summaryrefslogtreecommitdiff
path: root/src/logic/tpax_archive_append.c
blob: caa2606dd3cd1119cfe13f61c353877b2a89310f (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
/******************************************************/
/*  tpax: a topological pax implementation            */
/*  Copyright (C) 2020  Z. Gilboa                     */
/*  Released under GPLv2 and GPLv3; see COPYING.TPAX. */
/******************************************************/

#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <grp.h>
#include <pwd.h>
#include <sys/stat.h>

#include <tpax/tpax.h>
#include <tpax/tpax_specs.h>
#include "tpax_driver_impl.h"
#include "tpax_tmpfile_impl.h"
#include "tpax_errinfo_impl.h"

#ifndef ssizeof
#define ssizeof(x) (ssize_t)(sizeof(x))
#endif

static int tpax_archive_append_memory_data(
	int                             fdout,
	void *                          buf,
	ssize_t                         nbytes)
{
	ssize_t ret;
	char  * ch;

	for (ch=buf; nbytes; ch+=ret) {
		ret = write(fdout,ch,nbytes);

		while ((ret < 0) && (errno == EINTR))
			ret = write(fdout,ch,nbytes);

		if (ret < 0)
			return ret;

		nbytes -= ret;
	}

	return 0;
}

static int tpax_archive_append_pad(
	const struct tpax_driver_ctx *  dctx,
	int                             fdout,
	const struct stat *             st)
{
	int     ret;
	off_t   cpos;
	ssize_t nbytes;
	char    buf[512];

	nbytes  = st->st_size;
	nbytes += 0x1ff;
	nbytes |= 0x1ff;
	nbytes ^= 0x1ff;
	nbytes -= st->st_size;

	memset(buf,0,nbytes);

	cpos  = tpax_get_driver_cpos(dctx);
	cpos += st->st_size + nbytes;

	if (!(ret = tpax_archive_append_memory_data(fdout,buf,nbytes)))
		tpax_set_driver_cpos(dctx,cpos);

	return ret;
}

int tpax_archive_append(
	const struct tpax_driver_ctx *  dctx,
	const struct tpax_unit_ctx *    uctx)
{
	struct tpax_ustar_header        uhdr;
	off_t                           hpos;
	off_t                           dpos;
	int                             fdout;
	int                             fdtmp;
	ssize_t                         nread;
	ssize_t                         nbytes;
	void *                          buf;
	size_t                          buflen;
	size_t                          cmplen;
	void *				membuf;
	char                            sbuf[2048];

	/* record errors */
	tpax_driver_set_ectx(
		dctx,0,
		*uctx->path);

	/* driver */
	fdout = tpax_driver_fdout(dctx);

	/* header and data offsets: todo pax and cpio */
	hpos = tpax_get_driver_cpos(dctx);
	dpos = hpos + sizeof(uhdr);

	/* header */
	if (tpax_init_ustar_header(
			dctx,*uctx->path,uctx->st,
			*uctx->link,&uhdr) < 0)
		return TPAX_NESTED_ERROR(dctx);

	/* buffer  */
	membuf = 0;
	fdtmp  = -1;

	/* associated data? */
	if S_ISREG(uctx->st->st_mode) {
		if ((buf = tpax_get_driver_anon_map_addr(dctx,&buflen)))
			if (buflen >= (cmplen = uctx->st->st_size))
				membuf = buf;

		if (ssizeof(sbuf) >= (uctx->st->st_size))
			membuf = sbuf;

		/* snapshot */
		if (membuf) {
			if (tpax_file_create_memory_snapshot(
					dctx,*uctx->path,
					uctx->st,membuf) < 0)
				return TPAX_NESTED_ERROR(dctx);
		} else {
			if ((fdtmp = tpax_file_create_tmpfs_snapshot(
					dctx,*uctx->path,
					uctx->st)) < 0)
				return TPAX_NESTED_ERROR(dctx);

			if (lseek(fdtmp,0,SEEK_SET) < 0)
				return TPAX_SYSTEM_ERROR(dctx);
		}
	}

	/* append header */
	if (tpax_archive_append_memory_data(fdout,&uhdr,ssizeof(uhdr)) < 0) {
		if (fdtmp >= 0)
			close(fdtmp);

		return TPAX_SYSTEM_ERROR(dctx);
	}

	tpax_set_driver_cpos(dctx,dpos);

	/* all done? */
	if (!(S_ISREG(uctx->st->st_mode)))
		return 0;

	/* append data from snapshot */
	if (fdtmp >= 0) {
		if (!buf) {
			buf    = sbuf;
			buflen = sizeof(sbuf);
		}

		for (nread=0; nread<uctx->st->st_size; ) {
			nbytes = read(fdtmp,buf,buflen);

			while ((nbytes < 0) && (errno == EINTR))
				nbytes = read(fdtmp,buf,buflen);

			if (nbytes < 0) {
				close(fdtmp);
				return TPAX_SYSTEM_ERROR(dctx);

			} else if (nbytes == 0) {
				close(fdtmp);
				return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FLOW_ERROR);

			} else {
				nread += nbytes;
			}

			if (tpax_archive_append_memory_data(fdout,buf,nbytes) < 0) {
				close(fdtmp);
				return TPAX_SYSTEM_ERROR(dctx);
			}
		}

		close(fdtmp);
	} else {
		if (tpax_archive_append_memory_data(
				fdout,membuf,
				uctx->st->st_size) < 0)
			return TPAX_SYSTEM_ERROR(dctx);
	}

	return tpax_archive_append_pad(
		dctx,fdout,uctx->st);
}

int tpax_archive_seal(const struct tpax_driver_ctx * dctx)
{
	int     fdout;
	off_t   cpos;
	ssize_t nbytes;
	ssize_t nwritten;
	ssize_t blksize;
	char    buf[512];

	blksize = tpax_get_archive_block_size(dctx);
	cpos    = tpax_get_driver_cpos(dctx);

	if (cpos % 512)
		return TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FLOW_ERROR);

	fdout = tpax_driver_fdout(dctx);
	memset(buf,0,sizeof(buf));

	switch (cpos % blksize) {
		case 0:
			nbytes = cpos + blksize;
			break;

		default:
			nbytes  = cpos / blksize;
			nbytes *= blksize;
			nbytes += blksize;

			if (nbytes-cpos == 512)
				nbytes += blksize;
	}

	for (nwritten=cpos; nwritten<nbytes; nwritten+=512) {
		if (tpax_archive_append_memory_data(fdout,buf,512) < 0)
			return TPAX_SYSTEM_ERROR(dctx);

		tpax_set_driver_cpos(dctx,nwritten);
	}

	return 0;
}