1 /* 2 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) 3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 4 * Licensed under the GPL 5 */ 6 7 #include <errno.h> 8 #include <string.h> 9 #include <unistd.h> 10 #include <sys/socket.h> 11 #include <sys/uio.h> 12 #include <sys/un.h> 13 #include "kern_constants.h" 14 #include "mconsole.h" 15 #include "user.h" 16 17 static struct mconsole_command commands[] = { 18 /* 19 * With uts namespaces, uts information becomes process-specific, so 20 * we need a process context. If we try handling this in interrupt 21 * context, we may hit an exiting process without a valid uts 22 * namespace. 23 */ 24 { "version", mconsole_version, MCONSOLE_PROC }, 25 { "halt", mconsole_halt, MCONSOLE_PROC }, 26 { "reboot", mconsole_reboot, MCONSOLE_PROC }, 27 { "config", mconsole_config, MCONSOLE_PROC }, 28 { "remove", mconsole_remove, MCONSOLE_PROC }, 29 { "sysrq", mconsole_sysrq, MCONSOLE_INTR }, 30 { "help", mconsole_help, MCONSOLE_INTR }, 31 { "cad", mconsole_cad, MCONSOLE_INTR }, 32 { "stop", mconsole_stop, MCONSOLE_PROC }, 33 { "go", mconsole_go, MCONSOLE_INTR }, 34 { "log", mconsole_log, MCONSOLE_INTR }, 35 { "proc", mconsole_proc, MCONSOLE_PROC }, 36 { "stack", mconsole_stack, MCONSOLE_INTR }, 37 }; 38 39 /* Initialized in mconsole_init, which is an initcall */ 40 char mconsole_socket_name[256]; 41 42 int mconsole_reply_v0(struct mc_request *req, char *reply) 43 { 44 struct iovec iov; 45 struct msghdr msg; 46 47 iov.iov_base = reply; 48 iov.iov_len = strlen(reply); 49 50 msg.msg_name = &(req->origin); 51 msg.msg_namelen = req->originlen; 52 msg.msg_iov = &iov; 53 msg.msg_iovlen = 1; 54 msg.msg_control = NULL; 55 msg.msg_controllen = 0; 56 msg.msg_flags = 0; 57 58 return sendmsg(req->originating_fd, &msg, 0); 59 } 60 61 static struct mconsole_command *mconsole_parse(struct mc_request *req) 62 { 63 struct mconsole_command *cmd; 64 int i; 65 66 for (i = 0; i < ARRAY_SIZE(commands); i++) { 67 cmd = &commands[i]; 68 if (!strncmp(req->request.data, cmd->command, 69 strlen(cmd->command))) { 70 return cmd; 71 } 72 } 73 return NULL; 74 } 75 76 #define MIN(a,b) ((a)<(b) ? (a):(b)) 77 78 #define STRINGX(x) #x 79 #define STRING(x) STRINGX(x) 80 81 int mconsole_get_request(int fd, struct mc_request *req) 82 { 83 int len; 84 85 req->originlen = sizeof(req->origin); 86 req->len = recvfrom(fd, &req->request, sizeof(req->request), 87 MSG_DONTWAIT, (struct sockaddr *) req->origin, 88 &req->originlen); 89 if (req->len < 0) 90 return 0; 91 92 req->originating_fd = fd; 93 94 if (req->request.magic != MCONSOLE_MAGIC) { 95 /* Unversioned request */ 96 len = MIN(sizeof(req->request.data) - 1, 97 strlen((char *) &req->request)); 98 memmove(req->request.data, &req->request, len); 99 req->request.data[len] = '\0'; 100 101 req->request.magic = MCONSOLE_MAGIC; 102 req->request.version = 0; 103 req->request.len = len; 104 105 mconsole_reply_v0(req, "ERR Version 0 mconsole clients are " 106 "not supported by this driver"); 107 return 0; 108 } 109 110 if (req->request.len >= MCONSOLE_MAX_DATA) { 111 mconsole_reply(req, "Request too large", 1, 0); 112 return 0; 113 } 114 if (req->request.version != MCONSOLE_VERSION) { 115 mconsole_reply(req, "This driver only supports version " 116 STRING(MCONSOLE_VERSION) " clients", 1, 0); 117 } 118 119 req->request.data[req->request.len] = '\0'; 120 req->cmd = mconsole_parse(req); 121 if (req->cmd == NULL) { 122 mconsole_reply(req, "Unknown command", 1, 0); 123 return 0; 124 } 125 126 return 1; 127 } 128 129 int mconsole_reply_len(struct mc_request *req, const char *str, int total, 130 int err, int more) 131 { 132 /* 133 * XXX This is a stack consumption problem. It'd be nice to 134 * make it global and serialize access to it, but there are a 135 * ton of callers to this function. 136 */ 137 struct mconsole_reply reply; 138 int len, n; 139 140 do { 141 reply.err = err; 142 143 /* err can only be true on the first packet */ 144 err = 0; 145 146 len = MIN(total, MCONSOLE_MAX_DATA - 1); 147 148 if (len == total) reply.more = more; 149 else reply.more = 1; 150 151 memcpy(reply.data, str, len); 152 reply.data[len] = '\0'; 153 total -= len; 154 str += len; 155 reply.len = len + 1; 156 157 len = sizeof(reply) + reply.len - sizeof(reply.data); 158 159 n = sendto(req->originating_fd, &reply, len, 0, 160 (struct sockaddr *) req->origin, req->originlen); 161 162 if (n < 0) 163 return -errno; 164 } while (total > 0); 165 return 0; 166 } 167 168 int mconsole_reply(struct mc_request *req, const char *str, int err, int more) 169 { 170 return mconsole_reply_len(req, str, strlen(str), err, more); 171 } 172 173 174 int mconsole_unlink_socket(void) 175 { 176 unlink(mconsole_socket_name); 177 return 0; 178 } 179 180 static int notify_sock = -1; 181 182 int mconsole_notify(char *sock_name, int type, const void *data, int len) 183 { 184 struct sockaddr_un target; 185 struct mconsole_notify packet; 186 int n, err = 0; 187 188 lock_notify(); 189 if (notify_sock < 0) { 190 notify_sock = socket(PF_UNIX, SOCK_DGRAM, 0); 191 if (notify_sock < 0) { 192 err = -errno; 193 printk(UM_KERN_ERR "mconsole_notify - socket failed, " 194 "errno = %d\n", errno); 195 } 196 } 197 unlock_notify(); 198 199 if (err) 200 return err; 201 202 target.sun_family = AF_UNIX; 203 strcpy(target.sun_path, sock_name); 204 205 packet.magic = MCONSOLE_MAGIC; 206 packet.version = MCONSOLE_VERSION; 207 packet.type = type; 208 len = (len > sizeof(packet.data)) ? sizeof(packet.data) : len; 209 packet.len = len; 210 memcpy(packet.data, data, len); 211 212 err = 0; 213 len = sizeof(packet) + packet.len - sizeof(packet.data); 214 n = sendto(notify_sock, &packet, len, 0, (struct sockaddr *) &target, 215 sizeof(target)); 216 if (n < 0) { 217 err = -errno; 218 printk(UM_KERN_ERR "mconsole_notify - sendto failed, " 219 "errno = %d\n", errno); 220 } 221 return err; 222 } 223