1 /*
2 * SysDB - src/utils/proto.c
3 * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 #include "utils/error.h"
29 #include "utils/proto.h"
31 #include <arpa/inet.h>
32 #include <errno.h>
34 #include <limits.h>
36 #include <string.h>
37 #include <unistd.h>
39 #include <sys/select.h>
41 /*
42 * public API
43 */
45 int
46 sdb_proto_select(int fd, int type)
47 {
48 fd_set fds;
49 fd_set *readfds = NULL;
50 fd_set *writefds = NULL;
51 fd_set *exceptfds = NULL;
53 if (fd < 0) {
54 errno = EBADF;
55 return -1;
56 }
58 FD_ZERO(&fds);
60 switch (type) {
61 case SDB_PROTO_SELECTIN:
62 readfds = &fds;
63 break;
64 case SDB_PROTO_SELECTOUT:
65 writefds = &fds;
66 break;
67 case SDB_PROTO_SELECTERR:
68 exceptfds = &fds;
69 break;
70 default:
71 errno = EINVAL;
72 return -1;
73 }
75 FD_SET(fd, &fds);
77 while (42) {
78 int n;
79 errno = 0;
80 n = select(fd + 1, readfds, writefds, exceptfds, NULL);
82 if ((n < 0) && (errno != EINTR))
83 return n;
84 if (n > 0)
85 break;
86 }
87 return 0;
88 } /* sdb_proto_select */
90 ssize_t
91 sdb_proto_send(int fd, size_t msg_len, const char *msg)
92 {
93 const char *buf;
94 size_t len;
96 if ((fd < 0) || (msg_len && (! msg)))
97 return -1;
98 if (! msg_len)
99 return 0;
101 buf = msg;
102 len = msg_len;
103 while (len > 0) {
104 ssize_t status;
106 if (sdb_proto_select(fd, SDB_PROTO_SELECTOUT))
107 return -1;
109 errno = 0;
110 status = write(fd, buf, len);
111 if (status < 0) {
112 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
113 continue;
114 if (errno == EINTR)
115 continue;
117 return status;
118 }
120 len -= (size_t)status;
121 buf += status;
122 }
124 return (ssize_t)msg_len;
125 } /* sdb_proto_send */
127 ssize_t
128 sdb_proto_send_msg(int fd, uint32_t code,
129 uint32_t msg_len, const char *msg)
130 {
131 size_t len = 2 * sizeof(uint32_t) + msg_len;
132 char buffer[len];
134 uint32_t tmp;
136 tmp = htonl(code);
137 memcpy(buffer, &tmp, sizeof(tmp));
138 tmp = htonl(msg_len);
139 memcpy(buffer + sizeof(tmp), &tmp, sizeof(tmp));
141 if (msg_len)
142 memcpy(buffer + 2 * sizeof(tmp), msg, msg_len);
144 return sdb_proto_send(fd, len, buffer);
145 } /* sdb_proto_send_msg */
147 uint32_t
148 sdb_proto_get_int(sdb_strbuf_t *buf, size_t offset)
149 {
150 const char *data;
151 uint32_t n;
153 if (! buf)
154 return UINT32_MAX;
156 /* not enough data to read */
157 if (offset + sizeof(uint32_t) > sdb_strbuf_len(buf))
158 return UINT32_MAX;
160 data = sdb_strbuf_string(buf);
161 data += offset;
162 memcpy(&n, data, sizeof(n));
163 return ntohl(n);
164 } /* sdb_proto_get_int */
166 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */