xref: /linux/arch/um/drivers/mconsole_user.c (revision d8327c784b51b57dac2c26cfad87dce0d68dfd98)
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         { "stack", mconsole_stack, MCONSOLE_INTR },
34 };
35 
36 /* Initialized in mconsole_init, which is an initcall */
37 char mconsole_socket_name[256];
38 
39 int mconsole_reply_v0(struct mc_request *req, char *reply)
40 {
41         struct iovec iov;
42         struct msghdr msg;
43 
44         iov.iov_base = reply;
45         iov.iov_len = strlen(reply);
46 
47         msg.msg_name = &(req->origin);
48         msg.msg_namelen = req->originlen;
49         msg.msg_iov = &iov;
50         msg.msg_iovlen = 1;
51         msg.msg_control = NULL;
52         msg.msg_controllen = 0;
53         msg.msg_flags = 0;
54 
55         return sendmsg(req->originating_fd, &msg, 0);
56 }
57 
58 static struct mconsole_command *mconsole_parse(struct mc_request *req)
59 {
60 	struct mconsole_command *cmd;
61 	int i;
62 
63 	for(i=0;i<sizeof(commands)/sizeof(commands[0]);i++){
64 		cmd = &commands[i];
65 		if(!strncmp(req->request.data, cmd->command,
66 			    strlen(cmd->command))){
67 			return(cmd);
68 		}
69 	}
70 	return(NULL);
71 }
72 
73 #define MIN(a,b) ((a)<(b) ? (a):(b))
74 
75 #define STRINGX(x) #x
76 #define STRING(x) STRINGX(x)
77 
78 int mconsole_get_request(int fd, struct mc_request *req)
79 {
80 	int len;
81 
82 	req->originlen = sizeof(req->origin);
83 	req->len = recvfrom(fd, &req->request, sizeof(req->request), 0,
84 			    (struct sockaddr *) req->origin, &req->originlen);
85 	if (req->len < 0)
86 		return 0;
87 
88 	req->originating_fd = fd;
89 
90 	if(req->request.magic != MCONSOLE_MAGIC){
91 		/* Unversioned request */
92 		len = MIN(sizeof(req->request.data) - 1,
93 			  strlen((char *) &req->request));
94 		memmove(req->request.data, &req->request, len);
95 		req->request.data[len] = '\0';
96 
97 		req->request.magic = MCONSOLE_MAGIC;
98 		req->request.version = 0;
99 		req->request.len = len;
100 
101 		mconsole_reply_v0(req, "ERR Version 0 mconsole clients are "
102 				  "not supported by this driver");
103 		return(0);
104 	}
105 
106 	if(req->request.len >= MCONSOLE_MAX_DATA){
107 		mconsole_reply(req, "Request too large", 1, 0);
108 		return(0);
109 	}
110 	if(req->request.version != MCONSOLE_VERSION){
111 		mconsole_reply(req, "This driver only supports version "
112                                STRING(MCONSOLE_VERSION) " clients", 1, 0);
113 	}
114 
115 	req->request.data[req->request.len] = '\0';
116 	req->cmd = mconsole_parse(req);
117 	if(req->cmd == NULL){
118 		mconsole_reply(req, "Unknown command", 1, 0);
119 		return(0);
120 	}
121 
122 	return(1);
123 }
124 
125 int mconsole_reply_len(struct mc_request *req, const char *str, int total,
126 		       int err, int more)
127 {
128 	struct mconsole_reply reply;
129 	int len, n;
130 
131 	do {
132 		reply.err = err;
133 
134 		/* err can only be true on the first packet */
135 		err = 0;
136 
137 		len = MIN(total, MCONSOLE_MAX_DATA - 1);
138 
139 		if(len == total) reply.more = more;
140 		else reply.more = 1;
141 
142 		memcpy(reply.data, str, len);
143 		reply.data[len] = '\0';
144 		total -= len;
145 		str += len;
146 		reply.len = len + 1;
147 
148 		len = sizeof(reply) + reply.len - sizeof(reply.data);
149 
150 		n = sendto(req->originating_fd, &reply, len, 0,
151 			   (struct sockaddr *) req->origin, req->originlen);
152 
153 		if(n < 0) return(-errno);
154 	} while(total > 0);
155 	return(0);
156 }
157 
158 int mconsole_reply(struct mc_request *req, const char *str, int err, int more)
159 {
160 	return mconsole_reply_len(req, str, strlen(str), err, more);
161 }
162 
163 
164 int mconsole_unlink_socket(void)
165 {
166 	unlink(mconsole_socket_name);
167 	return 0;
168 }
169 
170 static int notify_sock = -1;
171 
172 int mconsole_notify(char *sock_name, int type, const void *data, int len)
173 {
174 	struct sockaddr_un target;
175 	struct mconsole_notify packet;
176 	int n, err = 0;
177 
178 	lock_notify();
179 	if(notify_sock < 0){
180 		notify_sock = socket(PF_UNIX, SOCK_DGRAM, 0);
181 		if(notify_sock < 0){
182 			err = -errno;
183 			printk("mconsole_notify - socket failed, errno = %d\n",
184 			       err);
185 		}
186 	}
187 	unlock_notify();
188 
189 	if(err)
190 		return(err);
191 
192 	target.sun_family = AF_UNIX;
193 	strcpy(target.sun_path, sock_name);
194 
195 	packet.magic = MCONSOLE_MAGIC;
196 	packet.version = MCONSOLE_VERSION;
197 	packet.type = type;
198 	len = (len > sizeof(packet.data)) ? sizeof(packet.data) : len;
199 	packet.len = len;
200 	memcpy(packet.data, data, len);
201 
202 	err = 0;
203 	len = sizeof(packet) + packet.len - sizeof(packet.data);
204 	n = sendto(notify_sock, &packet, len, 0, (struct sockaddr *) &target,
205 		   sizeof(target));
206 	if(n < 0){
207 		err = -errno;
208 		printk("mconsole_notify - sendto failed, errno = %d\n", errno);
209 	}
210 	return(err);
211 }
212 
213 /*
214  * Overrides for Emacs so that we follow Linus's tabbing style.
215  * Emacs will notice this stuff at the end of the file and automatically
216  * adjust the settings for this buffer only.  This must remain at the end
217  * of the file.
218  * ---------------------------------------------------------------------------
219  * Local variables:
220  * c-file-style: "linux"
221  * End:
222  */
223