diff options
Diffstat (limited to 'arch/um/os-Linux/drivers/tuntap_user.c')
| -rw-r--r-- | arch/um/os-Linux/drivers/tuntap_user.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/arch/um/os-Linux/drivers/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c new file mode 100644 index 000000000..53eb3d508 --- /dev/null +++ b/arch/um/os-Linux/drivers/tuntap_user.c @@ -0,0 +1,215 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + */ + +#include <stdio.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> +#include <linux/if_tun.h> +#include <net/if.h> +#include <sys/ioctl.h> +#include <sys/socket.h> +#include <sys/wait.h> +#include <sys/uio.h> +#include <kern_util.h> +#include <os.h> +#include "tuntap.h" + +static int tuntap_user_init(void *data, void *dev) +{ + struct tuntap_data *pri = data; + + pri->dev = dev; + return 0; +} + +static void tuntap_add_addr(unsigned char *addr, unsigned char *netmask, + void *data) +{ + struct tuntap_data *pri = data; + + tap_check_ips(pri->gate_addr, addr); + if ((pri->fd == -1) || pri->fixed_config) + return; + open_addr(addr, netmask, pri->dev_name); +} + +static void tuntap_del_addr(unsigned char *addr, unsigned char *netmask, + void *data) +{ + struct tuntap_data *pri = data; + + if ((pri->fd == -1) || pri->fixed_config) + return; + close_addr(addr, netmask, pri->dev_name); +} + +struct tuntap_pre_exec_data { + int stdout_fd; + int close_me; +}; + +static void tuntap_pre_exec(void *arg) +{ + struct tuntap_pre_exec_data *data = arg; + + dup2(data->stdout_fd, 1); + close(data->close_me); +} + +static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote, + char *buffer, int buffer_len, int *used_out) +{ + struct tuntap_pre_exec_data data; + char version_buf[sizeof("nnnnn\0")]; + char *argv[] = { "uml_net", version_buf, "tuntap", "up", gate, + NULL }; + char buf[CMSG_SPACE(sizeof(*fd_out))]; + struct msghdr msg; + struct cmsghdr *cmsg; + struct iovec iov; + int pid, n, err; + + sprintf(version_buf, "%d", UML_NET_VERSION); + + data.stdout_fd = remote; + data.close_me = me; + + pid = run_helper(tuntap_pre_exec, &data, argv); + + if (pid < 0) + return pid; + + close(remote); + + msg.msg_name = NULL; + msg.msg_namelen = 0; + if (buffer != NULL) { + iov = ((struct iovec) { buffer, buffer_len }); + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + } + else { + msg.msg_iov = NULL; + msg.msg_iovlen = 0; + } + msg.msg_control = buf; + msg.msg_controllen = sizeof(buf); + msg.msg_flags = 0; + n = recvmsg(me, &msg, 0); + *used_out = n; + if (n < 0) { + err = -errno; + printk(UM_KERN_ERR "tuntap_open_tramp : recvmsg failed - " + "errno = %d\n", errno); + return err; + } + helper_wait(pid); + + cmsg = CMSG_FIRSTHDR(&msg); + if (cmsg == NULL) { + printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a " + "message\n"); + return -EINVAL; + } + if ((cmsg->cmsg_level != SOL_SOCKET) || + (cmsg->cmsg_type != SCM_RIGHTS)) { + printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a " + "descriptor\n"); + return -EINVAL; + } + *fd_out = ((int *) CMSG_DATA(cmsg))[0]; + os_set_exec_close(*fd_out); + return 0; +} + +static int tuntap_open(void *data) +{ + struct ifreq ifr; + struct tuntap_data *pri = data; + char *output, *buffer; + int err, fds[2], len, used; + + err = tap_open_common(pri->dev, pri->gate_addr); + if (err < 0) + return err; + + if (pri->fixed_config) { + pri->fd = os_open_file("/dev/net/tun", + of_cloexec(of_rdwr(OPENFLAGS())), 0); + if (pri->fd < 0) { + printk(UM_KERN_ERR "Failed to open /dev/net/tun, " + "err = %d\n", -pri->fd); + return pri->fd; + } + memset(&ifr, 0, sizeof(ifr)); + ifr.ifr_flags = IFF_TAP | IFF_NO_PI; + strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name)); + if (ioctl(pri->fd, TUNSETIFF, &ifr) < 0) { + err = -errno; + printk(UM_KERN_ERR "TUNSETIFF failed, errno = %d\n", + errno); + close(pri->fd); + return err; + } + } + else { + err = socketpair(AF_UNIX, SOCK_DGRAM, 0, fds); + if (err) { + err = -errno; + printk(UM_KERN_ERR "tuntap_open : socketpair failed - " + "errno = %d\n", errno); + return err; + } + + buffer = get_output_buffer(&len); + if (buffer != NULL) + len--; + used = 0; + + err = tuntap_open_tramp(pri->gate_addr, &pri->fd, fds[0], + fds[1], buffer, len, &used); + + output = buffer; + if (err < 0) { + printk("%s", output); + free_output_buffer(buffer); + printk(UM_KERN_ERR "tuntap_open_tramp failed - " + "err = %d\n", -err); + return err; + } + + pri->dev_name = uml_strdup(buffer); + output += IFNAMSIZ; + printk("%s", output); + free_output_buffer(buffer); + + close(fds[0]); + iter_addresses(pri->dev, open_addr, pri->dev_name); + } + + return pri->fd; +} + +static void tuntap_close(int fd, void *data) +{ + struct tuntap_data *pri = data; + + if (!pri->fixed_config) + iter_addresses(pri->dev, close_addr, pri->dev_name); + close(fd); + pri->fd = -1; +} + +const struct net_user_info tuntap_user_info = { + .init = tuntap_user_init, + .open = tuntap_open, + .close = tuntap_close, + .remove = NULL, + .add_address = tuntap_add_addr, + .delete_address = tuntap_del_addr, + .mtu = ETH_MAX_PACKET, + .max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER, +}; |