LXR linux/include/linux/netlink.h

   1#ifndef __LINUX_NETLINK_H
   2#define __LINUX_NETLINK_H
   3
   4#include <linux/socket.h> /* for __kernel_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#define NETLINK_RDMA            20
  28#define NETLINK_CRYPTO          21      /* Crypto layer */
  29
  30#define MAX_LINKS 32            
  31
  32struct sockaddr_nl {
  33        __kernel_sa_family_t    nl_family;      /* AF_NETLINK   */
  34        unsigned short  nl_pad;         /* zero         */
  35        __u32           nl_pid;         /* port ID      */
  36        __u32           nl_groups;      /* multicast groups mask */
  37};
  38
  39struct nlmsghdr {
  40        __u32           nlmsg_len;      /* Length of message including header */
  41        __u16           nlmsg_type;     /* Message content */
  42        __u16           nlmsg_flags;    /* Additional flags */
  43        __u32           nlmsg_seq;      /* Sequence number */
  44        __u32           nlmsg_pid;      /* Sending process port ID */
  45};
  46
  47/* Flags values */
  48
  49#define NLM_F_REQUEST           1       /* It is request message.       */
  50#define NLM_F_MULTI             2       /* Multipart message, terminated by NLMSG_DONE */
  51#define NLM_F_ACK               4       /* Reply with ack, with zero or error code */
  52#define NLM_F_ECHO              8       /* Echo this request            */
  53#define NLM_F_DUMP_INTR         16      /* Dump was inconsistent due to sequence change */
  54
  55/* Modifiers to GET request */
  56#define NLM_F_ROOT      0x100   /* specify tree root    */
  57#define NLM_F_MATCH     0x200   /* return all matching  */
  58#define NLM_F_ATOMIC    0x400   /* atomic GET           */
  59#define NLM_F_DUMP      (NLM_F_ROOT|NLM_F_MATCH)
  60
  61/* Modifiers to NEW request */
  62#define NLM_F_REPLACE   0x100   /* Override existing            */
  63#define NLM_F_EXCL      0x200   /* Do not touch, if it exists   */
  64#define NLM_F_CREATE    0x400   /* Create, if it does not exist */
  65#define NLM_F_APPEND    0x800   /* Add to end of list           */
  66
  67/*
  68   4.4BSD ADD           NLM_F_CREATE|NLM_F_EXCL
  69   4.4BSD CHANGE        NLM_F_REPLACE
  70
  71   True CHANGE          NLM_F_CREATE|NLM_F_REPLACE
  72   Append               NLM_F_CREATE
  73   Check                NLM_F_EXCL
  74 */
  75
  76#define NLMSG_ALIGNTO   4U
  77#define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )
  78#define NLMSG_HDRLEN     ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
  79#define NLMSG_LENGTH(len) ((len)+NLMSG_ALIGN(NLMSG_HDRLEN))
  80#define NLMSG_SPACE(len) NLMSG_ALIGN(NLMSG_LENGTH(len))
  81#define NLMSG_DATA(nlh)  ((void*)(((char*)nlh) + NLMSG_LENGTH(0)))
  82#define NLMSG_NEXT(nlh,len)      ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
  83                                  (struct nlmsghdr*)(((char*)(nlh)) + NLMSG_ALIGN((nlh)->nlmsg_len)))
  84#define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
  85                           (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
  86                           (nlh)->nlmsg_len <= (len))
  87#define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))
  88
  89#define NLMSG_NOOP              0x1     /* Nothing.             */
  90#define NLMSG_ERROR             0x2     /* Error                */
  91#define NLMSG_DONE              0x3     /* End of a dump        */
  92#define NLMSG_OVERRUN           0x4     /* Data lost            */
  93
  94#define NLMSG_MIN_TYPE          0x10    /* < 0x10: reserved control messages */
  95
  96struct nlmsgerr {
  97        int             error;
  98        struct nlmsghdr msg;
  99};
 100
 101#define NETLINK_ADD_MEMBERSHIP  1
 102#define NETLINK_DROP_MEMBERSHIP 2
 103#define NETLINK_PKTINFO         3
 104#define NETLINK_BROADCAST_ERROR 4
 105#define NETLINK_NO_ENOBUFS      5
 106
 107struct nl_pktinfo {
 108        __u32   group;
 109};
 110
 111#define NET_MAJOR 36            /* Major 36 is reserved for networking                                          */
 112
 113enum {
 114        NETLINK_UNCONNECTED = 0,
 115        NETLINK_CONNECTED,
 116};
 117
 118/*
 119 *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
 120 * +---------------------+- - -+- - - - - - - - - -+- - -+
 121 * |        Header       | Pad |     Payload       | Pad |
 122 * |   (struct nlattr)   | ing |                   | ing |
 123 * +---------------------+- - -+- - - - - - - - - -+- - -+
 124 *  <-------------- nlattr->nla_len -------------->
 125 */
 126
 127struct nlattr {
 128        __u16           nla_len;
 129        __u16           nla_type;
 130};
 131
 132/*
 133 * nla_type (16 bits)
 134 * +---+---+-------------------------------+
 135 * | N | O | Attribute Type                |
 136 * +---+---+-------------------------------+
 137 * N := Carries nested attributes
 138 * O := Payload stored in network byte order
 139 *
 140 * Note: The N and O flag are mutually exclusive.
