hast_proto.c revision 207070 
1/*-
2 * Copyright (c) 2009-2010 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Pawel Jakub Dawidek under sponsorship from
6 * the FreeBSD Foundation.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: head/sbin/hastd/hast_proto.c 207070 2010-04-22 19:18:10Z pjd $");
32
33#include <sys/endian.h>
34
35#include <assert.h>
36#include <errno.h>
37#include <string.h>
38#include <strings.h>
39
40#ifdef HAVE_CRYPTO
41#include <openssl/sha.h>
42#endif
43
44#include <hast.h>
45#include <ebuf.h>
46#include <nv.h>
47#include <pjdlog.h>
48#include <proto.h>
49
50#include "hast_proto.h"
51
52struct hast_main_header {
53	/* Protocol version. */
54	uint8_t		version;
55	/* Size of nv headers. */
56	uint32_t	size;
57} __packed;
58
59typedef int hps_send_t(struct hast_resource *, struct nv *nv, void **, size_t *, bool *);
60typedef int hps_recv_t(struct hast_resource *, struct nv *nv, void **, size_t *, bool *);
61
62struct hast_pipe_stage {
63	const char	*hps_name;
64	hps_send_t	*hps_send;
65	hps_recv_t	*hps_recv;
66};
67
68static int compression_send(struct hast_resource *res, struct nv *nv,
69    void **datap, size_t *sizep, bool *freedatap);
70static int compression_recv(struct hast_resource *res, struct nv *nv,
71    void **datap, size_t *sizep, bool *freedatap);
72#ifdef HAVE_CRYPTO
73static int checksum_send(struct hast_resource *res, struct nv *nv,
74    void **datap, size_t *sizep, bool *freedatap);
75static int checksum_recv(struct hast_resource *res, struct nv *nv,
76    void **datap, size_t *sizep, bool *freedatap);
77#endif
78
79static struct hast_pipe_stage pipeline[] = {
80	{ "compression", compression_send, compression_recv },
81#ifdef HAVE_CRYPTO
82	{ "checksum", checksum_send, checksum_recv }
83#endif
84};
85
86static int
87compression_send(struct hast_resource *res, struct nv *nv, void **datap,
88    size_t *sizep, bool *freedatap)
89{
90	unsigned char *newbuf;
91
92	res = res;	/* TODO */
93
94	/*
95	 * TODO: For now we emulate compression.
96	 * At 80% probability we succeed to compress data, which means we
97	 * allocate new buffer, copy the data over set *freedatap to true.
98	 */
99
100	if (arc4random_uniform(100) < 80) {
101		uint32_t *origsize;
102
103		/*
104		 * Compression succeeded (but we will grow by 4 bytes, not
105		 * shrink for now).
106		 */
107		newbuf = malloc(sizeof(uint32_t) + *sizep);
108		if (newbuf == NULL)
109			return (-1);
110		origsize = (void *)newbuf;
111		*origsize = htole32((uint32_t)*sizep);
112		nv_add_string(nv, "null", "compression");
113		if (nv_error(nv) != 0) {
114			free(newbuf);
115			errno = nv_error(nv);
116			return (-1);
117		}
118		bcopy(*datap, newbuf + sizeof(uint32_t), *sizep);
119		if (*freedatap)
120			free(*datap);
121		*freedatap = true;
122		*datap = newbuf;
123		*sizep = sizeof(uint32_t) + *sizep;
124	} else {
125		/*
126		 * Compression failed, so we leave everything as it was.
127		 * It is not critical for compression to succeed.
128		 */
129	}
130
131	return (0);
132}
133
134static int
135compression_recv(struct hast_resource *res, struct nv *nv, void **datap,
136    size_t *sizep, bool *freedatap)
137{
138	unsigned char *newbuf;
139	const char *algo;
140	size_t origsize;
141
142	res = res;	/* TODO */
143
144	/*
145	 * TODO: For now we emulate compression.
