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/*
* Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/un.h>
#include "kern_constants.h"
#include "mconsole.h"
#include "user.h"
static struct mconsole_command commands[] = {
/*
* With uts namespaces, uts information becomes process-specific, so
* we need a process context. If we try handling this in interrupt
* context, we may hit an exiting process without a valid uts
* namespace.
*/
{ "version", mconsole_version, MCONSOLE_PROC },
{ "halt", mconsole_halt, MCONSOLE_PROC },
{ "reboot", mconsole_reboot, MCONSOLE_PROC },
{ "config", mconsole_config, MCONSOLE_PROC },
{ "remove", mconsole_remove, MCONSOLE_PROC },
{ "sysrq", mconsole_sysrq, MCONSOLE_INTR },
{ "help", mconsole_help, MCONSOLE_INTR },
{ "cad", mconsole_cad, MCONSOLE_INTR },
{ "stop", mconsole_stop, MCONSOLE_PROC },
{ "go", mconsole_go, MCONSOLE_INTR },
{ "log", mconsole_log, MCONSOLE_INTR },
{ "proc", mconsole_proc, MCONSOLE_PROC },
{ "stack", mconsole_stack, MCONSOLE_INTR },
};
/* Initialized in mconsole_init, which is an initcall */
char mconsole_socket_name[256];
int mconsole_reply_v0(struct mc_request *req, char *reply)
{
struct iovec iov;
struct msghdr msg;
iov.iov_base = reply;
iov.iov_len = strlen(reply);
msg.msg_name = &(req->origin);
msg.msg_namelen = req->originlen;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
return sendmsg(req->originating_fd, &msg, 0);
}
static struct mconsole_command *mconsole_parse(struct mc_request *req)
{
struct mconsole_command *cmd;
int i;
for (i = 0; i < ARRAY_SIZE(commands); i++) {
cmd = &commands[i];
if (!strncmp(req->request.data, cmd->command,
strlen(cmd->command))) {
return cmd;
}
}
return NULL;
}
#define MIN(a,b) ((a)<(b) ? (a):(b))
#define STRINGX(x) #x
#define STRING(x) STRINGX(x)
int mconsole_get_request(int fd, struct mc_request *req)
{
int len;
req->originlen = sizeof(req->origin);
req->len = recvfrom(fd, &req->request, sizeof(req->request),
MSG_DONTWAIT, (struct sockaddr *) req->origin,
&req->originlen);
if (req->len < 0)
return 0;
req->originating_fd = fd;
if (req->request.magic != MCONSOLE_MAGIC) {
/* Unversioned request */
len = MIN(sizeof(req->request.data) - 1,
strlen((char *) &req->request));
memmove(req->request.data, &req->request, len);
req->request.data[len] = '\0';
req->request.magic = MCONSOLE_MAGIC;
req->request.version = 0;
req->request.len = len;
mconsole_reply_v0(req, "ERR Version 0 mconsole clients are "
"not supported by this driver");
return 0;
}
if (req->request.len >= MCONSOLE_MAX_DATA) {
mconsole_reply(req, "Request too large", 1, 0);
return 0;
}
if (req->request.version != MCONSOLE_VERSION) {
mconsole_reply(req, "This driver only supports version "
STRING(MCONSOLE_VERSION) " clients", 1, 0);
}
req->request.data[req->request.len] = '\0';
req->cmd = mconsole_parse(req);
if (req->cmd == NULL) {
mconsole_reply(req, "Unknown command", 1, 0);
return 0;
}
return 1;
}
int mconsole_reply_len(struct mc_request *req, const char *str, int total,
int err, int more)
{
/*
* XXX This is a stack consumption problem. It'd be nice to
* make it global and serialize access to it, but there are a
* ton of callers to this function.
*/
struct mconsole_reply reply;
int len, n;
do {
reply.err = err;
/* err can only be true on the first packet */
err = 0;
len = MIN(total, MCONSOLE_MAX_DATA - 1);
if (len == total) reply.more = more;
else reply.more = 1;
memcpy(reply.data, str, len);
reply.data[len] = '\0';
total -= len;
str += len;
reply.len = len + 1;
len = sizeof(reply) + reply.len - sizeof(reply.data);
n = sendto(req->originating_fd, &reply, len, 0,
(struct sockaddr *) req->origin, req->originlen);
if (n < 0)
return -errno;
} while (total > 0);
return 0;
}
int mconsole_reply(struct mc_request *req, const char *str, int err, int more)
{
return mconsole_reply_len(req, str, strlen(str), err, more);
}
int mconsole_unlink_socket(void)
{
unlink(mconsole_socket_name);
return 0;
}
static int notify_sock = -1;
int mconsole_notify(char *sock_name, int type, const void *data, int len)
{
struct sockaddr_un target;
struct mconsole_notify packet;
int n, err = 0;
lock_notify();
if (notify_sock < 0) {
notify_sock = socket(PF_UNIX, SOCK_DGRAM, 0);
if (notify_sock < 0) {
err = -errno;
printk(UM_KERN_ERR "mconsole_notify - socket failed, "
"errno = %d\n", errno);
}
}
unlock_notify();
if (err)
return err;
target.sun_family = AF_UNIX;
strcpy(target.sun_path, sock_name);
packet.magic = MCONSOLE_MAGIC;
packet.version = MCONSOLE_VERSION;
packet.type = type;
len = (len > sizeof(packet.data)) ? sizeof(packet.data) : len;
packet.len = len;
memcpy(packet.data, data, len);
err = 0;
len = sizeof(packet) + packet.len - sizeof(packet.data);
n = sendto(notify_sock, &packet, len, 0, (struct sockaddr *) &target,
sizeof(target));
if (n < 0) {
err = -errno;
printk(UM_KERN_ERR "mconsole_notify - sendto failed, "
"errno = %d\n", errno);
}
return err;
}
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