xref: /openbmc/linux/arch/um/drivers/mconsole_user.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
3  * Copyright (C) 2001 - 2003 Jeff Dike (jdike@addtoit.com)
4  * Licensed under the GPL
5  */
6 
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <errno.h>
10 #include <signal.h>
11 #include <sys/socket.h>
12 #include <sys/types.h>
13 #include <sys/uio.h>
14 #include <sys/un.h>
15 #include <unistd.h>
16 #include "user.h"
17 #include "mconsole.h"
18 #include "umid.h"
19 
20 static struct mconsole_command commands[] = {
21 	{ "version", mconsole_version, MCONSOLE_INTR },
22 	{ "halt", mconsole_halt, MCONSOLE_PROC },
23 	{ "reboot", mconsole_reboot, MCONSOLE_PROC },
24 	{ "config", mconsole_config, MCONSOLE_PROC },
25 	{ "remove", mconsole_remove, MCONSOLE_PROC },
26 	{ "sysrq", mconsole_sysrq, MCONSOLE_INTR },
27 	{ "help", mconsole_help, MCONSOLE_INTR },
28 	{ "cad", mconsole_cad, MCONSOLE_INTR },
29 	{ "stop", mconsole_stop, MCONSOLE_PROC },
30 	{ "go", mconsole_go, MCONSOLE_INTR },
31 	{ "log", mconsole_log, MCONSOLE_INTR },
32 	{ "proc", mconsole_proc, MCONSOLE_PROC },
33 };
34 
35 /* Initialized in mconsole_init, which is an initcall */
36 char mconsole_socket_name[256];
37 
38 int mconsole_reply_v0(struct mc_request *req, char *reply)
39 {
40         struct iovec iov;
41         struct msghdr msg;
42 
43         iov.iov_base = reply;
44         iov.iov_len = strlen(reply);
45 
46         msg.msg_name = &(req->origin);
47         msg.msg_namelen = req->originlen;
48         msg.msg_iov = &iov;
49         msg.msg_iovlen = 1;
50         msg.msg_control = NULL;
51         msg.msg_controllen = 0;
52         msg.msg_flags = 0;
53 
54         return sendmsg(req->originating_fd, &msg, 0);
55 }
56 
57 static struct mconsole_command *mconsole_parse(struct mc_request *req)
58 {
59 	struct mconsole_command *cmd;
60 	int i;
61 
62 	for(i=0;i<sizeof(commands)/sizeof(commands[0]);i++){
63 		cmd = &commands[i];
64 		if(!strncmp(req->request.data, cmd->command,
65 			    strlen(cmd->command))){
66 			return(cmd);
67 		}
68 	}
69 	return(NULL);
70 }
71 
72 #define MIN(a,b) ((a)<(b) ? (a):(b))
73 
74 #define STRINGX(x) #x
75 #define STRING(x) STRINGX(x)
76 
77 int mconsole_get_request(int fd, struct mc_request *req)
78 {
79 	int len;
80 
81 	req->originlen = sizeof(req->origin);
82 	req->len = recvfrom(fd, &req->request, sizeof(req->request), 0,
83 			    (struct sockaddr *) req->origin, &req->originlen);
84 	if (req->len < 0)
85 		return 0;
86 
87 	req->originating_fd = fd;
88 
89 	if(req->request.magic != MCONSOLE_MAGIC){
90 		/* Unversioned request */
91 		len = MIN(sizeof(req->request.data) - 1,
92 			  strlen((char *) &req->request));
93 		memmove(req->request.data, &req->request, len);
94 		req->request.data[len] = '\0';
95 
96 		req->request.magic = MCONSOLE_MAGIC;
97 		req->request.version = 0;
98 		req->request.len = len;
99 
100 		mconsole_reply_v0(req, "ERR Version 0 mconsole clients are "
101 				  "not supported by this driver");
102 		return(0);
103 	}
104 
105 	if(req->request.len >= MCONSOLE_MAX_DATA){
106 		mconsole_reply(req, "Request too large", 1, 0);
107 		return(0);
108 	}
109 	if(req->request.version != MCONSOLE_VERSION){
110 		mconsole_reply(req, "This driver only supports version "
111                                STRING(MCONSOLE_VERSION) " clients", 1, 0);
112 	}
113 
114 	req->request.data[req->request.len] = '\0';
115 	req->cmd = mconsole_parse(req);
116 	if(req->cmd == NULL){
117 		mconsole_reply(req, "Unknown command", 1, 0);
118 		return(0);
119 	}
120 
121 	return(1);
122 }
123 
124 int mconsole_reply(struct mc_request *req, char *str, int err, int more)
125 {
126 	struct mconsole_reply reply;
127 	int total, len, n;
128 
129 	total = strlen(str);
130 	do {
131 		reply.err = err;
132 
133 		/* err can only be true on the first packet */
134 		err = 0;
135 
136 		len = MIN(total, MCONSOLE_MAX_DATA - 1);
137 
138 		if(len == total) reply.more = more;
139 		else reply.more = 1;
140 
141 		memcpy(reply.data, str, len);
142 		reply.data[len] = '\0';
143 		total -= len;
144 		str += len;
145 		reply.len = len + 1;
146 
147 		len = sizeof(reply) + reply.len - sizeof(reply.data);
148 
149 		n = sendto(req->originating_fd, &reply, len, 0,
150 			   (struct sockaddr *) req->origin, req->originlen);
151 
152 		if(n < 0) return(-errno);
153 	} while(total > 0);
154 	return(0);
155 }
156 
157 int mconsole_unlink_socket(void)
158 {
159 	unlink(mconsole_socket_name);
160 	return 0;
161 }
162 
163 static int notify_sock = -1;
164 
165 int mconsole_notify(char *sock_name, int type, const void *data, int len)
166 {
167 	struct sockaddr_un target;
168 	struct mconsole_notify packet;
169 	int n, err = 0;
170 
171 	lock_notify();
172 	if(notify_sock < 0){
173 		notify_sock = socket(PF_UNIX, SOCK_DGRAM, 0);
174 		if(notify_sock < 0){
175 			printk("mconsole_notify - socket failed, errno = %d\n",
176 			       errno);
177 			err = -errno;
178 		}
179 	}
180 	unlock_notify();
181 
182 	if(err)
183 		return(err);
184 
185 	target.sun_family = AF_UNIX;
186 	strcpy(target.sun_path, sock_name);
187 
188 	packet.magic = MCONSOLE_MAGIC;
189 	packet.version = MCONSOLE_VERSION;
190 	packet.type = type;
191 	len = (len > sizeof(packet.data)) ? sizeof(packet.data) : len;
192 	packet.len = len;
193 	memcpy(packet.data, data, len);
194 
195 	err = 0;
196 	len = sizeof(packet) + packet.len - sizeof(packet.data);
197 	n = sendto(notify_sock, &packet, len, 0, (struct sockaddr *) &target,
198 		   sizeof(target));
199 	if(n < 0){
200 		printk("mconsole_notify - sendto failed, errno = %d\n", errno);
201 		err = -errno;
202 	}
203 	return(err);
204 }
205 
206 /*
207  * Overrides for Emacs so that we follow Linus's tabbing style.
208  * Emacs will notice this stuff at the end of the file and automatically
209  * adjust the settings for this buffer only.  This must remain at the end
210  * of the file.
211  * ---------------------------------------------------------------------------
212  * Local variables:
213  * c-file-style: "linux"
214  * End:
215  */
216