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
  25 #define MAX_LINKS 32
  26
  27 struct sockaddr_nl
  28 {
  29         sa_family_t     nl_family;      /* AF_NETLINK   */
  30         unsigned short  nl_pad;         /* zero         */
  31         __u32           nl_pid;         /* process pid  */
  32         __u32           nl_groups;      /* multicast groups mask */
  33 };
  34
  35 struct nlmsghdr
  36 {
  37         __u32           nlmsg_len;      /* Length of message including header */
  38         __u16           nlmsg_type;     /* Message content */
  39         __u16           nlmsg_flags;    /* Additional flags */
  40         __u32           nlmsg_seq;      /* Sequence number */
  41         __u32           nlmsg_pid;      /* Sending process PID */
  42 };
  43
  44 /* Flags values */
  45
  46 #define NLM_F_REQUEST           1       /* It is request message.       */
  47 #define NLM_F_MULTI             2       /* Multipart message, terminated by NLMSG_DONE */
  48 #define NLM_F_ACK               4       /* Reply with ack, with zero or error code */
  49 #define NLM_F_ECHO              8       /* Echo this request            */
  50
  51 /* Modifiers to GET request */
  52 #define NLM_F_ROOT      0x100   /* specify tree root    */
  53 #define NLM_F_MATCH     0x200   /* return all matching  */
  54 #define NLM_F_ATOMIC    0x400   /* atomic GET           */
  55 #define NLM_F_DUMP      (NLM_F_ROOT|NLM_F_MATCH)
  56
  57 /* Modifiers to NEW request */
  58 #define NLM_F_REPLACE   0x100   /* Override existing            */
  59 #define NLM_F_EXCL      0x200   /* Do not touch, if it exists   */
  60 #define NLM_F_CREATE    0x400   /* Create, if it does not exist */
  61 #define NLM_F_APPEND    0x800   /* Add to end of list           */
  62
  63 /*
  64    4.4BSD ADD           NLM_F_CREATE|NLM_F_EXCL
  65    4.4BSD CHANGE        NLM_F_REPLACE
  66
  67    True CHANGE          NLM_F_CREATE|NLM_F_REPLACE
  68    Append               NLM_F_CREATE
  69    Check                NLM_F_EXCL
  70  */
  71
  72 #define NLMSG_ALIGNTO   4
  73 #define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )
  74 #define NLMSG_HDRLEN     ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
  75 #define NLMSG_LENGTH(len) ((len)+NLMSG_ALIGN(NLMSG_HDRLEN))
  76 #define NLMSG_SPACE(len) NLMSG_ALIGN(NLMSG_LENGTH(len))
  77 #define NLMSG_DATA(nlh)  ((void*)(((char*)nlh) + NLMSG_LENGTH(0)))
  78 #define NLMSG_NEXT(nlh,len)      ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
  79                                   (struct nlmsghdr*)(((char*)(nlh)) + NLMSG_ALIGN((nlh)->nlmsg_len)))
  80 #define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
  81                            (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
  82                            (nlh)->nlmsg_len <= (len))
  83 #define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))
  84
  85 #define NLMSG_NOOP              0x1     /* Nothing.             */
  86 #define NLMSG_ERROR             0x2     /* Error                */
  87 #define NLMSG_DONE              0x3     /* End of a dump        */
  88 #define NLMSG_OVERRUN           0x4     /* Data lost            */
  89
  90 #define NLMSG_MIN_TYPE          0x10    /* < 0x10: reserved control messages */
  91
  92 struct nlmsgerr
  93 {
  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
 102 struct nl_pktinfo
 103 {
 104         __u32   group;
 105 };
 106
 107 #define NET_MAJOR 36            /* Major 36 is reserved for networking                                          */
 108
 109 enum {
 110         NETLINK_UNCONNECTED = 0,
 111         NETLINK_CONNECTED,
 112 };
 113
 114 /*
 115  *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
 116  * +---------------------+- - -+- - - - - - - - - -+- - -+
 117  * |        Header       | Pad |     Payload       | Pad |
 118  * |   (struct nlattr)   | ing |                   | ing |
 119  * +---------------------+- - -+- - - - - - - - - -+- - -+
 120  *  <-------------- nlattr->nla_len -------------->
 121  */
 122
 123 struct nlattr
 124 {
 125         __u16           nla_len;
 126         __u16           nla_type;
 127 };
 128
 129 #define NLA_ALIGNTO             4
 130 #define NLA_ALIGN(len)          (((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
