LXR linux/include/linux/netlink.h

   1#ifndef __LINUX_NETLINK_H
   2#define __LINUX_NETLINK_H
   3
   4#include <linux/socket.h> /* for sa_family_t */
   5#include <linux/types.h>
   6
   7#define NETLINK_ROUTE           0       /* Routing/device hook                          */
   8#define NETLINK_UNUSED          1       /* Unused number                                */
   9#define NETLINK_USERSOCK        2       /* Reserved for user mode socket protocols      */
  10#define NETLINK_FIREWALL        3       /* Firewalling hook                             */
  11#define NETLINK_INET_DIAG       4       /* INET socket monitoring                       */
  12#define NETLINK_NFLOG           5       /* netfilter/iptables ULOG */
  13#define NETLINK_XFRM            6       /* ipsec */
  14#define NETLINK_SELINUX         7       /* SELinux event notifications */
  15#define NETLINK_ISCSI           8       /* Open-iSCSI */
  16#define NETLINK_AUDIT           9       /* auditing */
  17#define NETLINK_FIB_LOOKUP      10      
  18#define NETLINK_CONNECTOR       11
  19#define NETLINK_NETFILTER       12      /* netfilter subsystem */
  20#define NETLINK_IP6_FW          13
  21#define NETLINK_DNRTMSG         14      /* DECnet routing messages */
  22#define NETLINK_KOBJECT_UEVENT  15      /* Kernel messages to userspace */
  23#define NETLINK_GENERIC         16
  24/* leave room for NETLINK_DM (DM Events) */
  25#define NETLINK_SCSITRANSPORT   18      /* SCSI Transports */
  26#define NETLINK_ECRYPTFS        19
  27
  28#define MAX_LINKS 32            
  29
  30struct sockaddr_nl {
  31        sa_family_t     nl_family;      /* AF_NETLINK   */
  32        unsigned short  nl_pad;         /* zero         */
  33        __u32           nl_pid;         /* port ID      */
  34        __u32           nl_groups;      /* multicast groups mask */
  35};
  36
  37struct nlmsghdr {
  38        __u32           nlmsg_len;      /* Length of message including header */
  39        __u16           nlmsg_type;     /* Message content */
  40        __u16           nlmsg_flags;    /* Additional flags */
  41        __u32           nlmsg_seq;      /* Sequence number */
  42        __u32           nlmsg_pid;      /* Sending process port ID */
  43};
  44
  45/* Flags values */
  46
  47#define NLM_F_REQUEST           1       /* It is request message.       */
  48#define NLM_F_MULTI             2       /* Multipart message, terminated by NLMSG_DONE */
  49#define NLM_F_ACK               4       /* Reply with ack, with zero or error code */
  50#define NLM_F_ECHO              8       /* Echo this request            */
  51
  52/* Modifiers to GET request */
  53#define NLM_F_ROOT      0x100   /* specify tree root    */
  54#define NLM_F_MATCH     0x200   /* return all matching  */
  55#define NLM_F_ATOMIC    0x400   /* atomic GET           */
  56#define NLM_F_DUMP      (NLM_F_ROOT|NLM_F_MATCH)
  57
  58/* Modifiers to NEW request */
  59#define NLM_F_REPLACE   0x100   /* Override existing            */
  60#define NLM_F_EXCL      0x200   /* Do not touch, if it exists   */
  61#define NLM_F_CREATE    0x400   /* Create, if it does not exist */
  62#define NLM_F_APPEND    0x800   /* Add to end of list           */
  63
  64/*
  65   4.4BSD ADD           NLM_F_CREATE|NLM_F_EXCL
  66   4.4BSD CHANGE        NLM_F_REPLACE
  67
  68   True CHANGE          NLM_F_CREATE|NLM_F_REPLACE
  69   Append               NLM_F_CREATE
  70   Check                NLM_F_EXCL
  71 */
  72
  73#define NLMSG_ALIGNTO   4U
  74#define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )
  75#define NLMSG_HDRLEN     ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
  76#define NLMSG_LENGTH(len) ((len)+NLMSG_ALIGN(NLMSG_HDRLEN))
  77#define NLMSG_SPACE(len) NLMSG_ALIGN(NLMSG_LENGTH(len))
  78#define NLMSG_DATA(nlh)  ((void*)(((char*)nlh) + NLMSG_LENGTH(0)))
  79#define NLMSG_NEXT(nlh,len)      ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
  80                                  (struct nlmsghdr*)(((char*)(nlh)) + NLMSG_ALIGN((nlh)->nlmsg_len)))
  81#define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
  82                           (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
  83                           (nlh)->nlmsg_len <= (len))
  84#define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))
  85
  86#define NLMSG_NOOP              0x1     /* Nothing.             */
  87#define NLMSG_ERROR             0x2     /* Error                */
  88#define NLMSG_DONE              0x3     /* End of a dump        */
  89#define NLMSG_OVERRUN           0x4     /* Data lost            */
  90
  91#define NLMSG_MIN_TYPE          0x10    /* < 0x10: reserved control messages */
  92
  93struct nlmsgerr {
  94        int             error;
  95        struct nlmsghdr msg;
  96};
  97
  98#define NETLINK_ADD_MEMBERSHIP  1
  99#define NETLINK_DROP_MEMBERSHIP 2
 100#define NETLINK_PKTINFO         3
 101#define NETLINK_BROADCAST_ERROR 4
 102#define NETLINK_NO_ENOBUFS      5
 103
 104struct nl_pktinfo {
 105        __u32   group;
 106};
 107
 108#define NET_MAJOR 36            /* Major 36 is reserved for networking                                          */
 109
 110enum {
 111        NETLINK_UNCONNECTED = 0,
 112        NETLINK_CONNECTED,
 113};
 114
 115/*
 116 *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
 117 * +---------------------+- - -+- - - - - - - - - -+- - -+
 118 * |        Header       | Pad |     Payload       | Pad |
 119 * |   (struct nlattr)   | ing |                   | ing |
 120 * +---------------------+- - -+- - - - - - - - - -+- - -+
 121 *  <-------------- nlattr->nla_len -------------->
 122 */
 123
 124struct nlattr {
 125        __u16           nla_len;
 126        __u16           nla_type;
 127};
 128
 129/*
 130 * nla_type (16 bits)
 131 * +---+---+-------------------------------+
 132 * | N | O | Attribute Type                |
 133 * +---+---+-------------------------------+
 134 * N := Carries nested attributes
 135 * O := Payload stored in network byte order
 136 *
 137 * Note: The N and O flag are mutually exclusive.
