xref: /illumos-gate/usr/src/cmd/ttymon/tmpeek.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 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 #include <stdio.h>
31 #include <unistd.h>
32 #include <stdlib.h>
33 #include <ctype.h>
34 #include <sys/types.h>
35 #include <sys/stropts.h>
36 #include <poll.h>
37 #include <signal.h>
38 #include <errno.h>
39 #include "ttymon.h"
40 #include "tmstruct.h"
41 #include "tmextern.h"
42 
43 #define	BRK	1
44 #define	DEL	2
45 
46 struct	strbuf *do_peek(int, int);
47 static	int	process(int, struct strbuf *);
48 
49 static	int	interrupt;
50 
51 /*
52  *	poll_data	- it polls the device, waiting for data
53  *			- return BADSPEED it <brk> is received
54  *			- return the result of process if data is received
55  *			- write a newline if <del> is received
56  *			- exit if hangup is received
57  */
58 int
59 poll_data(void)
60 {
61 	int j;
62 	struct strbuf *ptr;
63 	struct pollfd fds[1];
64 	struct sigaction sigact;
65 
66 #ifdef	DEBUG
67 	debug("in poll_data");
68 #endif
69 	if (peek_ptr != NULL) {
70 		for (j = 0; j < peek_ptr->len; j++)
71 			peek_ptr->buf[j] &= 0x7F;
72 		return (process(0, peek_ptr));
73 	}
74 	fds[0].fd = 0;
75 	fds[0].events = POLLIN;
76 	sigact.sa_flags = 0;
77 	sigact.sa_handler = sigint;
78 	(void) sigemptyset(&sigact.sa_mask);
79 	(void) sigaddset(&sigact.sa_mask, SIGINT);
80 	(void) sigaction(SIGINT, &sigact, NULL);
81 	for (;;) {
82 		interrupt = 0;
83 		if ((j = poll(fds, 1, -1)) == -1) {
84 			if (interrupt == BRK) {
85 				return (BADSPEED);
86 			}
87 			if (interrupt == DEL) { /* XXX revisit kmd */
88 				return (BADSPEED);
89 			}
90 		} else if (j > 0) {
91 			if (fds[0].revents & POLLHUP) {
92 				log("POLLHUP received, about to exit");
93 				exit(1);
94 			}
95 			if (fds[0].revents & POLLIN) {
96 				ptr = do_peek(fds[0].fd, 255);
97 				if (ptr != NULL) {
98 					return (process(fds[0].fd, ptr));
99 				}
100 			}
101 		}
102 	}
103 }
104 
105 /*
106  *	process	- process the data
107  *		- return GOODNAME if it is a non-empty line
108  *		- return NONAME if a <CR> is received
109  *		- return BADNAME if zero byte is detected
110  *		- except the case of GOODNAME, data will be pulled out
111  *		  of the stream
112  */
113 static int
114 process(
115 	int	fd,		/* fd to read data from if necessary	*/
116 	struct strbuf *ptr)	/* ptr that holds data in ptr->buf	*/
117 {
118 	unsigned i;
119 	char	junk[BUFSIZ];
120 
121 	for (i = 0; i < ptr->len; i++) {
122 		if (ptr->buf[i] == '\0') {
123 			(void) read(fd, junk, i+1);
124 			return (BADSPEED);
125 		} else if ((ptr->buf[i] == '\n') || (ptr->buf[i] == '\r')) {
126 			if (i == 0) {
127 				(void) read(fd, junk, ptr->len);
128 				return (NONAME);
129 			} else
130 				return (GOODNAME);
131 		}
132 	}	/* end for loop */
133 	/* end of input is encountered */
134 #ifdef	DEBUG
135 	debug("in process: EOF encountered");
136 #endif
137 	exit(1);
138 	/*NOTREACHED*/
139 }
140 
141 /*
142  *	do_peek	- peek at the stream to get the data
143  *	int	fd;	fd to do the ioctl on
144  *	int	n;	maxlen of data to peek at
145  *		- this only called when POLLIN is detected,
146  *		- so there should always be something there
147  *		- return a ptr to the buf that contains the data
148  *		- return NULL if nothing to peek at
149  */
150 struct	strbuf	*
151 do_peek(int fd, int n)
152 {
153 	int	 ret;
154 	static	 struct strpeek peek;
155 	struct strpeek *peekp;
156 	static	 char	buf[BUFSIZ];
157 
158 #ifdef	DEBUG
159 	debug("in do_peek");
160 #endif
161 
162 	peekp = &peek;
163 	peekp->flags = 0;
164 	/* need to ask for ctl info to avoid bug in I_PEEK code */
165 	peekp->ctlbuf.maxlen = 1;
166 	peekp->ctlbuf.buf = buf;
167 	peekp->databuf.maxlen = n;
168 	peekp->databuf.buf = buf;
169 	ret = ioctl(fd, I_PEEK, &peek);
170 	if (ret == -1) {
171 		log("do_peek: I_PEEK failed: %s", errno);
172 		exit(1);
173 	}
174 	if (ret == 0) {
175 		return (NULL);
176 	}
177 	return (&(peekp->databuf));
178 }
179 
180 /*
181  *	sigint	- this is called when SIGINT is caught
182  */
183 void
184 sigint(int s __unused)
185 {
186 	struct strbuf *ptr;
187 	char   junk[2];
188 
189 #ifdef	DEBUG
190 	debug("in sigint");
191 #endif
192 	ptr = do_peek(0, 1);
193 	if (ptr == NULL) {	/* somebody type <del> */
194 		interrupt = DEL;
195 	} else {
196 		if (ptr->buf[0] == '\0') {
197 			/* somebody type <brk> or frame error */
198 			(void) read(0, junk, 1);
199 			interrupt = BRK;
200 		}
201 	}
202 }
203