 131 #define NLA_HDRLEN              ((int) NLA_ALIGN(sizeof(struct nlattr)))
 132
 133 #ifdef __KERNEL__
 134
 135 #include <linux/capability.h>
 136 #include <linux/skbuff.h>
 137
 138 struct netlink_skb_parms
 139 {
 140         struct ucred            creds;          /* Skb credentials      */
 141         __u32                   pid;
 142         __u32                   dst_pid;
 143         __u32                   dst_group;
 144         kernel_cap_t            eff_cap;
 145         __u32                   loginuid;       /* Login (audit) uid */
 146         __u32                   sid;            /* SELinux security id */
 147 };
 148
 149 #define NETLINK_CB(skb)         (*(struct netlink_skb_parms*)&((skb)->cb))
 150 #define NETLINK_CREDS(skb)      (&NETLINK_CB((skb)).creds)
 151
 152
 153 extern struct sock *netlink_kernel_create(int unit, unsigned int groups, void (*input)(struct sock *sk, int len), struct module *module);
 154 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
 155 extern int netlink_has_listeners(struct sock *sk, unsigned int group);
 156 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 pid, int nonblock);
 157 extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,
 158                              __u32 group, gfp_t allocation);
 159 extern void netlink_set_err(struct sock *ssk, __u32 pid, __u32 group, int code);
 160 extern int netlink_register_notifier(struct notifier_block *nb);
 161 extern int netlink_unregister_notifier(struct notifier_block *nb);
 162
 163 /* finegrained unicast helpers: */
 164 struct sock *netlink_getsockbyfilp(struct file *filp);
 165 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock,
 166                 long timeo, struct sock *ssk);
 167 void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
 168 int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol);
 169
 170 /*
 171  *      skb should fit one page. This choice is good for headerless malloc.
 172  */
 173 #define NLMSG_GOODORDER 0
 174 #define NLMSG_GOODSIZE (SKB_MAX_ORDER(0, NLMSG_GOODORDER))
 175
 176
 177 struct netlink_callback
 178 {
 179         struct sk_buff  *skb;
 180         struct nlmsghdr *nlh;
 181         int             (*dump)(struct sk_buff * skb, struct netlink_callback *cb);
 182         int             (*done)(struct netlink_callback *cb);
 183         int             family;
 184         long            args[5];
 185 };
 186
 187 struct netlink_notify
 188 {
 189         int pid;
 190         int protocol;
 191 };
 192
 193 static __inline__ struct nlmsghdr *
 194 __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
 195 {
 196         struct nlmsghdr *nlh;
 197         int size = NLMSG_LENGTH(len);
 198
 199         nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
 200         nlh->nlmsg_type = type;
 201         nlh->nlmsg_len = size;
 202         nlh->nlmsg_flags = flags;
 203         nlh->nlmsg_pid = pid;
 204         nlh->nlmsg_seq = seq;
 205         memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size);
 206         return nlh;
 207 }
 208
 209 #define NLMSG_NEW(skb, pid, seq, type, len, flags) \
 210 ({      if (skb_tailroom(skb) < (int)NLMSG_SPACE(len)) \
 211                 goto nlmsg_failure; \
 212         __nlmsg_put(skb, pid, seq, type, len, flags); })
 213
 214 #define NLMSG_PUT(skb, pid, seq, type, len) \
 215         NLMSG_NEW(skb, pid, seq, type, len, 0)
 216
 217 #define NLMSG_NEW_ANSWER(skb, cb, type, len, flags) \
 218         NLMSG_NEW(skb, NETLINK_CB((cb)->skb).pid, \
 219                   (cb)->nlh->nlmsg_seq, type, len, flags)
 220
 221 #define NLMSG_END(skb, nlh) \
 222 ({      (nlh)->nlmsg_len = (skb)->tail - (unsigned char *) (nlh); \
 223         (skb)->len; })
 224
 225 #define NLMSG_CANCEL(skb, nlh) \
 226 ({      skb_trim(skb, (unsigned char *) (nlh) - (skb)->data); \
 227         -1; })
 228
 229 extern int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 230                               struct nlmsghdr *nlh,
 231                               int (*dump)(struct sk_buff *skb, struct netlink_callback*),
 232                               int (*done)(struct netlink_callback*));
 233
 234
 235 #define NL_NONROOT_RECV 0x1
 236 #define NL_NONROOT_SEND 0x2
 237 extern void netlink_set_nonroot(int protocol, unsigned flag);
 238
 239 #endif /* __KERNEL__ */
 240
 241 #endif  /* __LINUX_NETLINK_H */