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 "sysdep/ptrace.h" 18 #include "mconsole.h" 19 #include "os.h" 20 21 static struct mconsole_command commands[] = { 22 /* With uts namespaces, uts information becomes process-specific, so 23 * we need a process context. If we try handling this in interrupt 24 * context, we may hit an exiting process without a valid uts 25 * namespace. 26 */ 27 { "version", mconsole_version, MCONSOLE_PROC }, 28 { "halt", mconsole_halt, MCONSOLE_PROC }, 29 { "reboot", mconsole_reboot, MCONSOLE_PROC }, 30 { "config", mconsole_config, MCONSOLE_PROC }, 31 { "remove", mconsole_remove, MCONSOLE_PROC }, 32 { "sysrq", mconsole_sysrq, MCONSOLE_INTR }, 33 { "help", mconsole_help, MCONSOLE_INTR }, 34 { "cad", mconsole_cad, MCONSOLE_INTR }, 35 { "stop", mconsole_stop, MCONSOLE_PROC }, 36 { "go", mconsole_go, MCONSOLE_INTR }, 37 { "log", mconsole_log, MCONSOLE_INTR }, 38 { "proc", mconsole_proc, MCONSOLE_PROC }, 39 { "stack", mconsole_stack, MCONSOLE_INTR }, 40 }; 41 42 /* Initialized in mconsole_init, which is an initcall */ 43 char mconsole_socket_name[256]; 44 45 int mconsole_reply_v0(struct mc_request *req, char *reply) 46 { 47 struct iovec iov; 48 struct msghdr msg; 49 50 iov.iov_base = reply; 51 iov.iov_len = strlen(reply); 52 53 msg.msg_name = &(req->origin); 54 msg.msg_namelen = req->originlen; 55 msg.msg_iov = &iov; 56 msg.msg_iovlen = 1; 57 msg.msg_control = NULL; 58 msg.msg_controllen = 0; 59 msg.msg_flags = 0; 60 61 return sendmsg(req->originating_fd, &msg, 0); 62 } 63 64 static struct mconsole_command *mconsole_parse(struct mc_request *req) 65 { 66 struct mconsole_command *cmd; 67 int i; 68 69 for(i = 0; i < ARRAY_SIZE(commands); i++){ 70 cmd = &commands[i]; 71 if(!strncmp(req->request.data, cmd->command, 72 strlen(cmd->command))){ 73 return cmd; 74 } 75 } 76 return NULL; 77 } 78 79 #define MIN(a,b) ((a)<(b) ? (a):(b)) 80 81 #define STRINGX(x) #x 82 #define STRING(x) STRINGX(x) 83 84 int mconsole_get_request(int fd, struct mc_request *req) 85 { 86 int len; 87 88 req->originlen = sizeof(req->origin); 89 req->len = recvfrom(fd, &req->request, sizeof(req->request), 90 MSG_DONTWAIT, (struct sockaddr *) req->origin, 91 &req->originlen); 92 if (req->len < 0) 93 return 0; 94 95 req->originating_fd = fd; 96 97 if(req->request.magic != MCONSOLE_MAGIC){ 98 /* Unversioned request */ 99 len = MIN(sizeof(req->request.data) - 1, 100 strlen((char *) &req->request)); 101 memmove(req->request.data, &req->request, len); 102 req->request.data[len] = '\0'; 103 104 req->request.magic = MCONSOLE_MAGIC; 105 req->request.version = 0; 106 req->request.len = len; 107 108 mconsole_reply_v0(req, "ERR Version 0 mconsole clients are " 109 "not supported by this driver"); 110 return(0); 111 } 112 113 if(req->request.len >= MCONSOLE_MAX_DATA){ 114 mconsole_reply(req, "Request too large", 1, 0); 115 return(0); 116 } 117 if(req->request.version != MCONSOLE_VERSION){ 118 mconsole_reply(req, "This driver only supports version " 119 STRING(MCONSOLE_VERSION) " clients", 1, 0); 120 } 121 122 req->request.data[req->request.len] = '\0'; 123 req->cmd = mconsole_parse(req); 124 if(req->cmd == NULL){ 125 mconsole_reply(req, "Unknown command", 1, 0); 126 return(0); 127 } 128 129 return(1); 130 } 131 132 int mconsole_reply_len(struct mc_request *req, const char *str, int total, 133 int err, int more) 134 { 135 /* XXX This is a stack consumption problem. It'd be nice to 136 * make it global and serialize access to it, but there are a 137 * ton of callers to this function. 138 */ 139 struct mconsole_reply reply; 140 int len, n; 141 142 do { 143 reply.err = err; 144 145 /* err can only be true on the first packet */ 146 err = 0; 147 148 len = MIN(total, MCONSOLE_MAX_DATA - 1); 149 150 if(len == total) reply.more = more; 151 else reply.more = 1; 152 153 memcpy(reply.data, str, len); 154 reply.data[len] = '\0'; 155 total -= len; 156 str += len; 157 reply.len = len + 1; 158 159 len = sizeof(reply) + reply.len - sizeof(reply.data); 160 161 n = sendto(req->originating_fd, &reply, len, 0, 162 (struct sockaddr *) req->origin, req->originlen); 163 164 if(n < 0) return(-errno); 165 } while(total > 0); 166 return(0); 167 } 168 169 int mconsole_reply(struct mc_request *req, const char *str, int err, int more) 170 { 171 return mconsole_reply_len(req, str, strlen(str), err, more); 172 } 173 174 175 int mconsole_unlink_socket(void) 176 { 177 unlink(mconsole_socket_name); 178 return 0; 179 } 180 181 static int notify_sock = -1; 182 183 int mconsole_notify(char *sock_name, int type, const void *data, int len) 184 { 185 struct sockaddr_un target; 186 struct mconsole_notify packet; 187 int n, err = 0; 188 189 lock_notify(); 190 if(notify_sock < 0){ 191 notify_sock = socket(PF_UNIX, SOCK_DGRAM, 0); 192 if(notify_sock < 0){ 193 err = -errno; 194 printk("mconsole_notify - socket failed, errno = %d\n", 195 err); 196 } 197 } 198 unlock_notify(); 199 200 if(err) 201 return(err); 202 203 target.sun_family = AF_UNIX; 204 strcpy(target.sun_path, sock_name); 205 206 packet.magic = MCONSOLE_MAGIC; 207 packet.version = MCONSOLE_VERSION; 208 packet.type = type; 209 len = (len > sizeof(packet.data)) ? sizeof(packet.data) : len; 210 packet.len = len; 211 memcpy(packet.data, data, len); 212 213 err = 0; 214 len = sizeof(packet) + packet.len - sizeof(packet.data); 215 n = sendto(notify_sock, &packet, len, 0, (struct sockaddr *) &target, 216 sizeof(target)); 217 if(n < 0){ 218 err = -errno; 219 printk("mconsole_notify - sendto failed, errno = %d\n", errno); 220 } 221 return(err); 222 } 223 224 /* 225 * Overrides for Emacs so that we follow Linus's tabbing style. 226 * Emacs will notice this stuff at the end of the file and automatically 227 * adjust the settings for this buffer only. This must remain at the end 228 * of the file. 229 * --------------------------------------------------------------------------- 230 * Local variables: 231 * c-file-style: "linux" 232 * End: 233 */ 234