Fixed MTP to work with TWRP

arch/um/drivers/mconsole_user.c

@@ -0,0 +1,219 @@
+/*
+ * 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 "mconsole.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];
+
+static 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), 0,
+			    (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;
+}