common/inet/ip_impl.h

	ip_impl.h revision 10e6dadfe63181edabc58c8f42e3c56a1cd9ec95
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef _INET_IP_IMPL_H
#define _INET_IP_IMPL_H

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * IP implementation private declarations.  These interfaces are
 * used to build the IP module and are not meant to be accessed
 * by any modules except IP itself.  They are undocumented and are
 * subject to change without notice.
 */

#ifdef  __cplusplus
extern "C" {
#endif

#ifdef _KERNEL

#include <sys/sdt.h>

#define IP_MOD_ID       5701

#ifdef  _BIG_ENDIAN
#define IP_HDR_CSUM_TTL_ADJUST  256
#define IP_TCP_CSUM_COMP    IPPROTO_TCP
#define IP_UDP_CSUM_COMP    IPPROTO_UDP
#else
#define IP_HDR_CSUM_TTL_ADJUST  1
#define IP_TCP_CSUM_COMP    (IPPROTO_TCP << 8)
#define IP_UDP_CSUM_COMP    (IPPROTO_UDP << 8)
#endif

#define TCP_CHECKSUM_OFFSET 16
#define TCP_CHECKSUM_SIZE   2

#define UDP_CHECKSUM_OFFSET 6
#define UDP_CHECKSUM_SIZE   2

#define IPH_TCPH_CHECKSUMP(ipha, hlen)  \
    ((uint16_t *)(((uchar_t *)(ipha)) + ((hlen) + TCP_CHECKSUM_OFFSET)))

#define IPH_UDPH_CHECKSUMP(ipha, hlen)  \
    ((uint16_t *)(((uchar_t *)(ipha)) + ((hlen) + UDP_CHECKSUM_OFFSET)))

#define ILL_HCKSUM_CAPABLE(ill)     \
    (((ill)->ill_capabilities & ILL_CAPAB_HCKSUM) != 0)
/*
 * Macro that performs software checksum calculation on the IP header.
 */
#define IP_HDR_CKSUM(ipha, sum, v_hlen_tos_len, ttl_protocol) {     \
    (sum) += (ttl_protocol) + (ipha)->ipha_ident +          \
        ((v_hlen_tos_len) >> 16) +                  \
        ((v_hlen_tos_len) & 0xFFFF) +               \
        (ipha)->ipha_fragment_offset_and_flags;         \
    (sum) = (((sum) & 0xFFFF) + ((sum) >> 16));         \
    (sum) = ~((sum) + ((sum) >> 16));               \
    (ipha)->ipha_hdr_checksum = (uint16_t)(sum);            \
}

#define IS_IP_HDR_HWCKSUM(ipsec, mp, ill)               \
    ((!ipsec) && (DB_CKSUMFLAGS(mp) & HCK_IPV4_HDRCKSUM) &&     \
    ILL_HCKSUM_CAPABLE(ill) && dohwcksum)

