arch/um/drivers/mconsole_user.c

   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  */