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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001// SPDX-License-Identifier: GPL-2.0
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +09002#include "debug.h"
Arnaldo Carvalho de Melo7ed09582016-07-07 11:06:58 -03003#include "util.h"
Arnaldo Carvalho de Meloe7f01d12012-03-14 12:29:29 -03004#include <linux/kernel.h>
Arnaldo Carvalho de Meloa43783a2017-04-18 10:46:11 -03005#include <errno.h>
Ingo Molnar07800602009-04-20 15:00:56 +02006
Ingo Molnar07800602009-04-20 15:00:56 +02007/*
8 * Used as the default ->buf value, so that people can always assume
9 * buf is non NULL and ->buf is NUL terminated even for a freshly
10 * initialized strbuf.
11 */
12char strbuf_slopbuf[1];
13
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090014int strbuf_init(struct strbuf *sb, ssize_t hint)
Ingo Molnar07800602009-04-20 15:00:56 +020015{
16 sb->alloc = sb->len = 0;
17 sb->buf = strbuf_slopbuf;
18 if (hint)
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090019 return strbuf_grow(sb, hint);
20 return 0;
Ingo Molnar07800602009-04-20 15:00:56 +020021}
22
23void strbuf_release(struct strbuf *sb)
24{
25 if (sb->alloc) {
Arnaldo Carvalho de Melo74cf2492013-12-27 16:55:14 -030026 zfree(&sb->buf);
Ingo Molnar07800602009-04-20 15:00:56 +020027 strbuf_init(sb, 0);
28 }
29}
30
31char *strbuf_detach(struct strbuf *sb, size_t *sz)
32{
33 char *res = sb->alloc ? sb->buf : NULL;
34 if (sz)
35 *sz = sb->len;
36 strbuf_init(sb, 0);
37 return res;
38}
39
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090040int strbuf_grow(struct strbuf *sb, size_t extra)
Ingo Molnar07800602009-04-20 15:00:56 +020041{
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090042 char *buf;
43 size_t nr = sb->len + extra + 1;
44
45 if (nr < sb->alloc)
46 return 0;
47
48 if (nr <= sb->len)
49 return -E2BIG;
50
51 if (alloc_nr(sb->alloc) > nr)
52 nr = alloc_nr(sb->alloc);
53
54 /*
55 * Note that sb->buf == strbuf_slopbuf if sb->alloc == 0, and it is
56 * a static variable. Thus we have to avoid passing it to realloc.
57 */
58 buf = realloc(sb->alloc ? sb->buf : NULL, nr * sizeof(*buf));
59 if (!buf)
60 return -ENOMEM;
61
62 sb->buf = buf;
63 sb->alloc = nr;
64 return 0;
Ingo Molnar07800602009-04-20 15:00:56 +020065}
66
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090067int strbuf_addch(struct strbuf *sb, int c)
Arnaldo Carvalho de Melo07412082016-03-23 16:56:56 -030068{
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090069 int ret = strbuf_grow(sb, 1);
70 if (ret)
71 return ret;
72
Arnaldo Carvalho de Melo07412082016-03-23 16:56:56 -030073 sb->buf[sb->len++] = c;
74 sb->buf[sb->len] = '\0';
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090075 return 0;
Arnaldo Carvalho de Melo07412082016-03-23 16:56:56 -030076}
77
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090078int strbuf_add(struct strbuf *sb, const void *data, size_t len)
Ingo Molnar07800602009-04-20 15:00:56 +020079{
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090080 int ret = strbuf_grow(sb, len);
81 if (ret)
82 return ret;
83
Ingo Molnar07800602009-04-20 15:00:56 +020084 memcpy(sb->buf + sb->len, data, len);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090085 return strbuf_setlen(sb, sb->len + len);
Ingo Molnar07800602009-04-20 15:00:56 +020086}
87
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090088static int strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap)
Ingo Molnar07800602009-04-20 15:00:56 +020089{
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090090 int len, ret;
Namhyung Kimc7118362015-10-25 00:49:27 +090091 va_list ap_saved;
Ingo Molnar07800602009-04-20 15:00:56 +020092
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090093 if (!strbuf_avail(sb)) {
94 ret = strbuf_grow(sb, 64);
95 if (ret)
96 return ret;
97 }
Namhyung Kimc7118362015-10-25 00:49:27 +090098
99 va_copy(ap_saved, ap);
Namhyung Kimf787d952012-10-23 22:44:50 +0900100 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400101 if (len < 0) {
102 va_end(ap_saved);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900103 return len;
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400104 }
Ingo Molnar07800602009-04-20 15:00:56 +0200105 if (len > strbuf_avail(sb)) {
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900106 ret = strbuf_grow(sb, len);
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400107 if (ret) {
108 va_end(ap_saved);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900109 return ret;
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400110 }
Namhyung Kimc7118362015-10-25 00:49:27 +0900111 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved);
Ingo Molnar07800602009-04-20 15:00:56 +0200112 if (len > strbuf_avail(sb)) {
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900113 pr_debug("this should not happen, your vsnprintf is broken");
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400114 va_end(ap_saved);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900115 return -EINVAL;
Ingo Molnar07800602009-04-20 15:00:56 +0200116 }
117 }
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400118 va_end(ap_saved);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900119 return strbuf_setlen(sb, sb->len + len);
Ingo Molnar07800602009-04-20 15:00:56 +0200120}
121
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900122int strbuf_addf(struct strbuf *sb, const char *fmt, ...)
Namhyung Kimc7118362015-10-25 00:49:27 +0900123{
124 va_list ap;
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900125 int ret;
Namhyung Kimc7118362015-10-25 00:49:27 +0900126
127 va_start(ap, fmt);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900128 ret = strbuf_addv(sb, fmt, ap);
Namhyung Kimc7118362015-10-25 00:49:27 +0900129 va_end(ap);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900130 return ret;
Namhyung Kimc7118362015-10-25 00:49:27 +0900131}
132
Ingo Molnarf37a2912009-07-01 12:37:06 +0200133ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
Ingo Molnar07800602009-04-20 15:00:56 +0200134{
135 size_t oldlen = sb->len;
136 size_t oldalloc = sb->alloc;
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900137 int ret;
Ingo Molnar07800602009-04-20 15:00:56 +0200138
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900139 ret = strbuf_grow(sb, hint ? hint : 8192);
140 if (ret)
141 return ret;
142
Ingo Molnar07800602009-04-20 15:00:56 +0200143 for (;;) {
144 ssize_t cnt;
145
146 cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
147 if (cnt < 0) {
148 if (oldalloc == 0)
149 strbuf_release(sb);
150 else
151 strbuf_setlen(sb, oldlen);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900152 return cnt;
Ingo Molnar07800602009-04-20 15:00:56 +0200153 }
154 if (!cnt)
155 break;
156 sb->len += cnt;
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900157 ret = strbuf_grow(sb, 8192);
158 if (ret)
159 return ret;
Ingo Molnar07800602009-04-20 15:00:56 +0200160 }
161
162 sb->buf[sb->len] = '\0';
163 return sb->len - oldlen;
164}