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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 Meloe7f01d12012-03-14 12:29:29 -03003#include <linux/kernel.h>
Arnaldo Carvalho de Melo7f7c5362019-07-04 11:32:27 -03004#include <linux/zalloc.h>
Arnaldo Carvalho de Meloa43783a2017-04-18 10:46:11 -03005#include <errno.h>
Arnaldo Carvalho de Melo215a0d32019-07-04 11:21:24 -03006#include <stdlib.h>
Ingo Molnar07800602009-04-20 15:00:56 +02007
Ingo Molnar07800602009-04-20 15:00:56 +02008/*
9 * Used as the default ->buf value, so that people can always assume
10 * buf is non NULL and ->buf is NUL terminated even for a freshly
11 * initialized strbuf.
12 */
13char strbuf_slopbuf[1];
14
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090015int strbuf_init(struct strbuf *sb, ssize_t hint)
Ingo Molnar07800602009-04-20 15:00:56 +020016{
17 sb->alloc = sb->len = 0;
18 sb->buf = strbuf_slopbuf;
19 if (hint)
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090020 return strbuf_grow(sb, hint);
21 return 0;
Ingo Molnar07800602009-04-20 15:00:56 +020022}
23
24void strbuf_release(struct strbuf *sb)
25{
26 if (sb->alloc) {
Arnaldo Carvalho de Melo74cf2492013-12-27 16:55:14 -030027 zfree(&sb->buf);
Ingo Molnar07800602009-04-20 15:00:56 +020028 strbuf_init(sb, 0);
29 }
30}
31
32char *strbuf_detach(struct strbuf *sb, size_t *sz)
33{
34 char *res = sb->alloc ? sb->buf : NULL;
35 if (sz)
36 *sz = sb->len;
37 strbuf_init(sb, 0);
38 return res;
39}
40
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090041int strbuf_grow(struct strbuf *sb, size_t extra)
Ingo Molnar07800602009-04-20 15:00:56 +020042{
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090043 char *buf;
44 size_t nr = sb->len + extra + 1;
45
46 if (nr < sb->alloc)
47 return 0;
48
49 if (nr <= sb->len)
50 return -E2BIG;
51
52 if (alloc_nr(sb->alloc) > nr)
53 nr = alloc_nr(sb->alloc);
54
55 /*
56 * Note that sb->buf == strbuf_slopbuf if sb->alloc == 0, and it is
57 * a static variable. Thus we have to avoid passing it to realloc.
58 */
59 buf = realloc(sb->alloc ? sb->buf : NULL, nr * sizeof(*buf));
60 if (!buf)
61 return -ENOMEM;
62
63 sb->buf = buf;
64 sb->alloc = nr;
65 return 0;
Ingo Molnar07800602009-04-20 15:00:56 +020066}
67
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090068int strbuf_addch(struct strbuf *sb, int c)
Arnaldo Carvalho de Melo07412082016-03-23 16:56:56 -030069{
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090070 int ret = strbuf_grow(sb, 1);
71 if (ret)
72 return ret;
73
Arnaldo Carvalho de Melo07412082016-03-23 16:56:56 -030074 sb->buf[sb->len++] = c;
75 sb->buf[sb->len] = '\0';
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090076 return 0;
Arnaldo Carvalho de Melo07412082016-03-23 16:56:56 -030077}
78
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090079int strbuf_add(struct strbuf *sb, const void *data, size_t len)
Ingo Molnar07800602009-04-20 15:00:56 +020080{
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090081 int ret = strbuf_grow(sb, len);
82 if (ret)
83 return ret;
84
Ingo Molnar07800602009-04-20 15:00:56 +020085 memcpy(sb->buf + sb->len, data, len);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090086 return strbuf_setlen(sb, sb->len + len);
Ingo Molnar07800602009-04-20 15:00:56 +020087}
88
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090089static int strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap)
Ingo Molnar07800602009-04-20 15:00:56 +020090{
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090091 int len, ret;
Namhyung Kimc7118362015-10-25 00:49:27 +090092 va_list ap_saved;
Ingo Molnar07800602009-04-20 15:00:56 +020093
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +090094 if (!strbuf_avail(sb)) {
95 ret = strbuf_grow(sb, 64);
96 if (ret)
97 return ret;
98 }
Namhyung Kimc7118362015-10-25 00:49:27 +090099
100 va_copy(ap_saved, ap);
Namhyung Kimf787d952012-10-23 22:44:50 +0900101 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400102 if (len < 0) {
103 va_end(ap_saved);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900104 return len;
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400105 }
Ingo Molnar07800602009-04-20 15:00:56 +0200106 if (len > strbuf_avail(sb)) {
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900107 ret = strbuf_grow(sb, len);
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400108 if (ret) {
109 va_end(ap_saved);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900110 return ret;
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400111 }
Namhyung Kimc7118362015-10-25 00:49:27 +0900112 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved);
Ingo Molnar07800602009-04-20 15:00:56 +0200113 if (len > strbuf_avail(sb)) {
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900114 pr_debug("this should not happen, your vsnprintf is broken");
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400115 va_end(ap_saved);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900116 return -EINVAL;
Ingo Molnar07800602009-04-20 15:00:56 +0200117 }
118 }
Sanskriti Sharmace49d842018-10-02 10:29:10 -0400119 va_end(ap_saved);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900120 return strbuf_setlen(sb, sb->len + len);
Ingo Molnar07800602009-04-20 15:00:56 +0200121}
122
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900123int strbuf_addf(struct strbuf *sb, const char *fmt, ...)
Namhyung Kimc7118362015-10-25 00:49:27 +0900124{
125 va_list ap;
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900126 int ret;
Namhyung Kimc7118362015-10-25 00:49:27 +0900127
128 va_start(ap, fmt);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900129 ret = strbuf_addv(sb, fmt, ap);
Namhyung Kimc7118362015-10-25 00:49:27 +0900130 va_end(ap);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900131 return ret;
Namhyung Kimc7118362015-10-25 00:49:27 +0900132}
133
Ingo Molnarf37a2912009-07-01 12:37:06 +0200134ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
Ingo Molnar07800602009-04-20 15:00:56 +0200135{
136 size_t oldlen = sb->len;
137 size_t oldalloc = sb->alloc;
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900138 int ret;
Ingo Molnar07800602009-04-20 15:00:56 +0200139
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900140 ret = strbuf_grow(sb, hint ? hint : 8192);
141 if (ret)
142 return ret;
143
Ingo Molnar07800602009-04-20 15:00:56 +0200144 for (;;) {
145 ssize_t cnt;
146
147 cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
148 if (cnt < 0) {
149 if (oldalloc == 0)
150 strbuf_release(sb);
151 else
152 strbuf_setlen(sb, oldlen);
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900153 return cnt;
Ingo Molnar07800602009-04-20 15:00:56 +0200154 }
155 if (!cnt)
156 break;
157 sb->len += cnt;
Masami Hiramatsu5cea57f2016-05-10 14:46:58 +0900158 ret = strbuf_grow(sb, 8192);
159 if (ret)
160 return ret;
Ingo Molnar07800602009-04-20 15:00:56 +0200161 }
162
163 sb->buf[sb->len] = '\0';
164 return sb->len - oldlen;
165}