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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 | /* * NETLINK An implementation of a loadable kernel mode driver providing * multiple kernel/user space bidirectional communications links. * * Author: Alan Cox <alan@redhat.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * Now netlink devices are emulated on the top of netlink sockets * by compatibility reasons. Remove this file after a period. --ANK * */ #include <linux/module.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/major.h> #include <linux/sched.h> #include <linux/malloc.h> #include <linux/skbuff.h> #include <linux/netlink.h> #include <linux/poll.h> #include <linux/init.h> #include <linux/devfs_fs_kernel.h> #include <asm/system.h> #include <asm/uaccess.h> static unsigned open_map = 0; static struct socket *netlink_user[MAX_LINKS]; /* * Device operations */ static unsigned int netlink_poll(struct file *file, poll_table * wait) { struct socket *sock = netlink_user[MINOR(file->f_dentry->d_inode->i_rdev)]; if (sock->ops->poll==NULL) return 0; return sock->ops->poll(file, sock, wait); } /* * Write a message to the kernel side of a communication link */ static ssize_t netlink_write(struct file * file, const char * buf, size_t count, loff_t *pos) { struct inode *inode = file->f_dentry->d_inode; struct socket *sock = netlink_user[MINOR(inode->i_rdev)]; struct msghdr msg; struct iovec iov; iov.iov_base = (void*)buf; iov.iov_len = count; msg.msg_name=NULL; msg.msg_namelen=0; msg.msg_controllen=0; msg.msg_flags=0; msg.msg_iov=&iov; msg.msg_iovlen=1; return sock_sendmsg(sock, &msg, count); } /* * Read a message from the kernel side of the communication link */ static ssize_t netlink_read(struct file * file, char * buf, size_t count, loff_t *pos) { struct inode *inode = file->f_dentry->d_inode; struct socket *sock = netlink_user[MINOR(inode->i_rdev)]; struct msghdr msg; struct iovec iov; iov.iov_base = buf; iov.iov_len = count; msg.msg_name=NULL; msg.msg_namelen=0; msg.msg_controllen=0; msg.msg_flags=0; msg.msg_iov=&iov; msg.msg_iovlen=1; if (file->f_flags&O_NONBLOCK) msg.msg_flags=MSG_DONTWAIT; return sock_recvmsg(sock, &msg, count, msg.msg_flags); } static loff_t netlink_lseek(struct file * file, loff_t offset, int origin) { return -ESPIPE; } static int netlink_open(struct inode * inode, struct file * file) { unsigned int minor = MINOR(inode->i_rdev); struct socket *sock; struct sockaddr_nl nladdr; int err; if (minor>=MAX_LINKS) return -ENODEV; if (open_map&(1<<minor)) return -EBUSY; open_map |= (1<<minor); MOD_INC_USE_COUNT; err = sock_create(PF_NETLINK, SOCK_RAW, minor, &sock); if (err < 0) goto out; memset(&nladdr, 0, sizeof(nladdr)); nladdr.nl_family = AF_NETLINK; nladdr.nl_groups = ~0; if ((err = sock->ops->bind(sock, (struct sockaddr*)&nladdr, sizeof(nladdr))) < 0) { sock_release(sock); goto out; } netlink_user[minor] = sock; return 0; out: open_map &= ~(1<<minor); MOD_DEC_USE_COUNT; return err; } static int netlink_release(struct inode * inode, struct file * file) { unsigned int minor = MINOR(inode->i_rdev); struct socket *sock = netlink_user[minor]; netlink_user[minor] = NULL; open_map &= ~(1<<minor); sock_release(sock); MOD_DEC_USE_COUNT; return 0; } static int netlink_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { unsigned int minor = MINOR(inode->i_rdev); int retval = 0; if (minor >= MAX_LINKS) return -ENODEV; switch ( cmd ) { default: retval = -EINVAL; } return retval; } static struct file_operations netlink_fops = { llseek: netlink_lseek, read: netlink_read, write: netlink_write, poll: netlink_poll, ioctl: netlink_ioctl, open: netlink_open, release: netlink_release, }; static devfs_handle_t devfs_handle = NULL; static void __init make_devfs_entries (const char *name, int minor) { devfs_register (devfs_handle, name, 0, DEVFS_FL_DEFAULT, NETLINK_MAJOR, minor, S_IFCHR | S_IRUSR | S_IWUSR, 0, 0, &netlink_fops, NULL); } int __init init_netlink(void) { if (devfs_register_chrdev(NETLINK_MAJOR,"netlink", &netlink_fops)) { printk(KERN_ERR "netlink: unable to get major %d\n", NETLINK_MAJOR); return -EIO; } devfs_handle = devfs_mk_dir (NULL, "netlink", 7, NULL); /* Someone tell me the official names for the uppercase ones */ make_devfs_entries ("route", 0); make_devfs_entries ("skip", 1); make_devfs_entries ("USERSOCK", 2); make_devfs_entries ("fwmonitor", 3); make_devfs_entries ("ARPD", 8); make_devfs_entries ("ROUTE6", 11); make_devfs_entries ("IP6_FW", 13); devfs_register_series (devfs_handle, "tap%u", 16, DEVFS_FL_DEFAULT, NETLINK_MAJOR, 16, S_IFCHR | S_IRUSR | S_IWUSR, 0, 0, &netlink_fops, NULL); return 0; } #ifdef MODULE int init_module(void) { printk(KERN_INFO "Network Kernel/User communications module 0.04\n"); return init_netlink(); } void cleanup_module(void) { devfs_unregister (devfs_handle); devfs_unregister_chrdev(NETLINK_MAJOR, "netlink"); } #endif |