Fixed MTP to work with TWRP

arch/um/drivers/net_user.c

@@ -0,0 +1,269 @@
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <stddef.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <net_user.h>
+#include <os.h>
+#include <um_malloc.h>
+
+int tap_open_common(void *dev, char *gate_addr)
+{
+	int tap_addr[4];
+
+	if (gate_addr == NULL)
+		return 0;
+	if (sscanf(gate_addr, "%d.%d.%d.%d", &tap_addr[0],
+		  &tap_addr[1], &tap_addr[2], &tap_addr[3]) != 4) {
+		printk(UM_KERN_ERR "Invalid tap IP address - '%s'\n",
+		       gate_addr);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+void tap_check_ips(char *gate_addr, unsigned char *eth_addr)
+{
+	int tap_addr[4];
+
+	if ((gate_addr != NULL) &&
+	    (sscanf(gate_addr, "%d.%d.%d.%d", &tap_addr[0],
+		    &tap_addr[1], &tap_addr[2], &tap_addr[3]) == 4) &&
+	    (eth_addr[0] == tap_addr[0]) &&
+	    (eth_addr[1] == tap_addr[1]) &&
+	    (eth_addr[2] == tap_addr[2]) &&
+	    (eth_addr[3] == tap_addr[3])) {
+		printk(UM_KERN_ERR "The tap IP address and the UML eth IP "
+		       "address must be different\n");
+	}
+}
+
+/* Do reliable error handling as this fails frequently enough. */
+void read_output(int fd, char *output, int len)
+{
+	int remain, ret, expected;
+	char c;
+	char *str;
+
+	if (output == NULL) {
+		output = &c;
+		len = sizeof(c);
+	}
+
+	*output = '\0';
+	ret = read(fd, &remain, sizeof(remain));
+
+	if (ret != sizeof(remain)) {
+		if (ret < 0)
+			ret = -errno;
+		expected = sizeof(remain);
+		str = "length";
+		goto err;
+	}
+
+	while (remain != 0) {
+		expected = (remain < len) ? remain : len;
+		ret = read(fd, output, expected);
+		if (ret != expected) {
+			if (ret < 0)
+				ret = -errno;
+			str = "data";
+			goto err;
+		}
+		remain -= ret;
+	}
+
+	return;
+
+err:
+	if (ret < 0)
+		printk(UM_KERN_ERR "read_output - read of %s failed, "
+		       "errno = %d\n", str, -ret);
+	else
+		printk(UM_KERN_ERR "read_output - read of %s failed, read only "
+		       "%d of %d bytes\n", str, ret, expected);
+}
+
+int net_read(int fd, void *buf, int len)
+{
+	int n;
+
+	n = read(fd,  buf,  len);
+
+	if ((n < 0) && (errno == EAGAIN))
+		return 0;
+	else if (n == 0)
+		return -ENOTCONN;
+	return n;
+}
+
+int net_recvfrom(int fd, void *buf, int len)
+{
+	int n;
+
+	CATCH_EINTR(n = recvfrom(fd,  buf,  len, 0, NULL, NULL));
+	if (n < 0) {
+		if (errno == EAGAIN)
+			return 0;
+		return -errno;
+	}
+	else if (n == 0)
+		return -ENOTCONN;
+	return n;
+}
+
+int net_write(int fd, void *buf, int len)
+{
+	int n;
+
+	n = write(fd, buf, len);
+
+	if ((n < 0) && (errno == EAGAIN))
+		return 0;
+	else if (n == 0)
+		return -ENOTCONN;
+	return n;
+}
+
+int net_send(int fd, void *buf, int len)
+{
+	int n;
+
+	CATCH_EINTR(n = send(fd, buf, len, 0));
+	if (n < 0) {
+		if (errno == EAGAIN)
+			return 0;
+		return -errno;
+	}
+	else if (n == 0)
+		return -ENOTCONN;
+	return n;
+}
+
+int net_sendto(int fd, void *buf, int len, void *to, int sock_len)
+{
+	int n;
+
+	CATCH_EINTR(n = sendto(fd, buf, len, 0, (struct sockaddr *) to,
+			       sock_len));
+	if (n < 0) {
+		if (errno == EAGAIN)
+			return 0;
+		return -errno;
+	}
+	else if (n == 0)
+		return -ENOTCONN;
+	return n;
+}
+
+struct change_pre_exec_data {
+	int close_me;
+	int stdout;
+};
+
+static void change_pre_exec(void *arg)
+{
+	struct change_pre_exec_data *data = arg;
+
+	close(data->close_me);
+	dup2(data->stdout, 1);
+}
+
+static int change_tramp(char **argv, char *output, int output_len)
+{
+	int pid, fds[2], err;
+	struct change_pre_exec_data pe_data;
+
+	err = os_pipe(fds, 1, 0);
+	if (err < 0) {
+		printk(UM_KERN_ERR "change_tramp - pipe failed, err = %d\n",
+		       -err);
+		return err;
+	}
+	pe_data.close_me = fds[0];
+	pe_data.stdout = fds[1];
+	pid = run_helper(change_pre_exec, &pe_data, argv);
+
+	if (pid > 0)	/* Avoid hang as we won't get data in failure case. */
+		read_output(fds[0], output, output_len);
+
+	close(fds[0]);
+	close(fds[1]);
+
+	if (pid > 0)
+		helper_wait(pid);
+	return pid;
+}
+
+static void change(char *dev, char *what, unsigned char *addr,
+		   unsigned char *netmask)
+{
+	char addr_buf[sizeof("255.255.255.255\0")];
+	char netmask_buf[sizeof("255.255.255.255\0")];
+	char version[sizeof("nnnnn\0")];
+	char *argv[] = { "uml_net", version, what, dev, addr_buf,
+			 netmask_buf, NULL };
+	char *output;
+	int output_len, pid;
+
+	sprintf(version, "%d", UML_NET_VERSION);
+	sprintf(addr_buf, "%d.%d.%d.%d", addr[0], addr[1], addr[2], addr[3]);
+	sprintf(netmask_buf, "%d.%d.%d.%d", netmask[0], netmask[1],
+		netmask[2], netmask[3]);
+
+	output_len = UM_KERN_PAGE_SIZE;
+	output = uml_kmalloc(output_len, UM_GFP_KERNEL);
+	if (output == NULL)
+		printk(UM_KERN_ERR "change : failed to allocate output "
+		       "buffer\n");
+
+	pid = change_tramp(argv, output, output_len);
+	if (pid < 0) {
+		kfree(output);
+		return;
+	}
+
+	if (output != NULL) {
+		printk("%s", output);
+		kfree(output);
+	}
+}
+
+void open_addr(unsigned char *addr, unsigned char *netmask, void *arg)
+{
+	change(arg, "add", addr, netmask);
+}
+
+void close_addr(unsigned char *addr, unsigned char *netmask, void *arg)
+{
+	change(arg, "del", addr, netmask);
+}
+
+char *split_if_spec(char *str, ...)
+{
+	char **arg, *end;
+	va_list ap;
+
+	va_start(ap, str);
+	while ((arg = va_arg(ap, char **)) != NULL) {
+		if (*str == '\0')
+			return NULL;
+		end = strchr(str, ',');
+		if (end != str)
+			*arg = str;
+		if (end == NULL)
+			return NULL;
+		*end++ = '\0';
+		str = end;
+	}
+	va_end(ap);
+	return str;
+}