kernel/fs/sockfs/socktpi.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  24  */
  25
  26 #ifndef _SOCKFS_SOCKTPI_H
  27 #define _SOCKFS_SOCKTPI_H
  28
  29 #ifdef  __cplusplus
  30 extern "C" {
  31 #endif
  32
  33 /*
  34  * Internal representation used for addresses.
  35  */
  36 struct soaddr {
  37         struct sockaddr *soa_sa;        /* Actual address */
  38         t_uscalar_t     soa_len;        /* Length in bytes for kmem_free */
  39         t_uscalar_t     soa_maxlen;     /* Allocated length */
  40 };
  41 /* Maximum size address for transports that have ADDR_size == 1 */
  42 #define SOA_DEFSIZE     128
  43
  44 struct sonode;
  45
  46 /*
  47  * TPI Sockets
  48  * ======================
  49  *
  50  * A TPI socket can be created by the TPI socket module, or as a
  51  * result of fallback. In either case, the TPI related information is
  52  * stored in a sotpi_info_t. Sockets that are TPI based from the
  53  * beginning will use a sotpi_sonode_t, but fallback case the
  54  * sotpi_info_t will be allocated when needed. However, the so_priv
  55  * field in the sonode will always point to the sotpi_info_t, and the
  56  * structure should only be accessed via so_priv. Use SOTOTPI().
  57  *
  58  * A TPI socket always corresponds to a VCHR stream representing the
  59  * transport provider (e.g. /dev/tcp). This information is retrieved
  60  * from the kernel socket configuration table and accessible via
  61  * so_sockparams->sp_sdev_info.  sockfs uses this to perform
  62  * fop_access checks before allowing an open of the transport
  63  * provider.
  64  *
  65  * AF_UNIX Sockets
  66  * -------------------------
  67  *
  68  * When an AF_UNIX socket is bound to a pathname the sockfs creates a
  69  * VSOCK vnode in the underlying file system. However, the vnodeops
  70  * etc in this VNODE remain those of the underlying file system.
  71  * Sockfs uses the v_stream pointer in the underlying file system
  72  * VSOCK node to find the sonode bound to the pathname. The bound
  73  * pathname vnode is accessed through sti_ux_vp.
  74  *
  75  * Out of Band Data Handling
  76  * -------------------------
  77  *
  78  * The counts (sti_oobcnt and sti_oobsigcnt) track the number of
  79  * urgent indicates that are (logically) queued on the stream head
  80  * read queue. The urgent data is queued on the stream head
  81  * as follows.
  82  *
  83  * In the normal case the SIGURG is not generated until
  84  * the T_EXDATA_IND arrives at the stream head. However, transports
  85  * that have an early indication that urgent data is pending
  86  * (e.g. TCP receiving a "new" urgent pointer value) can send up
  87  * an M_PCPROTO/SIGURG message to generate the signal early.
  88  *
  89  * The mark is indicated by either:
  90  *  - a T_EXDATA_IND (with no M_DATA b_cont) with MSGMARK set.
  91  *    When this message is consumed by sorecvmsg the socket layer
  92  *    sets SS_RCVATMARK until data has been consumed past the mark.
  93  *  - a message with MSGMARKNEXT set (indicating that the
  94  *    first byte of the next message constitutes the mark). When
  95  *    the last byte of the MSGMARKNEXT message is consumed in
  96  *    the stream head the stream head sets STRATMARK. This flag
  97  *    is cleared when at least one byte is read. (Note that
  98  *    the MSGMARKNEXT messages can be of zero length when there
  99  *    is no previous data to which the marknext can be attached.)
 100  *
 101  * While the T_EXDATA_IND method is the common case which is used
 102  * with all TPI transports, the MSGMARKNEXT method is needed to
 103  * indicate the mark when e.g. the TCP urgent byte has not been
 104  * received yet but the TCP urgent pointer has made TCP generate
 105  * the M_PCSIG/SIGURG.
 106  *
 107  * The signal (the M_PCSIG carrying the SIGURG) and the mark
 108  * indication can not be delivered as a single message, since
 109  * the signal should be delivered as high priority and any mark
 110  * indication must flow with the data. This implies that immediately
 111  * when the SIGURG has been delivered if the stream head queue is
 112  * empty it is impossible to determine if this will be the position
 113  * of the mark. This race condition is resolved by using MSGNOTMARKNEXT
 114  * messages and the STRNOTATMARK flag in the stream head. The
 115  * SIOCATMARK code calls the stream head to wait for either a
 116  * non-empty queue or one of the STR*ATMARK flags being set.
 117  * This implies that any transport that is sending M_PCSIG(SIGURG)
 118  * should send the appropriate MSGNOTMARKNEXT message (which can be
 119  * zero length) after sending an M_PCSIG to prevent SIOCATMARK
 120  * from sleeping unnecessarily.
 121  */
 122
 123 #define SOTPI_INFO_MAGIC        0x12345678
 124
 125 /*
 126  * Information used by TPI/STREAMS sockets
 127  */
 128 typedef struct sotpi_info {
 129         /*
 130          * These fields are initialized once.