146	 */
147
148	algo = nv_get_string(nv, "compression");
149	if (algo == NULL)
150		return (0);	/* No compression. */
151	if (strcmp(algo, "null") != 0) {
152		pjdlog_error("Unknown compression algorithm '%s'.", algo);
153		return (-1);	/* Unknown compression algorithm. */
154	}
155
156	origsize = le32toh(*(uint32_t *)*datap);
157	newbuf = malloc(origsize);
158	if (newbuf == NULL)
159		return (-1);
160	bcopy((unsigned char *)*datap + sizeof(uint32_t), newbuf, origsize);
161	if (*freedatap)
162		free(*datap);
163	*freedatap = true;
164	*datap = newbuf;
165	*sizep = origsize;
166
167	return (0);
168}
169
170#ifdef HAVE_CRYPTO
171static int
172checksum_send(struct hast_resource *res, struct nv *nv, void **datap,
173    size_t *sizep, bool *freedatap __unused)
174{
175	unsigned char hash[SHA256_DIGEST_LENGTH];
176	SHA256_CTX ctx;
177
178	res = res;	/* TODO */
179
180	SHA256_Init(&ctx);
181	SHA256_Update(&ctx, *datap, *sizep);
182	SHA256_Final(hash, &ctx);
183
184	nv_add_string(nv, "sha256", "checksum");
185	nv_add_uint8_array(nv, hash, sizeof(hash), "hash");
186
187	return (0);
188}
189
190static int
191checksum_recv(struct hast_resource *res, struct nv *nv, void **datap,
192    size_t *sizep, bool *freedatap __unused)
193{
194	unsigned char chash[SHA256_DIGEST_LENGTH];
195	const unsigned char *rhash;
196	SHA256_CTX ctx;
197	const char *algo;
198	size_t size;
199
200	res = res;	/* TODO */
201
202	algo = nv_get_string(nv, "checksum");
203	if (algo == NULL)
204		return (0);	/* No checksum. */
205	if (strcmp(algo, "sha256") != 0) {
206		pjdlog_error("Unknown checksum algorithm '%s'.", algo);
207		return (-1);	/* Unknown checksum algorithm. */
208	}
209	rhash = nv_get_uint8_array(nv, &size, "hash");
210	if (rhash == NULL) {
211		pjdlog_error("Checksum algorithm is present, but hash is missing.");
212		return (-1);	/* Hash not found. */
213	}
214	if (size != sizeof(chash)) {
215		pjdlog_error("Invalid hash size (%zu) for %s, should be %zu.",
216		    size, algo, sizeof(chash));
217		return (-1);	/* Different hash size. */
218	}
219
220	SHA256_Init(&ctx);
221	SHA256_Update(&ctx, *datap, *sizep);
222	SHA256_Final(chash, &ctx);
223
224	if (bcmp(rhash, chash, sizeof(chash)) != 0) {
225		pjdlog_error("Hash mismatch.");
226		return (-1);	/* Hash mismatch. */
227	}
228
229	return (0);
230}
231#endif	/* HAVE_CRYPTO */
232
233/*
234 * Send the given nv structure via conn.
235 * We keep headers in nv structure and pass data in separate argument.
236 * There can be no data at all (data is NULL then).
