xref: /freebsd/contrib/elftoolchain/libpe/libpe_buffer.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1 /*-
2  * Copyright (c) 2016 Kai Wang
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/param.h>
28 #include <assert.h>
29 #include <errno.h>
30 #include <stdlib.h>
31 #include <unistd.h>
32 
33 #include "_libpe.h"
34 
35 ELFTC_VCSID("$Id: libpe_buffer.c 3312 2016-01-10 09:23:51Z kaiwang27 $");
36 
37 PE_SecBuf *
38 libpe_alloc_buffer(PE_Scn *ps, size_t sz)
39 {
40 	PE_SecBuf *sb;
41 
42 	if ((sb = malloc(sizeof(PE_SecBuf))) == NULL) {
43 		errno = ENOMEM;
44 		return (NULL);
45 	}
46 
47 	sb->sb_ps = ps;
48 	sb->sb_flags = 0;
49 	sb->sb_pb.pb_align = 1;
50 	sb->sb_pb.pb_off = 0;
51 	sb->sb_pb.pb_size = sz;
52 	if (sz > 0) {
53 		if ((sb->sb_pb.pb_buf = malloc(sz)) == NULL) {
54 			free(sb);
55 			errno = ENOMEM;
56 			return (NULL);
57 		}
58 		sb->sb_flags |= LIBPE_F_BUFFER_MALLOCED;
59 	} else
60 		sb->sb_pb.pb_buf = NULL;
61 
62 	STAILQ_INSERT_TAIL(&ps->ps_b, sb, sb_next);
63 
64 	return (sb);
65 }
66 
67 void
68 libpe_release_buffer(PE_SecBuf *sb)
69 {
70 	PE_Scn *ps;
71 
72 	assert(sb != NULL);
73 
74 	ps = sb->sb_ps;
75 
76 	STAILQ_REMOVE(&ps->ps_b, sb, _PE_SecBuf, sb_next);
77 
78 	if (sb->sb_flags & LIBPE_F_BUFFER_MALLOCED)
79 		free(sb->sb_pb.pb_buf);
80 
81 	free(sb);
82 }
83 
84 static int
85 cmp_sb(PE_SecBuf *a, PE_SecBuf *b)
86 {
87 
88 	if (a->sb_pb.pb_off < b->sb_pb.pb_off)
89 		return (-1);
90 	else if (a->sb_pb.pb_off == b->sb_pb.pb_off)
91 		return (0);
92 	else
93 		return (1);
94 }
95 
96 static void
97 sort_buffers(PE_Scn *ps)
98 {
99 
100 	if (STAILQ_EMPTY(&ps->ps_b))
101 		return;
102 
103 	STAILQ_SORT(&ps->ps_b, _PE_SecBuf, sb_next, cmp_sb);
104 }
105 
106 size_t
107 libpe_resync_buffers(PE_Scn *ps)
108 {
109 	PE_SecBuf *sb;
110 	PE_Buffer *pb;
111 	size_t sz;
112 
113 	assert(ps->ps_flags & LIBPE_F_LOAD_SECTION);
114 
115 	sort_buffers(ps);
116 
117 	sz = 0;
118 	STAILQ_FOREACH(sb, &ps->ps_b, sb_next) {
119 		if (ps->ps_flags & PE_F_DIRTY)
120 			sb->sb_flags |= PE_F_DIRTY;
121 
122 		pb = (PE_Buffer *) sb;
123 		if (pb->pb_align > ps->ps_falign)
124 			pb->pb_align = ps->ps_falign;
125 		if (pb->pb_buf == NULL || pb->pb_size == 0)
126 			continue;
127 
128 		sz = roundup(sz, pb->pb_align);
129 
130 		if (pb->pb_off != (off_t) sz) {
131 			pb->pb_off = sz;
132 			sb->sb_flags |= PE_F_DIRTY;
133 		}
134 		sz += pb->pb_size;
135 	}
136 
137 	return (sz);
138 }
139 
140 int
141 libpe_write_buffers(PE_Scn *ps)
142 {
143 	PE *pe;
144 	PE_SecBuf *sb;
145 	PE_Buffer *pb;
146 	off_t off;
147 
148 	assert(ps->ps_flags & LIBPE_F_LOAD_SECTION);
149 
150 	pe = ps->ps_pe;
151 
152 	off = 0;
153 	STAILQ_FOREACH(sb, &ps->ps_b, sb_next) {
154 		pb = &sb->sb_pb;
155 		if (pb->pb_buf == NULL || pb->pb_size == 0)
156 			continue;
157 
158 		if ((sb->sb_flags & PE_F_DIRTY) == 0) {
159 			assert((pe->pe_flags & LIBPE_F_SPECIAL_FILE) == 0);
160 			if (lseek(pe->pe_fd, (off_t) pb->pb_size, SEEK_CUR) <
161 			    0) {
162 				errno = EIO;
163 				return (-1);
164 			}
165 			goto next_buf;
166 		}
167 
168 		if (pb->pb_off > off) {
169 			if (libpe_pad(pe, pb->pb_off - off) < 0)
170 				return (-1);
171 			off = pb->pb_off;
172 		}
173 
174 		if (write(pe->pe_fd, pb->pb_buf, pb->pb_size) !=
175 		    (ssize_t) pb->pb_size) {
176 			errno = EIO;
177 			return (-1);
178 		}
179 
180 	next_buf:
181 		off += pb->pb_size;
182 	}
183 
184 	return (0);
185 }
186