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