net/netlabel/netlabel_user.h

   1 /*
   2  * NetLabel NETLINK Interface
   3  *
   4  * This file defines the NETLINK interface for the NetLabel system.  The
   5  * NetLabel system manages static and dynamic label mappings for network
   6  * protocols such as CIPSO and RIPSO.
   7  *
   8  * Author: Paul Moore <paul.moore@hp.com>
   9  *
  10  */
  11
  12 /*
  13  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
  14  *
  15  * This program is free software;  you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or
  18  * (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  23  * the GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program;  if not, write to the Free Software
  27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  28  *
  29  */
  30
  31 #ifndef _NETLABEL_USER_H
  32 #define _NETLABEL_USER_H
  33
  34 #include <linux/skbuff.h>
  35 #include <linux/capability.h>
  36 #include <linux/genetlink.h>
  37 #include <net/netlabel.h>
  38 #include <net/genetlink.h>
  39
  40 /* NetLabel NETLINK helper functions */
  41
  42 /**
  43  * netlbl_netlink_cap_check - Check the NETLINK msg capabilities
  44  * @skb: the NETLINK buffer
  45  * @req_cap: the required capability
  46  *
  47  * Description:
  48  * Check the NETLINK buffer's capabilities against the required capabilities.
  49  * Returns zero on success, negative values on failure.
  50  *
  51  */
  52 static inline int netlbl_netlink_cap_check(const struct sk_buff *skb,
  53                                            kernel_cap_t req_cap)
  54 {
  55         if (cap_raised(NETLINK_CB(skb).eff_cap, req_cap))
  56                 return 0;
  57         return -EPERM;
  58 }
  59
  60 /**
  61  * netlbl_getinc_u8 - Read a u8 value from a nlattr stream and move on
  62  * @nla: the attribute
  63  * @rem_len: remaining length
  64  *
  65  * Description:
  66  * Return a u8 value pointed to by @nla and advance it to the next attribute.
  67  *
  68  */
  69 static inline u8 netlbl_getinc_u8(struct nlattr **nla, int *rem_len)
  70 {
  71         u8 val = nla_get_u8(*nla);
  72         *nla = nla_next(*nla, rem_len);
  73         return val;
  74 }
  75
  76 /**
  77  * netlbl_getinc_u16 - Read a u16 value from a nlattr stream and move on
  78  * @nla: the attribute
  79  * @rem_len: remaining length
  80  *
  81  * Description:
  82  * Return a u16 value pointed to by @nla and advance it to the next attribute.
  83  *
  84  */
  85 static inline u16 netlbl_getinc_u16(struct nlattr **nla, int *rem_len)
  86 {
  87         u16 val = nla_get_u16(*nla);
  88         *nla = nla_next(*nla, rem_len);
  89         return val;
  90 }
  91
  92 /**
  93  * netlbl_getinc_u32 - Read a u32 value from a nlattr stream and move on
  94  * @nla: the attribute
  95  * @rem_len: remaining length
  96  *
  97  * Description:
  98  * Return a u32 value pointed to by @nla and advance it to the next attribute.
  99  *
 100  */
 101 static inline u32 netlbl_getinc_u32(struct nlattr **nla, int *rem_len)
 102 {
 103         u32 val = nla_get_u32(*nla);
 104         *nla = nla_next(*nla, rem_len);
 105         return val;
 106 }
 107
 108 /**
 109  * netlbl_netlink_hdr_put - Write the NETLINK buffers into a sk_buff
 110  * @skb: the packet
 111  * @pid: the PID of the receipient
 112  * @seq: the sequence number
 113  * @type: the generic NETLINK message family type
 114  * @cmd: command
 115  *
 116  * Description:
 117  * Write both a NETLINK nlmsghdr structure and a Generic NETLINK genlmsghdr
 118  * struct to the packet.  Returns a pointer to the start of the payload buffer
 119  * on success or NULL on failure.
 120  *
 121  */
 122 static inline void *netlbl_netlink_hdr_put(struct sk_buff *skb,
 123                                            u32 pid,
 124                                            u32 seq,
 125                                            int type,
 126                                            u8 cmd)
 127 {
 128         return genlmsg_put(skb,
 129                            pid,
 130                            seq,
 131                            type,
 132                            0,
 133                            0,
 134                            cmd,
 135                            NETLBL_PROTO_VERSION);
 136 }
 137
 138 /**
 139  * netlbl_netlink_hdr_push - Write the NETLINK buffers into a sk_buff
 140  * @skb: the packet
 141  * @pid: the PID of the receipient
 142  * @seq: the sequence number
 143  * @type: the generic NETLINK message family type
 144  * @cmd: command
 145  *
 146  * Description:
 147  * Write both a NETLINK nlmsghdr structure and a Generic NETLINK genlmsghdr
 148  * struct to the packet.
 149  *
 150  */
 151 static inline void netlbl_netlink_hdr_push(struct sk_buff *skb,
 152                                            u32 pid,
 153                                            u32 seq,
 154                                            int type,
 155                                            u8 cmd)
 156
 157 {
 158         struct nlmsghdr *nlh;
 159         struct genlmsghdr *hdr;
 160
 161         nlh = (struct nlmsghdr *)skb_push(skb, NLMSG_SPACE(GENL_HDRLEN));
 162         nlh->nlmsg_type = type;
 163         nlh->nlmsg_len = skb->len;
 164         nlh->nlmsg_flags = 0;
 165         nlh->nlmsg_pid = pid;
 166         nlh->nlmsg_seq = seq;
 167
 168         hdr = nlmsg_data(nlh);
 169         hdr->cmd = cmd;
 170         hdr->version = NETLBL_PROTO_VERSION;
 171         hdr->reserved = 0;
 172 }
 173
 174 /**
 175  * netlbl_netlink_payload_len - Return the length of the payload
 176  * @skb: the NETLINK buffer
 177  *
 178  * Description:
 179  * This function returns the length of the NetLabel payload.
 180  *
 181  */
 182 static inline u32 netlbl_netlink_payload_len(const struct sk_buff *skb)
 183 {
 184         return nlmsg_len((struct nlmsghdr *)skb->data) - GENL_HDRLEN;
 185 }
 186
 187 /**
 188  * netlbl_netlink_payload_data - Returns a pointer to the start of the payload
 189  * @skb: the NETLINK buffer
 190  *
 191  * Description:
 192  * This function returns a pointer to the start of the NetLabel payload.
 193  *
 194  */
 195 static inline void *netlbl_netlink_payload_data(const struct sk_buff *skb)
 196 {
 197   return (unsigned char *)nlmsg_data((struct nlmsghdr *)skb->data) +
 198           GENL_HDRLEN;
 199 }
 200
 201 /* NetLabel common protocol functions */
 202
 203 void netlbl_netlink_send_ack(const struct genl_info *info,
 204                              u32 genl_family,
 205                              u8 ack_cmd,
 206                              u32 ret_code);
 207
 208 /* NetLabel NETLINK I/O functions */
 209
 210 int netlbl_netlink_init(void);
 211 int netlbl_netlink_snd(struct sk_buff *skb, u32 pid);
 212 int netlbl_netlink_snd_multicast(struct sk_buff *skb, u32 pid, u32 group);
 213
 214 #endif