summaryrefslogtreecommitdiffhomepage
path: root/src/driver/mdso_unit_ctx.c
blob: 807e80ea5461006d63baebfb7e4466c292d94646 (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
/****************************************************************/
/*  mdso: midipix dso scavenger                                 */
/*  Copyright (C) 2015  Z. Gilboa                               */
/*  Released under GPLv2 and GPLv3; see COPYING.MDSO.           */
/****************************************************************/

#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/mman.h>

#include <mdso/mdso.h>
#include "mdso_driver_impl.h"

static int mdso_free_unit_ctx_impl(struct mdso_unit_ctx_impl * ctx, int status)
{
	if (ctx) {
		if (ctx->expsyms && ctx->expsyms->buffer)
			free(ctx->expsyms->buffer);

		if (ctx->expsyms)
			free(ctx->expsyms);

		mdso_unmap_input(&ctx->map);
		free(ctx);
	}

	return status;
}

static FILE * mdso_stdin_to_tmp(const struct mdso_driver_ctx * dctx)
{
	struct mdso_driver_ctx_impl *	ictx;
	uintptr_t			addr;
	int				fdtmp;

	FILE *	ftmp;
	char	buf[4096];
	ssize_t	nread;
	int	ret;

	addr = (uintptr_t)dctx - offsetof(struct mdso_driver_ctx_impl,ctx);
	ictx = (struct mdso_driver_ctx_impl *)addr;

	if (ictx->fdtmpin >= 0) {
		if ((fdtmp = dup(ictx->fdtmpin)) < 0)
			return 0;

		if (!(ftmp = fdopen(fdtmp,"r")))
			close(fdtmp);

		return ftmp;
	}

	if (!(ftmp = tmpfile()))
		return 0;

	if ((ictx->fdtmpin = dup(fileno(ftmp))) < 0) {
		fclose(ftmp);
		return 0;
	}

	nread = read(0,buf,sizeof(buf)-1);

	while (nread) {
		if (nread > 0) {
			buf[nread] = '\0';
			ret = fputs(buf,ftmp);
		} else
			ret = (errno == EINTR) ? 0 : -1;

		if (ret < 0) {
			fclose(ftmp);
			return 0;
		}

		nread = read(0,buf,sizeof(buf)-1);
	}

	return ftmp;
}

static int mdso_create_symbol_vector(struct mdso_unit_ctx_impl * ctx)
{
	int		nsyms;
	size_t		nbytes;
	size_t		size;
	char *		dst;
	const char *	ch;
	const char **	sym;

	const char	exphdr[] = "EXPORTS\n";
	const char	imphdr[] = "IMPORTS\n";

	ch	= ctx->map.addr;
	nbytes	= ctx->map.size;

	for (nsyms=0; nbytes; ch++,nbytes--)
		nsyms += (*ch == '\n');

	size = offsetof(struct mdso_unit_ctx_impl,expsyms);
	size += (nsyms+1)*sizeof(const char *);

	if (!(ctx->expsyms = calloc(1,size)))
		return -1;

	if (!(ctx->expsyms->buffer = calloc(1,ctx->map.size)))
		return -1;

	ch	= ctx->map.addr;
	nbytes	= ctx->map.size;
	sym	= ctx->expsyms->syms;
	dst	= ctx->expsyms->buffer;
	size	= strlen(exphdr);

	/* support .def input files */
	if ((nbytes >= size) && !(strncmp(ch,exphdr,size))) {
		ch	+= size;
		nbytes	-= size;
	}

	/* advance to first symbol */
	for (; nbytes && ((*ch==' ')
			|| (*ch=='\t')
			|| (*ch=='\r')
			|| (*ch=='\n')); nbytes--)
		ch++;

	/* support .def input files */
	size = strlen(imphdr);

	while (nbytes && ((nbytes < size) || (strncmp(ch,imphdr,size)))) {
		/* vector */
		*sym++ = dst;

		/* symbol */
		for (; nbytes && ((*ch!=' ')
				&& (*ch!='\t')
				&& (*ch!='\r')
				&& (*ch!='\n')); nbytes--)
			*dst++ = *ch++;

		dst++;

		/* discard rest of input line */
		for (; nbytes && (*ch!='\n'); nbytes--)
			ch++;

		/* advance to next symbol */
		for (; nbytes && ((*ch==' ')
				|| (*ch=='\t')
				|| (*ch=='\r')
				|| (*ch=='\n')); nbytes--)
			ch++;
	}

	return 0;
}

int mdso_get_unit_ctx(
	const struct mdso_driver_ctx *	dctx,
	const char *			path,
	struct mdso_unit_ctx **		pctx)
{
	struct mdso_unit_ctx_impl *	ctx;
	FILE *				ftmp;
	int				fd;

	if (!dctx || !(ctx = calloc(1,sizeof(*ctx))))
		return -1;

	if (strcmp(path,"-"))
		fd = -1;
	else if (!(ftmp = mdso_stdin_to_tmp(dctx)))
		return mdso_free_unit_ctx_impl(ctx,-1);
	else if ((fd = dup(fileno(ftmp))) < 0)
		return mdso_free_unit_ctx_impl(ctx,-1);
	else
		fclose(ftmp);

	if (mdso_map_input(fd,path,PROT_READ,&ctx->map))
		return mdso_free_unit_ctx_impl(ctx,-1);

	if (fd > 0)
		close(fd);

	if (mdso_create_symbol_vector(ctx))
		return mdso_free_unit_ctx_impl(ctx,-1);

	memcpy(&ctx->cctx,dctx->cctx,
		sizeof(ctx->cctx));

	ctx->path	= path;

	ctx->uctx.path	= &ctx->path;
	ctx->uctx.map	= &ctx->map;
	ctx->uctx.cctx	= &ctx->cctx;
	ctx->uctx.syms	= ctx->expsyms->syms;

	*pctx = &ctx->uctx;
	return 0;
}

void mdso_free_unit_ctx(struct mdso_unit_ctx * ctx)
{
	struct mdso_unit_ctx_impl *	ictx;
	uintptr_t			addr;

	if (ctx) {
		addr = (uintptr_t)ctx - offsetof(struct mdso_unit_ctx_impl,uctx);
		ictx = (struct mdso_unit_ctx_impl *)addr;
		mdso_free_unit_ctx_impl(ictx,0);
	}
}