 131          */
 132         uint32_t        sti_magic;      /* always set to SOTPI_INFO_MAGIC */
 133         dev_t           sti_dev;        /* device the sonode represents */
 134
 135         struct sockparams *sti_orig_sp; /* in case of fallback; the orig sp */
 136
 137         kmutex_t        sti_plumb_lock; /* serializes plumbs, and the related */
 138                                         /* so_pushcnt */
 139         short           sti_pushcnt;    /* Number of modules above "sockmod" */
 140
 141         kcondvar_t      sti_ack_cv;     /* wait for TPI acks */
 142
 143         uint8_t
 144                 sti_laddr_valid : 1,    /* sti_laddr valid for user */
 145                 sti_faddr_valid : 1,    /* sti_faddr valid for user */
 146                 sti_faddr_noxlate : 1,  /* No xlation of faddr for AF_UNIX */
 147
 148                 sti_direct : 1,         /* transport is directly below */
 149
 150                 sti_pad_to_bit7 : 4;
 151
 152         mblk_t  *sti_ack_mp;            /* TPI ack received from below */
 153         mblk_t  *sti_unbind_mp;         /* Preallocated T_UNBIND_REQ message */
 154
 155         time_t  sti_atime;              /* time of last access */
 156         time_t  sti_mtime;              /* time of last modification */
 157         time_t  sti_ctime;              /* time of last attributes change */
 158
 159         ushort_t sti_delayed_error;     /* From T_uderror_ind */
 160         mblk_t  *sti_eaddr_mp;          /* for so_delayed_error */
 161                                         /* put here for delayed processing  */
 162
 163         mblk_t  *sti_conn_ind_head;     /* b_next list of T_CONN_IND */
 164         mblk_t  *sti_conn_ind_tail;
 165
 166         uint_t  sti_oobsigcnt;          /* Number of SIGURG generated */
 167         uint_t  sti_oobcnt;             /* Number of T_EXDATA_IND queued */
 168
 169         /* From T_info_ack */
 170         t_uscalar_t     sti_tsdu_size;
 171         t_uscalar_t     sti_etsdu_size;
 172         t_scalar_t      sti_addr_size;
 173         t_uscalar_t     sti_opt_size;
 174         t_uscalar_t     sti_tidu_size;
 175         t_scalar_t      sti_serv_type;
 176
 177         /* From T_capability_ack */
 178         t_uscalar_t     sti_acceptor_id;
 179
 180         /* Internal provider information */
 181         struct tpi_provinfo     *sti_provinfo;
 182
 183         /*
 184          * The local and remote addresses have multiple purposes
 185          * but one of the key reasons for their existence and careful
 186          * tracking in sockfs is to support getsockname and getpeername
 187          * when the transport does not handle the TI_GET*NAME ioctls
 188          * and caching when it does (signalled by valid bits in so_state).
 189          * When all transports support the new TPI (with T_ADDR_REQ)
 190          * we can revisit this code.
 191          *
 192          * The other usage of sti_faddr is to keep the "connected to"
 193          * address for datagram sockets.
 194          *
 195          * Finally, for AF_UNIX both local and remote addresses are used
 196          * to record the sockaddr_un since we use a separate namespace
 197          * in the loopback transport.
 198          */
 199         struct soaddr sti_laddr;        /* Local address */
 200         struct soaddr sti_faddr;        /* Peer address */
 201 #define sti_laddr_sa            sti_laddr.soa_sa
 202 #define sti_faddr_sa            sti_faddr.soa_sa
 203 #define sti_laddr_len           sti_laddr.soa_len
 204 #define sti_faddr_len           sti_faddr.soa_len
 205 #define sti_laddr_maxlen        sti_laddr.soa_maxlen
 206 #define sti_faddr_maxlen        sti_faddr.soa_maxlen
 207
 208         /*
 209          * For AF_UNIX sockets:
 210          *
 211          * sti_ux_laddr/faddr records the internal addresses used with the
 212          * transport. sti_ux_vp and v_stream->sd_vnode form the
 213          * cross-linkage between the underlying fs vnode corresponding
 214          * to the bound sockaddr_un and the socket node.
 215          *
 216          * sti_ux_taddr holds the result of translations done in
 217          * so_ux_addr_xlate(), which may or may not be the same as
 218          * sti_ux_faddr (which is our connected peer address).
 219          */
 220         struct so_ux_addr sti_ux_laddr; /* laddr bound with the transport */
 221         struct so_ux_addr sti_ux_faddr; /* connected peer address */
 222         struct so_ux_addr sti_ux_taddr; /* temporary address for sendmsg */
 223         struct vnode    *sti_ux_bound_vp; /* bound AF_UNIX file system vnode */
 224         struct sonode   *sti_next_so;   /* next sonode on socklist      */
 225         struct sonode   *sti_prev_so;   /* previous sonode on socklist  */
 226         mblk_t  *sti_discon_ind_mp;     /* T_DISCON_IND received from below */
 227 } sotpi_info_t;
 228
 229 struct T_capability_ack;
 230
 231 extern sonodeops_t sotpi_sonodeops;
 232
 233 extern int      socktpi_init(void);
 234 extern int      sotpi_convert_sonode(struct sonode *, struct sockparams *,
 235                     boolean_t *, queue_t **, struct cred *);
 236 extern void     sotpi_revert_sonode(struct sonode *, struct cred *);
 237 extern void     sotpi_update_state(struct sonode *, struct T_capability_ack *,
 238                     struct sockaddr *, socklen_t, struct sockaddr *, socklen_t,
 239                     short);
 240
 241 extern sotpi_info_t     *sotpi_sototpi(struct sonode *);
 242 #ifdef DEBUG
 243 #define SOTOTPI(so)     (sotpi_sototpi(so))
 244 #else
 245 #define SOTOTPI(so)     ((sotpi_info_t *)(so)->so_priv)
 246 #endif
 247
 248 /* for consumers outside sockfs */
 249 #define _SOTOTPI(so)    ((sotpi_info_t *)(so)->so_priv)
 250
 251 #ifdef  __cplusplus
 252 }
 253 #endif
 254
 255 #endif /* _SOCKFS_SOCKTPI_H */