference(conf, dc);

	return conf;
}

static int pxe_parse(struct discover_context *dc)
{
	struct pb_url *pxe_base_url, *url;
	char **pxe_conf_files, **filename;
	struct conf_context *conf = NULL;
	struct load_url_result *result;
	void *ctx = talloc_parent(dc);
	bool complete_url;

	/* Expects dhcp event parameters to support network boot */
	if (!dc->event)
		return -1;

	dc->conf_url = user_event_parse_conf_url(dc, dc->event, &complete_url);
	if (!dc->conf_url)
		return -1;

	/*
	 * Retrieving PXE configs over the network can take some time depending
	 * on factors such as slow network, malformed paths, bad DNS, and
	 * overzealous firewalls. Instead of blocking the discover server while
	 * we wait for these, spawn an asynchronous job for each URL we can
	 * parse and process the resulting files in a callback. A separate
	 * conf_context is created for each job.
	 */
	conf = copy_context(ctx, dc);
	if (!conf)
		return -1;

	if (complete_url) {
		/* we have a complete URL; use this and we're done. */
		result = load_url_async(conf->dc, conf->dc->conf_url,
					pxe_conf_parse_cb, conf);
		if (!result) {
			pb_log("load_url_async fails for %s\n",
					dc->conf_url->path);
			goto out_conf;
		}
	} else {
		pxe_conf_files = user_event_parse_conf_filenames(dc, dc->event);
		if (!pxe_conf_files)
			goto out_conf;

		pxe_base_url = pb_url_join(dc, dc->conf_url, pxelinux_prefix);
		if (!pxe_base_url)
			goto out_pxe_conf;

		for (filename = pxe_conf_files; *filename; filename++) {
			if (!conf) {
				conf = copy_context(ctx, dc);
			}
			url = pb_url_join(conf->dc, pxe_base_url, *filename);
			if (!url)
				continue;
			result = load_url_async(conf, url, pxe_conf_parse_cb,
						conf);
			if (!result) {
				pb_log("load_url_async fails for %s\n",
				       conf->dc->conf_url->path);
				talloc_free(conf);
			}
			/* conf now needed by callback, don't reuse */
			conf = NULL;
		}

		talloc_free(pxe_base_url);
		talloc_free(pxe_conf_files);
	}

	return 0;

out_pxe_conf:
	talloc_free(pxe_conf_files);
out_conf:
	talloc_free(conf);
	return -1;
}

static struct parser pxe_parser = {
	.name			= "pxe",
	.parse			= pxe_parse,
};

register_parser(pxe_parser);
OpenPOWER on IntegriCloud