 138 */
 139#define NLA_F_NESTED            (1 << 15)
 140#define NLA_F_NET_BYTEORDER     (1 << 14)
 141#define NLA_TYPE_MASK           ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
 142
 143#define NLA_ALIGNTO             4
 144#define NLA_ALIGN(len)          (((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
 145#define NLA_HDRLEN              ((int) NLA_ALIGN(sizeof(struct nlattr)))
 146
 147#ifdef __KERNEL__
 148
 149#include <linux/capability.h>
 150#include <linux/skbuff.h>
 151
 152struct net;
 153
 154static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
 155{
 156        return (struct nlmsghdr *)skb->data;
 157}
 158
 159struct netlink_skb_parms {
 160        struct ucred            creds;          /* Skb credentials      */
 161        __u32                   pid;
 162        __u32                   dst_group;
 163        kernel_cap_t            eff_cap;
 164        __u32                   loginuid;       /* Login (audit) uid */
 165        __u32                   sessionid;      /* Session id (audit) */
 166        __u32                   sid;            /* SELinux security id */
 167};
 168
 169#define NETLINK_CB(skb)         (*(struct netlink_skb_parms*)&((skb)->cb))
 170#define NETLINK_CREDS(skb)      (&NETLINK_CB((skb)).creds)
 171
 172
 173extern void netlink_table_grab(void);
 174extern void netlink_table_ungrab(void);
 175
 176extern struct sock *netlink_kernel_create(struct net *net,
 177                                          int unit,unsigned int groups,
 178                                          void (*input)(struct sk_buff *skb),
 179                                          struct mutex *cb_mutex,
 180                                          struct module *module);
 181extern void netlink_kernel_release(struct sock *sk);
 182extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
 183extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
 184extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
 185extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group);
 186extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
 187extern int netlink_has_listeners(struct sock *sk, unsigned int group);
 188extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 pid, int nonblock);
 189extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,
 190                             __u32 group, gfp_t allocation);
 191extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
 192        __u32 pid, __u32 group, gfp_t allocation,
 193        int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
 194        void *filter_data);
 195extern int netlink_set_err(struct sock *ssk, __u32 pid, __u32 group, int code);
 196extern int netlink_register_notifier(struct notifier_block *nb);
 197extern int netlink_unregister_notifier(struct notifier_block *nb);
 198
 199/* finegrained unicast helpers: */
 200struct sock *netlink_getsockbyfilp(struct file *filp);
 201int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
 202                      long *timeo, struct sock *ssk);
 203void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
 204int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
 205
 206/*
 207 *      skb should fit one page. This choice is good for headerless malloc.
 208 *      But we should limit to 8K so that userspace does not have to
 209 *      use enormous buffer sizes on recvmsg() calls just to avoid
 210 *      MSG_TRUNC when PAGE_SIZE is very large.
 211 */
 212#if PAGE_SIZE < 8192UL
 213#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(PAGE_SIZE)
 214#else
 215#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(8192UL)
 216#endif
 217
 218#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
 219
 220
 221struct netlink_callback {
 222        struct sk_buff          *skb;
 223        const struct nlmsghdr   *nlh;
 224        int                     (*dump)(struct sk_buff * skb,
 225                                        struct netlink_callback *cb);
 226        int                     (*done)(struct netlink_callback *cb);
 227        int                     family;
 228        long                    args[6];
 229};
 230
 231struct netlink_notify {
 232        struct net *net;
 233        int pid;
 234        int protocol;
 235};
 236
 237static __inline__ struct nlmsghdr *
 238__nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
 239{
 240        struct nlmsghdr *nlh;
 241        int size = NLMSG_LENGTH(len);
 242
 243        nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
 244        nlh->nlmsg_type = type;
 245        nlh->nlmsg_len = size;
 246        nlh->nlmsg_flags = flags;
 247        nlh->nlmsg_pid = pid;
 248        nlh->nlmsg_seq = seq;
 249        if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
 250                memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size);
 251        return nlh;
 252}
 253
 254#define NLMSG_NEW(skb, pid, seq, type, len, flags) \
 255({      if (unlikely(skb_tailroom(skb) < (int)NLMSG_SPACE(len))) \
 256                goto nlmsg_failure; \
 257        __nlmsg_put(skb, pid, seq, type, len, flags); })
 258
 259#define NLMSG_PUT(skb, pid, seq, type, len) \
 260        NLMSG_NEW(skb, pid, seq, type, len, 0)
 261
 262extern int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 263                              const struct nlmsghdr *nlh,
 264                              int (*dump)(struct sk_buff *skb, struct netlink_callback*),
 265                              int (*done)(struct netlink_callback*));
 266
 267
 268#define NL_NONROOT_RECV 0x1
 269#define NL_NONROOT_SEND 0x2
 270extern void netlink_set_nonroot(int protocol, unsigned flag);
 271
 272#endif /* __KERNEL__ */
 273
 274#endif  /* __LINUX_NETLINK_H */
 275