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 sockaddr_nl
  31 {
  32         sa_family_t     nl_family;      /* AF_NETLINK   */
  33         unsigned short  nl_pad;         /* zero         */
  34         __u32           nl_pid;         /* port ID      */
  35         __u32           nl_groups;      /* multicast groups mask */
  36 };
  37
  38 struct nlmsghdr
  39 {
  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 {
  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
 105 struct nl_pktinfo
 106 {
 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 {
 128         __u16           nla_len;
 129         __u16           nla_type;
 130 };
 131
 132 #define NLA_ALIGNTO             4
 133 #define NLA_ALIGN(len)          (((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
 134 #define NLA_HDRLEN              ((int) NLA_ALIGN(sizeof(struct nlattr)))
 135
 136 #ifdef __KERNEL__
 137
 138 #include <linux/capability.h>
 139 #include <linux/skbuff.h>
 140
 141 static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
 142 {
 143         return (struct nlmsghdr *)skb->data;
 144 }
 145
 146 struct netlink_skb_parms
 147 {
 148         struct ucred            creds;          /* Skb credentials      */
 149         __u32                   pid;
 150         __u32                   dst_group;
 151         kernel_cap_t            eff_cap;
 152         __u32                   loginuid;       /* Login (audit) uid */
 153         __u32                   sid;            /* SELinux security id */
 154 };
 155
 156 #define NETLINK_CB(skb)         (*(struct netlink_skb_parms*)&((skb)->cb))
 157 #define NETLINK_CREDS(skb)      (&NETLINK_CB((skb)).creds)
 158
 159
 160 extern struct sock *netlink_kernel_create(int unit, unsigned int groups,
 161                                           void (*input)(struct sock *sk, int len),
 162                                           struct mutex *cb_mutex,
 163                                           struct module *module);
 164 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
 165 extern int netlink_has_listeners(struct sock *sk, unsigned int group);
 166 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 pid, int nonblock);
 167 extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,
 168                              __u32 group, gfp_t allocation);
 169 extern void netlink_set_err(struct sock *ssk, __u32 pid, __u32 group, int code);
 170 extern int netlink_register_notifier(struct notifier_block *nb);
 171 extern int netlink_unregister_notifier(struct notifier_block *nb);
 172
 173 /* finegrained unicast helpers: */
 174 struct sock *netlink_getsockbyfilp(struct file *filp);
 175 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock,
 176                       long *timeo, struct sock *ssk);
 177 void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
 178 int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol);
 179
 180 /*
 181  *      skb should fit one page. This choice is good for headerless malloc.
 182  *      But we should limit to 8K so that userspace does not have to
 183  *      use enormous buffer sizes on recvmsg() calls just to avoid
 184  *      MSG_TRUNC when PAGE_SIZE is very large.
 185  */
 186 #if PAGE_SIZE < 8192UL
 187 #define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(PAGE_SIZE)
 188 #else
 189 #define NLMSG_GOODSIZE  SKB_WITH_OVERHEAD(8192UL)
 190 #endif
 191
 192 #define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
 193
 194
 195 struct netlink_callback
 196 {
 197         struct sk_buff  *skb;
 198         struct nlmsghdr *nlh;
 199         int             (*dump)(struct sk_buff * skb, struct netlink_callback *cb);
 200         int             (*done)(struct netlink_callback *cb);
 201         int             family;
 202         long            args[5];
 203 };
 204
 205 struct netlink_notify
 206 {
 207         int pid;
 208         int protocol;
 209 };
 210
 211 static __inline__ struct nlmsghdr *
 212 __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
 213 {
 214         struct nlmsghdr *nlh;
 215         int size = NLMSG_LENGTH(len);
 216
 217         nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
 218         nlh->nlmsg_type = type;
 219         nlh->nlmsg_len = size;
 220         nlh->nlmsg_flags = flags;
 221         nlh->nlmsg_pid = pid;
 222         nlh->nlmsg_seq = seq;
 223         memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size);
 224         return nlh;
 225 }
 226
 227 #define NLMSG_NEW(skb, pid, seq, type, len, flags) \
 228 ({      if (skb_tailroom(skb) < (int)NLMSG_SPACE(len)) \
 229                 goto nlmsg_failure; \
 230         __nlmsg_put(skb, pid, seq, type, len, flags); })
 231
 232 #define NLMSG_PUT(skb, pid, seq, type, len) \
 233         NLMSG_NEW(skb, pid, seq, type, len, 0)
 234
 235 extern int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 236                               struct nlmsghdr *nlh,
 237                               int (*dump)(struct sk_buff *skb, struct netlink_callback*),
 238                               int (*done)(struct netlink_callback*));
 239
 240
 241 #define NL_NONROOT_RECV 0x1
 242 #define NL_NONROOT_SEND 0x2
 243 extern void netlink_set_nonroot(int protocol, unsigned flag);
 244
 245 #endif /* __KERNEL__ */
 246
 247 #endif  /* __LINUX_NETLINK_H */