masqmail

view src/connect.c @ 56:f6a6f55b7b9e

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added old manual from the old website it is dated May/July 2000
author meillo@marmaro.de
date Sat, 29 May 2010 21:51:13 +0200
parents 08114f7dcc23
children a80ebfa16cd5
line source
1 /* MasqMail
2 Copyright (C) 1999 Oliver Kurth
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18 #include "masqmail.h"
19
20 static GList*
21 resolve_ip(GList * list, gchar * ip)
22 {
23 struct in_addr ia;
24 if (inet_aton(ip, &ia)) {
25 mxip_addr mxip;
26
27 mxip.name = g_strdup(ip);
28 mxip.pref = 0;
29 mxip.ip = (guint32) * (guint32 *) (&ia);
30 list = g_list_append(list, g_memdup(&mxip, sizeof(mxip)));
31 }
32 /* logwrite(LOG_ALERT, "invalid address '%s': inet_aton() failed\n", ip); */
33 return NULL;
34 }
35
36 mxip_addr*
37 connect_hostlist(int *psockfd, gchar * host, guint port, GList * addr_list)
38 {
39 GList *addr_node;
40 struct sockaddr_in saddr;
41
42 DEBUG(5) debugf("connect_hostlist entered\n");
43
44 for (addr_node = g_list_first(addr_list); addr_node; addr_node = g_list_next(addr_node)) {
45 mxip_addr *addr = (mxip_addr *) (addr_node->data);
46
47 *psockfd = socket(PF_INET, SOCK_STREAM, 0);
48
49 memset(&saddr, 0, sizeof(saddr));
50
51 saddr.sin_family = AF_INET;
52 saddr.sin_port = htons(port);
53
54 /* clumsy, but makes compiler happy: */
55 saddr.sin_addr = *(struct in_addr *) (&(addr->ip));
56 DEBUG(5) debugf("trying ip %s port %d\n", inet_ntoa(saddr.sin_addr), port);
57 if (connect(*psockfd, (struct sockaddr *) (&saddr), sizeof(saddr)) == 0) {
58 DEBUG(5) debugf("connected to %s\n", inet_ntoa(saddr.sin_addr));
59 return addr;
60 } else {
61 int saved_errno = errno;
62
63 close(*psockfd);
64
65 logwrite(LOG_WARNING, "connection to %s failed: %s\n", inet_ntoa(saddr.sin_addr), strerror(errno));
66
67 errno = saved_errno;
68
69 if ((saved_errno != ECONNREFUSED)
70 && (saved_errno != ETIMEDOUT)
71 && (saved_errno != ENETUNREACH)
72 && (saved_errno != EHOSTUNREACH))
73 return NULL;
74 }
75 }
76 return NULL;
77 }
78
79 /* Given a list of resolver functions, this function
80 resolve the host and tries to connect to the addresses
81 returned. If a connection attemp is timed out or refused,
82 the next address is tried.
83
84 TODO: the resolver functions might return duplicate addresses,
85 if attempt failed for one it should not be tried again.
86 */
87
88 mxip_addr*
89 connect_resolvelist(int *psockfd, gchar * host, guint port, GList * res_func_list)
90 {
91 GList *res_node;
92 GList *addr_list;
93
94 DEBUG(5) debugf("connect_resolvelist entered\n");
95
96 h_errno = 0;
97
98 if (isdigit(host[0])) {
99 mxip_addr *addr;
100
101 addr_list = resolve_ip(NULL, host);
102 if (addr_list) {
103 addr = connect_hostlist(psockfd, host, port, addr_list);
104 g_list_free(addr_list);
105 return addr;
106 }
107 /* previous versions complained, until someone tried to use a hostname
108 out there that begins with a digit. eg. '3dwars.de'. */
109 }
110
111 if (res_func_list == NULL) {
112 logwrite(LOG_ALERT, "res_funcs == NULL !!!\n");
113 exit(EXIT_FAILURE);
114 }
115
116 foreach(res_func_list, res_node) {
117 resolve_func res_func;
118 DEBUG(6) debugf("connect_resolvelist 1a\n");
119 res_func = (resolve_func) (res_node->data);
120
121 if (res_func == NULL) {
122 logwrite(LOG_ALERT, "res_func == NULL !!!\n");
123 exit(EXIT_FAILURE);
124 }
125
126 errno = 0;
127 if ((addr_list = res_func(NULL, host))) {
128
129 mxip_addr *addr;
130 if ((addr = connect_hostlist(psockfd, host, port, addr_list)))
131 return addr;
132
133 DEBUG(5) {
134 debugf("connect_hostlist failed: %s\n", strerror(errno));
135 }
136
137 g_list_free(addr_list);
138 } else {
139 if (!g_list_next(res_node)) {
140 logwrite(LOG_ALERT, "could not resolve %s: %s\n", host, hstrerror(h_errno));
141 }
142 }
143 }
144 return NULL;
145
146 }