1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
28 /* All Rights Reserved */
29
30 /* LINTLIBRARY */
31
32 # include <unistd.h>
33 # include <fcntl.h>
34 # include <errno.h>
35 # include <sys/utsname.h>
36 # include <stdlib.h>
37 # include <sys/types.h>
38 # include <sys/stat.h>
39
40 #include "lp.h"
41 #include "msgs.h"
42
43 #define TURN_OFF(X,F) (void)Fcntl(X, F_SETFL, (Fcntl(X, F_GETFL, 0) & ~(F)))
44
45 #if defined(__STDC__)
46 static int checklock ( void );
47 #else
48 static int checklock();
49 #endif
50
51 /*
52 ** mconnect() - OPEN A MESSAGE PATH
53 */
54
55 #if defined(__STDC__)
mconnect(char * path,int id1,int id2)56 MESG * mconnect ( char * path, int id1, int id2 )
57 #else
58 MESG * mconnect ()
59 char *path;
60 int id1;
61 int id2;
62 #endif
63 {
64 int fd;
65 int wronly = 0;
66 int count = 0;
67 MESG *md;
68 struct stat stbuf;
69
70 /*
71 ** invoked as mconnect(path, 0, 0)
72 **
73 ** Open <path>, if isastream() is true for the returned file
74 ** descriptor, then we're done.
75 */
76
77 if (path)
78 {
79 /*
80 ** Verify that the spooler is running and that the
81 ** <path> identifies a pipe.
82 ** This prevents us from getting hung in the open
83 ** and from thinking the <path> is a non-streams pipe.
84 */
85 if (checklock() == -1)
86 return(NULL);
87 Again: if (stat(path, &stbuf) == -1)
88 return(NULL);
89 if ((stbuf.st_mode & S_IFMT) != S_IFIFO) {
90 if (count++ > 20)
91 return (NULL);
92 sleep(1);
93 goto Again;
94 }
95
96 if ((fd = Open(path, O_RDWR, 0)) == -1)
97 if ((fd = Open(path, O_WRONLY, 0)) == -1)
98 return(NULL);
99 else
100 wronly = 1;
101
102 if (isastream(fd) && !wronly)
103 {
104 #if defined(NOCONNLD)
105 int fds[2];
106
107 if (pipe(fds) != 0)
108 return(NULL);
109
110 if (ioctl(fd, I_SENDFD, fds[1]) != 0)
111 return(NULL);
112
113 (void)_Close(fd);
114
115 fd = fds[0];
116 (void)_Close(fds[1]);
117 #endif
118
119 if ((md = (MESG *)Malloc(MDSIZE)) == NULL)
120 {
121 errno = ENOMEM;
122 return(NULL);
123 }
124
125 memset(md, 0, sizeof (MESG));
126 md->gid = getgid();
127 md->on_discon = NULL;
128 md->readfd = fd;
129 md->state = MDS_IDLE;
130 md->type = MD_STREAM;
131 md->uid = getuid();
132 md->writefd = fd;
133
134 ResetFifoBuffer (md->readfd);
135 return(md);
136 }
137
138 return(NULL);
139 }
140
141 if (id1 > 0 && id2 > 0)
142 {
143 if ((md = (MESG *)Malloc(MDSIZE)) == NULL)
144 {
145 errno = ENOMEM;
146 return(NULL);
147 }
148
149 memset(md, 0, sizeof (MESG));
150 md->gid = getgid();
151 md->on_discon = NULL;
152 md->readfd = id1;
153 md->state = MDS_IDLE;
154 md->type = MD_BOUND;
155 md->uid = getuid();
156 md->writefd = id2;
157
158 ResetFifoBuffer (md->readfd);
159
160 return(md);
161 }
162
163 errno = EINVAL;
164 return(NULL);
165 }
166
167 #if defined(__STDC__)
checklock(void)168 static int checklock ( void )
169 #else
170 static int checklock()
171 #endif
172 {
173 int fd;
174 struct flock lock;
175
176 if ((fd = Open(Lp_Schedlock, O_RDONLY, 0666)) == -1)
177 return (-1);
178
179 /*
180 * Now, we try to read-lock the lock file. This can only succeed if
181 * the Spooler (lpsched) is down.
182 */
183
184 lock.l_type = F_RDLCK;
185 lock.l_whence = 0;
186 lock.l_start = 0;
187 lock.l_len = 0; /* till end of file */
188
189 if (Fcntl(fd, F_SETLK, &lock) != -1 || errno != EAGAIN)
190 {
191 (void)Close (fd);
192 return (-1);
193 }
194
195 /*
196 * We can get here only when fcntl() == -1 && errno == EAGAIN,
197 * i.e., spooler (lpsched) is running.
198 */
199
200 (void)Close (fd);
201
202 return(0);
203 }
204