 141 */
 142#define NLA_F_NESTED            (1 << 15)
 143#define NLA_F_NET_BYTEORDER     (1 << 14)
 144#define NLA_TYPE_MASK           ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
 145
 146#define NLA_ALIGNTO             4
 147#define NLA_ALIGN(len)          (((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
 148#define NLA_HDRLEN              ((int) NLA_ALIGN(sizeof(struct nlattr)))
 149
 150#ifdef __KERNEL__
 151
 152#include <linux/capability.h>
 153#include <linux/skbuff.h>
 154
 155struct net;
 156
 157static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
 158{
 159        return (struct nlmsghdr *)skb->data;
 160}
 161
 162struct netlink_skb_parms {
 163        struct ucred            creds;          /* Skb credentials      */
 164        __u32                   pid;
 165        __u32                   dst_group;
 166};
 167
 168#define NETLINK_CB(skb)         (*(struct netlink_skb_parms*)&((skb)->cb))
 169#define NETLINK_CREDS(skb)      (&NETLINK_CB((skb)).creds)
 170
 171
 172extern void netlink_table_grab(void);
 173extern void netlink_table_ungrab(void);
 174
 175extern struct sock *netlink_kernel_create(struct net *net,
 176                                          int unit,unsigned int groups,
 177                                          void (*input)(struct sk_buff *skb),
 178                                          struct mutex *cb_mutex,
 179                                          struct module *module);
 180extern void netlink_kernel_release(struct sock *sk);
 181extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
 182extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
 183extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
 184extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group);
 185extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
 186extern int netlink_has_listeners(struct sock *sk, unsigned int group);
 187extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 pid, int nonblock);
 188extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,
 189                             __u32 group, gfp_t allocation);
 190extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
 191        __u32 pid, __u32 group, gfp_t allocation,
 192        int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
 193        void *filter_data);
 194extern int netlink_set_err(struct sock *ssk, __u32 pid, __u32 group, int code);
 195extern int netlink_register_notifier(struct notifier_block *nb);
 196extern int netlink_unregister_notifier(struct notifier_block *nb);
 197
 198/* finegrained unicast helpers: */
 199struct sock *netlink_getsockbyfilp(struct file *filp);
 200int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
 201                      long *timeo, struct sock *ssk);
 202void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
 203int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
 204
 205/*
 206 *      skb should fit one page. This choice is good for headerless malloc.
 207 *      But we should limit to 8K so that userspace does not have to
 208 *      use enormous buffer sizes on recvmsg() calls just to avoid
 209 *      MSG_TRUNC when PAGE_SIZE is very large.
 210 */
 211#if PAGE_SIZE < 8192UL
 212#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(PAGE_SIZE)
 213#else
 214#define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(8192UL)
 215#endif
 216
 217#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
 218
 219
 220struct netlink_callback {
 221        struct sk_buff          *skb;
 222        const struct nlmsghdr   *nlh;
 223        int                     (*dump)(struct sk_buff * skb,
 224                                        struct netlink_callback *cb);
 225        int                     (*done)(struct netlink_callback *cb);
 226        u16                     family;
 227        u16                     min_dump_alloc;
 228        unsigned int            prev_seq, seq;
 229        long                    args[6];
 230};
 231
 232struct netlink_notify {
 233        struct net *net;
 234        int pid;
 235        int protocol;
 236};
 237
 238static __inline__ struct nlmsghdr *
 239__nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
 240{
 241        struct nlmsghdr *nlh;
 242        int size = NLMSG_LENGTH(len);
 243
 244        nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
 245        nlh->nlmsg_type = type;
 246        nlh->nlmsg_len = size;
 247        nlh->nlmsg_flags = flags;
 248        nlh->nlmsg_pid = pid;
 249        nlh->nlmsg_seq = seq;
 250        if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
 251                memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size);
 252        return nlh;
 253}
 254
 255#define NLMSG_NEW(skb, pid, seq, type, len, flags) \
 256({      if (unlikely(skb_tailroom(skb) < (int)NLMSG_SPACE(len))) \
 257                goto nlmsg_failure; \
 258        __nlmsg_put(skb, pid, seq, type, len, flags); })
 259
 260#define NLMSG_PUT(skb, pid, seq, type, len) \
 261        NLMSG_NEW(skb, pid, seq, type, len, 0)
 262
 263extern int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 264                              const struct nlmsghdr *nlh,
 265                              int (*dump)(struct sk_buff *skb, struct netlink_callback*),
 266                              int (*done)(struct netlink_callback*),
 267                              u16 min_dump_alloc);
 268
 269
 270#define NL_NONROOT_RECV 0x1
 271#define NL_NONROOT_SEND 0x2
 272extern void netlink_set_nonroot(int protocol, unsigned flag);
 273
 274#endif /* __KERNEL__ */
 275
 276#endif  /* __LINUX_NETLINK_H */
 277