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         { "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  */