1 /* tftp_prepare.c: common "first packet" thing for client routines */
2
3 /*
4 * Copyright (C) 1999 Uwe Ohse
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21 #include "config.h"
22 #include <sys/types.h>
23 #include <sys/ioctl.h>
24 #include <sys/stat.h>
25 #include <fcntl.h>
26
27 #include <sys/socket.h>
28 #include <netinet/in.h>
29 #include <netdb.h>
30 #include "no_tftp.h"
31 #ifdef HAVE_ARPA_INET_H
32 #include <arpa/inet.h>
33 #endif
34
35 #include <syslog.h>
36 #include <errno.h>
37 #include <unistd.h>
38 #include <string.h>
39 #include <signal.h>
40 #include "timselsysdep.h"
41 #include "str_ulong.h"
42 #include "str2num.h"
43 #include "tftplib.h"
44
45 /*
46 *
47 */
48 size_t
tftp_prepare_rq(int type,const char * server,unsigned short port,const char * remotefilename,struct sockaddr_in * s_in,int * may_get_oack,struct tftplib_ctrl * flags)49 tftp_prepare_rq(int type, const char *server, unsigned short port, const char *remotefilename, struct sockaddr_in *s_in,
50 int *may_get_oack, struct tftplib_ctrl *flags)
51 {
52 struct hostent *hp;
53 size_t l;
54 size_t sendlength;
55 struct in_addr ina;
56
57 if (0==inet_aton(server,&ina)) {
58 hp = gethostbyname (server);
59 if (hp == NULL) { int e=errno;syslog(LOG_ERR,"can't resolve hostname");errno=e; return 0; }
60 memcpy (&s_in->sin_addr, hp->h_addr, hp->h_length);
61 } else {
62 memcpy (&s_in->sin_addr, &ina, sizeof(ina));
63 }
64 s_in->sin_port = port;
65
66 /* so far, so good ... now do that protocol startup */
67
68 /*
69 * 2 bytes string 1 byte string 1 byte
70 * ------------------------------------------------
71 * | Opcode | Filename | 0 | Mode | 0 |
72 * ------------------------------------------------
73 */
74 flags->sendbuf.hdr->th_opcode=htons(type);
75 sendlength=2;
76
77 l=strlen(remotefilename)+1; /* include \0 */
78 if (sendlength+l>512) goto toolong;
79 memcpy(flags->sendbuf.buf+2,remotefilename,l);
80 sendlength+=l;
81 if (flags->netascii) {
82 if (sendlength+9>512) goto toolong;
83 memcpy(flags->sendbuf.buf+sendlength,"netascii",9); /* \0 */
84 sendlength+=9;
85 } else {
86 if (sendlength+6>512) goto toolong;
87 memcpy(flags->sendbuf.buf+sendlength,"octet",6); /* \0 */
88 sendlength+=6;
89 }
90 if (flags->segsize!=512) {
91 char buf[STR_ULONG];
92 if (sendlength+8>512) goto toolong;
93 memcpy(flags->sendbuf.buf+sendlength,"blksize",8); /* \0 */
94 sendlength+=8;
95
96 l=str_ulong(buf,flags->segsize)+1; /* \0 */
97 if (sendlength+l>512) goto toolong;
98 memcpy(flags->sendbuf.buf+sendlength,buf,l);
99 sendlength+=l;
100 *may_get_oack=1;
101 }
102 if (flags->timeout!=5) {
103 char buf[STR_ULONG];
104 if (sendlength+8>512) goto toolong;
105 memcpy(flags->sendbuf.buf+sendlength,"timeout",8); /* \0 */
106 sendlength+=8;
107 l=str_ulong(buf,flags->timeout)+1;
108 if (sendlength+l>512) goto toolong;
109 memcpy(flags->sendbuf.buf+sendlength,buf,l);
110 sendlength+=l;
111 *may_get_oack=1;
112 }
113 if (flags->revision) {
114 if (sendlength+9>512) goto toolong;
115 memcpy(flags->sendbuf.buf+sendlength,"revision",9); /* \0 */
116 sendlength+=9;
117 l=strlen(flags->revision)+1;
118 if (sendlength+l>512) goto toolong;
119 memcpy(flags->sendbuf.buf+sendlength,flags->revision,l);
120 sendlength+=l;
121 *may_get_oack=1;
122 }
123 if (flags->send_garbage) {
124 if (sendlength+2>512) goto toolong;
125 memcpy(flags->sendbuf.buf+sendlength,"AZ",2);
126 sendlength+=2;
127 }
128 return sendlength;
129 toolong:
130 { int e=errno;syslog(LOG_ERR,"?RQ packet would be too long");errno=e; return 0; }
131 return 0;
132 }
133