237 */
238int
239hast_proto_send(struct hast_resource *res, struct proto_conn *conn,
240    struct nv *nv, const void *data, size_t size)
241{
242	struct hast_main_header hdr;
243	struct ebuf *eb;
244	bool freedata;
245	void *dptr, *hptr;
246	size_t hsize;
247	int ret;
248
249	dptr = (void *)(uintptr_t)data;
250	freedata = false;
251	ret = -1;
252
253	if (data != NULL) {
254if (false) {
255		unsigned int ii;
256
257		for (ii = 0; ii < sizeof(pipeline) / sizeof(pipeline[0]);
258		    ii++) {
259			ret = pipeline[ii].hps_send(res, nv, &dptr, &size,
260			    &freedata);
261			if (ret == -1)
262				goto end;
263		}
264		ret = -1;
265}
266		nv_add_uint32(nv, size, "size");
267		if (nv_error(nv) != 0) {
268			errno = nv_error(nv);
269			goto end;
270		}
271	}
272
273	eb = nv_hton(nv);
274	if (eb == NULL)
275		goto end;
276
277	hdr.version = HAST_PROTO_VERSION;
278	hdr.size = htole32((uint32_t)ebuf_size(eb));
279	if (ebuf_add_head(eb, &hdr, sizeof(hdr)) < 0)
280		goto end;
281
282	hptr = ebuf_data(eb, &hsize);
283	if (proto_send(conn, hptr, hsize) < 0)
284		goto end;
285	if (data != NULL && proto_send(conn, dptr, size) < 0)
286		goto end;
287
288	ret = 0;
289end:
290	if (freedata)
291		free(dptr);
292	return (ret);
293}
294
295int
296hast_proto_recv_hdr(struct proto_conn *conn, struct nv **nvp)
297{
298	struct hast_main_header hdr;
299	struct nv *nv;
300	struct ebuf *eb;
301	void *hptr;
302
303	eb = NULL;
304	nv = NULL;
305
306	if (proto_recv(conn, &hdr, sizeof(hdr)) < 0)
307		goto fail;
308
309	if (hdr.version != HAST_PROTO_VERSION) {
310		errno = ERPCMISMATCH;
311		goto fail;
312	}
313
314	hdr.size = le32toh(hdr.size);
315
316	eb = ebuf_alloc(hdr.size);
317	if (eb == NULL)
318		goto fail;
319	if (ebuf_add_tail(eb, NULL, hdr.size) < 0)
320		goto fail;
321	hptr = ebuf_data(eb, NULL);
322	assert(hptr != NULL);
323	if (proto_recv(conn, hptr, hdr.size) < 0)
324		goto fail;
325	nv = nv_ntoh(eb);
326	if (nv == NULL)
327		goto fail;
328
329	*nvp = nv;
330	return (0);
331fail:
332	if (nv != NULL)
333		nv_free(nv);
334	else if (eb != NULL)
335		ebuf_free(eb);
336	return (-1);
337}
338
339int
340hast_proto_recv_data(struct hast_resource *res, struct proto_conn *conn,
341    struct nv *nv, void *data, size_t size)
342{
343	unsigned int ii;
344	bool freedata;
345	size_t dsize;
346	void *dptr;
347	int ret;
348
349	assert(data != NULL);
350	assert(size > 0);
351
352	ret = -1;
353	freedata = false;
354	dptr = data;
355
356	dsize = nv_get_uint32(nv, "size");
357	if (dsize == 0)
358		(void)nv_set_error(nv, 0);
359	else {
360		if (proto_recv(conn, data, dsize) < 0)
361			goto end;
362if (false) {
363		for (ii = sizeof(pipeline) / sizeof(pipeline[0]); ii > 0;
364		    ii--) {
365			assert(!"to be verified");
366			ret = pipeline[ii - 1].hps_recv(res, nv, &dptr,
367			    &dsize, &freedata);
368			if (ret == -1)
369				goto end;
370		}
371		ret = -1;
372		if (dsize < size)
373			goto end;
374		/* TODO: 'size' doesn't seem right here. It is maximum data size. */
375		if (dptr != data)
376			bcopy(dptr, data, dsize);
377}
378	}
379
380	ret = 0;
381end:
382if (ret < 0) printf("%s:%u %s\n", __func__, __LINE__, strerror(errno));
383	if (freedata)
384		free(dptr);
385	return (ret);
386}
387
388int
389hast_proto_recv(struct hast_resource *res, struct proto_conn *conn,
390    struct nv **nvp, void *data, size_t size)
391{
392	struct nv *nv;
393	size_t dsize;
394	int ret;
395
396	ret = hast_proto_recv_hdr(conn, &nv);
397	if (ret < 0)
398		return (ret);
399	dsize = nv_get_uint32(nv, "size");
400	if (dsize == 0)
401		(void)nv_set_error(nv, 0);
402	else
403		ret = hast_proto_recv_data(res, conn, nv, data, size);
404	if (ret < 0)
405		nv_free(nv);
406	else
407		*nvp = nv;
408	return (ret);
409}
410