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15637ed4 RG |
1 | /* |
2 | * Copyright (c) 1983 Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * 3. All advertising materials mentioning features or use of this software | |
14 | * must display the following acknowledgement: | |
15 | * This product includes software developed by the University of | |
16 | * California, Berkeley and its contributors. | |
17 | * 4. Neither the name of the University nor the names of its contributors | |
18 | * may be used to endorse or promote products derived from this software | |
19 | * without specific prior written permission. | |
20 | * | |
21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
31 | * SUCH DAMAGE. | |
32 | */ | |
33 | ||
34 | #ifndef lint | |
35 | static char sccsid[] = "@(#)look_up.c 5.7 (Berkeley) 3/1/91"; | |
36 | #endif /* not lint */ | |
37 | ||
38 | #include <sys/types.h> | |
39 | #include <sys/socket.h> | |
40 | #include <netinet/in.h> | |
41 | #include <protocols/talkd.h> | |
42 | #include <errno.h> | |
43 | #include "talk_ctl.h" | |
44 | #include "talk.h" | |
45 | ||
46 | /* | |
47 | * See if the local daemon has an invitation for us. | |
48 | */ | |
49 | check_local() | |
50 | { | |
51 | CTL_RESPONSE response; | |
52 | register CTL_RESPONSE *rp = &response; | |
53 | ||
54 | /* the rest of msg was set up in get_names */ | |
55 | #ifdef MSG_EOR | |
56 | /* copy new style sockaddr to old, swap family (short in old) */ | |
57 | msg.ctl_addr = *(struct osockaddr *)&ctl_addr; | |
58 | msg.ctl_addr.sa_family = htons(ctl_addr.sin_family); | |
59 | #else | |
60 | msg.ctl_addr = *(struct sockaddr *)&ctl_addr; | |
61 | #endif | |
62 | /* must be initiating a talk */ | |
63 | if (!look_for_invite(rp)) | |
64 | return (0); | |
65 | /* | |
66 | * There was an invitation waiting for us, | |
67 | * so connect with the other (hopefully waiting) party | |
68 | */ | |
69 | current_state = "Waiting to connect with caller"; | |
70 | do { | |
71 | if (rp->addr.sa_family != AF_INET) | |
72 | p_error("Response uses invalid network address"); | |
73 | errno = 0; | |
74 | if (connect(sockt, | |
75 | (struct sockaddr *)&rp->addr, sizeof (rp->addr)) != -1) | |
76 | return (1); | |
77 | } while (errno == EINTR); | |
78 | if (errno == ECONNREFUSED) { | |
79 | /* | |
80 | * The caller gave up, but his invitation somehow | |
81 | * was not cleared. Clear it and initiate an | |
82 | * invitation. (We know there are no newer invitations, | |
83 | * the talkd works LIFO.) | |
84 | */ | |
85 | ctl_transact(his_machine_addr, msg, DELETE, rp); | |
86 | close(sockt); | |
87 | open_sockt(); | |
88 | return (0); | |
89 | } | |
90 | p_error("Unable to connect with initiator"); | |
91 | /*NOTREACHED*/ | |
92 | } | |
93 | ||
94 | /* | |
95 | * Look for an invitation on 'machine' | |
96 | */ | |
97 | look_for_invite(rp) | |
98 | CTL_RESPONSE *rp; | |
99 | { | |
100 | struct in_addr machine_addr; | |
101 | ||
102 | current_state = "Checking for invitation on caller's machine"; | |
103 | ctl_transact(his_machine_addr, msg, LOOK_UP, rp); | |
104 | /* the switch is for later options, such as multiple invitations */ | |
105 | switch (rp->answer) { | |
106 | ||
107 | case SUCCESS: | |
108 | msg.id_num = htonl(rp->id_num); | |
109 | return (1); | |
110 | ||
111 | default: | |
112 | /* there wasn't an invitation waiting for us */ | |
113 | return (0); | |
114 | } | |
115 | } |