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
  32 struct 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
  39 struct 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
  96 struct 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
 107 struct nl_pktinfo {
 108         __u32   group;
 109 };
 110
 111 #define NET_MAJOR 36            /* Major 36 is reserved for networking                                          */
 112
 113 enum {
 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
 127 struct 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
 155 struct net;
 156
 157 static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
 158 {
 159         return (struct nlmsghdr *)skb->data;
 160 }
 161
 162 struct 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
 172 extern void netlink_table_grab(void);
 173 extern void netlink_table_ungrab(void);
 174
 175 extern 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);
 180 extern void netlink_kernel_release(struct sock *sk);
 181 extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
 182 extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
 183 extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
 184 extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group);
 185 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
 186 extern int netlink_has_listeners(struct sock *sk, unsigned int group);
 187 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 pid, int nonblock);
 188 extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,
 189                              __u32 group, gfp_t allocation);
 190 extern 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);
 194 extern int netlink_set_err(struct sock *ssk, __u32 pid, __u32 group, int code);
 195 extern int netlink_register_notifier(struct notifier_block *nb);
 196 extern int netlink_unregister_notifier(struct notifier_block *nb);
 197
 198 /* finegrained unicast helpers: */
 199 struct sock *netlink_getsockbyfilp(struct file *filp);
 200 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
 201                       long *timeo, struct sock *ssk);
 202 void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
 203 int 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
 220 struct 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
 232 struct netlink_notify {
 233         struct net *net;
 234         int pid;
 235         int protocol;
 236 };
 237
 238 static __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
 263 extern 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
 272 extern void netlink_set_nonroot(int protocol, unsigned flag);
 273
 274 #endif /* __KERNEL__ */
 275
 276 #endif  /* __LINUX_NETLINK_H */