xref: /netbsd-src/share/examples/pud/intro/intro.c (revision efe797dc32182d1b9047d829623cdf336ee1f6f3)
1 /*	$NetBSD: intro.c,v 1.4 2007/11/28 16:59:02 pooka Exp $	*/
2 
3 /*
4  * El extra-simplo example of the userspace driver framework.
5  *
6  * Eventually there will be a library a la libpuffs (perhaps,
7  * gasp, even the same lib), but for now it's all manual until
8  * I get it figured out.
9  *
10  * So how to run this?
11  * 0) sh MAKEDEV putter (if you don't have a freshly created /dev)
12  * 1) run this program with the argument "/dev/pud"
13  * 2) mknod a char device with the major 377 (see sources below)
14  * 3) echo ascii art and jokes into device created in previous step
15  *    or read the device
16  */
17 
18 #include <sys/types.h>
19 
20 #include <dev/pud/pud_msgif.h>
21 
22 #include <err.h>
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <unistd.h>
29 
30 #include "common.h"
31 
32 #define DEFALLOC 1024*1024
33 #define ECHOSTR1 "Would you like some sauce diable with that?\n"
34 #define ECHOSTR2 "Nej tack, you fool, I'm happy with my tournedos Rossini\n"
35 #define NSTR 2
36 
37 const char *curstr = ECHOSTR1;
38 
39 #ifndef MIN
40 #define MIN(a,b) ((a)<(b)?(a):(b))
41 #endif
42 
43 int
main(int argc,char * argv[])44 main(int argc, char *argv[])
45 {
46 	struct pud_req *pdr = malloc(DEFALLOC);
47 	struct pud_conf_reg pcr;
48 	int fd;
49 	ssize_t n;
50 
51 	if (argc != 2)
52 		errx(1, "args");
53 
54 	/*
55 	 * open pud device
56 	 */
57 	fd = open(argv[1], O_RDWR);
58 	if (fd == -1)
59 		err(1, "open");
60 
61 	/*
62 	 * register our major number
63 	 */
64 	memset(&pcr, 0, sizeof(pcr));
65 	pcr.pm_pdr.pdr_pth.pth_framelen = sizeof(struct pud_conf_reg);
66 	pcr.pm_version = PUD_DEVELVERSION | PUD_VERSION;
67 	pcr.pm_pdr.pdr_reqclass = PUD_REQ_CONF;
68 	pcr.pm_pdr.pdr_reqtype = PUD_CONF_REG;
69 
70 	pcr.pm_regdev = makedev(377, 0);
71 	pcr.pm_flags = PUD_CONFFLAG_BDEV;
72 	strlcpy(pcr.pm_devname, "testdev", sizeof(pcr.pm_devname));
73 
74 	n = write(fd, &pcr, pcr.pm_pdr.pdr_pth.pth_framelen);
75 	if (n == -1)
76 		err(1, "configure write");
77 
78 	/*
79 	 * process requests
80 	 */
81 	for (;;) {
82 		n = read(fd, pdr, DEFALLOC);
83 		printf("read %d %d\n", n, errno);
84 
85 		switch (pdr->pdr_reqtype) {
86 		case PUD_CDEV_OPEN:
87 		case PUD_CDEV_CLOSE:
88 			printf("got openclose %d\n", pdr->pdr_reqtype);
89 			pdr->pdr_rv = 0;
90 			break;
91 
92 		case PUD_CDEV_READ:
93 		/* uh oh case PUD_BDEV_STRATREAD: */
94 		{
95 			struct pud_creq_read *pc_read;
96 			size_t clen;
97 
98 			pc_read = (void *)pdr;
99 			printf("read from offset %llu, resid %zu\n",
100 			    (unsigned long long)pc_read->pm_offset,
101 			    pc_read->pm_resid);
102 
103 			clen = MIN(strlen(curstr), pc_read->pm_resid);
104 			strncpy(pc_read->pm_data, curstr, clen);
105 			if (pdr->pdr_reqclass == PUD_REQ_BDEV) {
106 				clen = pc_read->pm_resid;
107 				pc_read->pm_resid = 0;
108 			} else {
109 				pc_read->pm_resid -= clen;
110 			}
111 			pdr->pdr_pth.pth_framelen =
112 			    sizeof(struct pud_creq_read) + clen;
113 		}
114 			break;
115 
116 		case PUD_CDEV_WRITE:
117 		/* uh uh oh case PUD_BDEV_STRATWRITE: */
118 		{
119 			struct pud_creq_write *pc_write;
120 
121 			pc_write = (void *)pdr;
122 			printf("write to offset %llu, resid %zu\n",
123 			    (unsigned long long)pc_write->pm_offset,
124 			    pc_write->pm_resid);
125 
126 			pc_write->pm_data[pc_write->pm_resid] = '\0';
127 			printf("got via write: %s", pc_write->pm_data);
128 			pdr->pdr_pth.pth_framelen =
129 			    sizeof(struct pud_creq_write);
130 			pc_write->pm_resid = 0;
131 		}
132 			break;
133 
134 		case PUD_CDEV_IOCTL:
135 		{
136 			struct pud_req_ioctl *pc_ioctl;
137 			int *iocval;
138 
139 			pc_ioctl = (void *)pdr;
140 			switch (pc_ioctl->pm_iocmd) {
141 			case INTROTOGGLE:
142 			case INTROTOGGLE_R:
143 				iocval = (int *)pc_ioctl->pm_data;
144 				if (*iocval < 0 || *iocval > 2) {
145 					pdr->pdr_rv = ERANGE;
146 					break;
147 				}
148 
149 				if (*iocval == 1)
150 					curstr = ECHOSTR1;
151 				else
152 					curstr = ECHOSTR2;
153 
154 				*iocval = 0;
155 				break;
156 			default:
157 				abort();
158 			}
159 		}
160 			break;
161 
162 		default:
163 			abort();
164 		}
165 
166 		n = write(fd, pdr, pdr->pdr_pth.pth_framelen);
167 		printf("wrote %d %d\n", n, errno);
168 	}
169 }
170