| /* |
| * 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_fd; |
| }; |
| |
| static void change_pre_exec(void *arg) |
| { |
| struct change_pre_exec_data *data = arg; |
| |
| close(data->close_me); |
| dup2(data->stdout_fd, 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_fd = 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; |
| } |