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Commit | Line | Data |
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7126d8c2 AK |
1 | /* |
2 | * Copyright (C) 2011-2012 Red Hat, Inc. | |
3 | * | |
4 | * This file is part of LVM2. | |
5 | * | |
6 | * This copyrighted material is made available to anyone wishing to use, | |
7 | * modify, copy, or redistribute it subject to the terms and conditions | |
8 | * of the GNU Lesser General Public License v.2.1. | |
9 | * | |
10 | * You should have received a copy of the GNU Lesser General Public License | |
11 | * along with this program; if not, write to the Free Software Foundation, | |
12 | * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
13 | */ | |
14 | ||
92658f56 PR |
15 | #include <errno.h> |
16 | #include <stdio.h> | |
17 | #include <malloc.h> | |
18 | #include <string.h> | |
6e4e3082 | 19 | #include <unistd.h> |
aac236f4 | 20 | #include <assert.h> |
7126d8c2 | 21 | |
4fcbeed6 | 22 | #include "daemon-shared.h" |
7126d8c2 | 23 | #include "libdevmapper.h" |
92658f56 PR |
24 | |
25 | /* | |
26 | * Read a single message from a (socket) filedescriptor. Messages are delimited | |
27 | * by blank lines. This call will block until all of a message is received. The | |
28 | * memory will be allocated from heap. Upon error, all memory is freed and the | |
29 | * buffer pointer is set to NULL. | |
4fcbeed6 PR |
30 | * |
31 | * See also write_buffer about blocking (read_buffer has identical behaviour). | |
92658f56 PR |
32 | */ |
33 | int read_buffer(int fd, char **buffer) { | |
34 | int bytes = 0; | |
35 | int buffersize = 32; | |
6d404585 | 36 | char *new; |
92658f56 PR |
37 | *buffer = malloc(buffersize + 1); |
38 | ||
39 | while (1) { | |
40 | int result = read(fd, (*buffer) + bytes, buffersize - bytes); | |
41 | if (result > 0) | |
42 | bytes += result; | |
98b4241b PR |
43 | if (result == 0) { |
44 | errno = ECONNRESET; | |
92658f56 | 45 | goto fail; /* we should never encounter EOF here */ |
98b4241b | 46 | } |
92658f56 PR |
47 | if (result < 0 && errno != EAGAIN && errno != EWOULDBLOCK) |
48 | goto fail; | |
49 | ||
98b4241b | 50 | if (!strncmp((*buffer) + bytes - 4, "\n##\n", 4)) { |
3556560b PR |
51 | *(*buffer + bytes - 4) = 0; |
52 | break; /* success, we have the full message now */ | |
53 | } | |
54 | ||
92658f56 PR |
55 | if (bytes == buffersize) { |
56 | buffersize += 1024; | |
6d404585 | 57 | if (!(new = realloc(*buffer, buffersize + 1))) |
92658f56 | 58 | goto fail; |
6d404585 ZK |
59 | |
60 | *buffer = new; | |
92658f56 | 61 | } |
3556560b | 62 | /* TODO call select here if we encountered EAGAIN/EWOULDBLOCK */ |
92658f56 PR |
63 | } |
64 | return 1; | |
65 | fail: | |
66 | free(*buffer); | |
67 | *buffer = NULL; | |
68 | return 0; | |
69 | } | |
70 | ||
71 | /* | |
72 | * Write a buffer to a filedescriptor. Keep trying. Blocks (even on | |
73 | * SOCK_NONBLOCK) until all of the write went through. | |
74 | * | |
75 | * TODO use select on EWOULDBLOCK/EAGAIN to avoid useless spinning | |
76 | */ | |
f43c89bf | 77 | int write_buffer(int fd, const char *buffer, int length) { |
a16915cb | 78 | static const char terminate[] = "\n##\n"; |
f43c89bf | 79 | int done = 0; |
92658f56 | 80 | int written = 0; |
f43c89bf | 81 | write: |
92658f56 PR |
82 | while (1) { |
83 | int result = write(fd, buffer + written, length - written); | |
84 | if (result > 0) | |
85 | written += result; | |
86 | if (result < 0 && errno != EWOULDBLOCK && errno != EAGAIN) | |
f43c89bf PR |
87 | return 0; /* too bad */ |
88 | if (written == length) { | |
89 | if (done) | |
90 | return 1; | |
91 | else | |
92 | break; /* done */ | |
93 | } | |
92658f56 | 94 | } |
a16915cb | 95 | |
f43c89bf PR |
96 | buffer = terminate; |
97 | length = 4; | |
98 | written = 0; | |
99 | done = 1; | |
100 | goto write; | |
92658f56 | 101 | } |
4fcbeed6 | 102 | |
14e01287 | 103 | char *format_buffer(const char *what, const char *id, va_list ap) |
4fcbeed6 PR |
104 | { |
105 | char *buffer, *old; | |
106 | char *next; | |
aac236f4 | 107 | int keylen; |
4fcbeed6 | 108 | |
14e01287 | 109 | dm_asprintf(&buffer, "%s = \"%s\"\n", what, id); |
4fcbeed6 PR |
110 | if (!buffer) goto fail; |
111 | ||
6e4e3082 | 112 | while ((next = va_arg(ap, char *))) { |
4fcbeed6 | 113 | old = buffer; |
aac236f4 PR |
114 | assert(strchr(next, '=')); |
115 | keylen = strchr(next, '=') - next; | |
116 | if (strstr(next, "%d")) { | |
117 | int value = va_arg(ap, int); | |
118 | dm_asprintf(&buffer, "%s%.*s= %d\n", buffer, keylen, next, value); | |
119 | dm_free(old); | |
120 | } else if (strstr(next, "%s")) { | |
121 | char *value = va_arg(ap, char *); | |
122 | dm_asprintf(&buffer, "%s%.*s= \"%s\"\n", buffer, keylen, next, value); | |
123 | dm_free(old); | |
124 | } else if (strstr(next, "%b")) { | |
125 | char *block = va_arg(ap, char *); | |
126 | if (!block) | |
127 | continue; | |
128 | dm_asprintf(&buffer, "%s%.*s%s", buffer, keylen, next, block); | |
4fcbeed6 | 129 | dm_free(old); |
4fcbeed6 PR |
130 | } else { |
131 | dm_asprintf(&buffer, "%s%s", buffer, next); | |
132 | dm_free(old); | |
4fcbeed6 | 133 | } |
aac236f4 | 134 | if (!buffer) goto fail; |
4fcbeed6 PR |
135 | } |
136 | ||
4fcbeed6 PR |
137 | return buffer; |
138 | fail: | |
139 | dm_free(buffer); | |
140 | return NULL; | |
141 | } |