diff options
Diffstat (limited to 'arch/um/drivers/net_user.c')
| -rw-r--r-- | arch/um/drivers/net_user.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/arch/um/drivers/net_user.c b/arch/um/drivers/net_user.c new file mode 100644 index 0000000000..4c9576452a --- /dev/null +++ b/arch/um/drivers/net_user.c @@ -0,0 +1,271 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + */ + +#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, *ret = NULL; + va_list ap; + + va_start(ap, str); + while ((arg = va_arg(ap, char **)) != NULL) { + if (*str == '\0') + goto out; + end = strchr(str, ','); + if (end != str) + *arg = str; + if (end == NULL) + goto out; + *end++ = '\0'; + str = end; + } + ret = str; +out: + va_end(ap); + return ret; +} |