/*
 * This macro acts as a wrapper around IP_CKSUM_XMIT_FAST, and it performs
 * several checks on the IRE and ILL (among other things) in order to see
 * whether or not hardware checksum offload is allowed for the outgoing
 * packet.  It assumes that the caller has held a reference to the IRE.
 */
#define IP_CKSUM_XMIT(ill, ire, mp, ihp, up, proto, start, end,     \
        max_frag, ipsec_len, pseudo) {              \
    uint32_t _hck_flags;                        \
    /*                              \
     * We offload checksum calculation to hardware when IPsec isn't \
     * present and if fragmentation isn't required.  We also check  \
     * if M_DATA fastpath is safe to be used on the corresponding   \
     * IRE; this check is performed without grabbing ire_lock but   \
     * instead by holding a reference to it.  This is sufficient    \
     * for IRE_CACHE; for IRE_BROADCAST on non-Ethernet links, the  \
     * DL_NOTE_FASTPATH_FLUSH indication could come up from the \
     * driver and trigger the IRE (hence fp_mp) deletion.  This is  \
     * why only IRE_CACHE type is eligible for offload.     \
     *                              \
     * The presense of IP options also forces the network stack to  \
     * calculate the checksum in software.  This is because:    \
     *                              \
     * Wrap around: certain partial-checksum NICs (eri, ce) limit   \
     * the size of "start offset" width to 6-bit.  This effectively \
     * sets the largest value of the offset to 64-bytes, starting   \
     * from the MAC header.  When the cumulative MAC and IP headers \
     * exceed such limit, the offset will wrap around.  This causes \
     * the checksum to be calculated at the wrong place.        \
     *                              \
     * IPv4 source routing: none of the full-checksum capable NICs  \
     * is capable of correctly handling the IPv4 source-routing \
     * option for purposes of calculating the pseudo-header; the    \
     * actual destination is different from the destination in the  \
     * header which is that of the next-hop.  (This case may not be \
     * true for NICs which can parse IPv6 extension headers, but    \
     * we choose to simplify the implementation by not offloading   \
     * checksum when they are present.)             \
     *                              \
     */                             \
    if ((ill) != NULL && ILL_HCKSUM_CAPABLE(ill) &&         \
        !((ire)->ire_flags & RTF_MULTIRT) &&            \
        (!((ire)->ire_type & IRE_BROADCAST) ||          \
        (ill)->ill_type == IFT_ETHER) &&            \
        (ipsec_len) == 0 &&                     \
        (((ire)->ire_ipversion == IPV4_VERSION &&           \
        (start) == IP_SIMPLE_HDR_LENGTH &&              \
        ((ire)->ire_nce != NULL &&                  \
        (ire)->ire_nce->nce_fp_mp != NULL &&    \
        MBLKHEAD(mp) >= MBLKL((ire)->ire_nce->nce_fp_mp))) ||   \
        ((ire)->ire_ipversion == IPV6_VERSION &&            \
        (start) == IPV6_HDR_LEN &&                  \
        (ire)->ire_nce->nce_fp_mp != NULL &&            \
        MBLKHEAD(mp) >= MBLKL((ire)->ire_nce->nce_fp_mp))) &&   \
        (max_frag) >= (uint_t)((end) + (ipsec_len)) &&      \
        dohwcksum) {                        \
        _hck_flags = (ill)->ill_hcksum_capab->ill_hcksum_txflags; \
    } else {                            \
        _hck_flags = 0;                     \
    }                               \
    IP_CKSUM_XMIT_FAST((ire)->ire_ipversion, _hck_flags, mp, ihp,   \
        up, proto, start, end, pseudo);             \
}

/*
 * Based on the device capabilities, this macro either marks an outgoing
 * packet with hardware checksum offload information or calculate the
 * checksum in software.  If the latter is performed, the checksum field
 * of the dblk is cleared; otherwise it will be non-zero and contain the
 * necessary flag(s) for the driver.
 */
#define IP_CKSUM_XMIT_FAST(ipver, hck_flags, mp, ihp, up, proto, start, \
        end, pseudo) {                      \
    uint32_t _sum;                          \
    /*                              \
     * Underlying interface supports hardware checksum offload for  \
     * the payload; leave the payload checksum for the hardware to  \
     * calculate.  N.B: We only need to set up checksum info on the \
     * first mblk.                          \
     */                             \
    DB_CKSUMFLAGS(mp) = 0;                      \
    if (((ipver) == IPV4_VERSION &&                 \
        ((hck_flags) & HCKSUM_INET_FULL_V4)) ||         \
        ((ipver) == IPV6_VERSION &&                 \
        ((hck_flags) & HCKSUM_INET_FULL_V6))) {         \
        /*                          \
         * Hardware calculates pseudo-header, header and the    \
         * payload checksums, so clear the checksum field in    \
         * the protocol header.                 \
         */                         \
        *(up) = 0;                      \
        DB_CKSUMFLAGS(mp) |= HCK_FULLCKSUM;         \
    } else if ((hck_flags) & HCKSUM_INET_PARTIAL)  {        \
        /*                          \
         * Partial checksum offload has been enabled.  Fill \
         * the checksum field in the protocl header with the    \
         * pseudo-header checksum value.            \
         */                         \
        _sum = ((proto) == IPPROTO_UDP) ?           \
            IP_UDP_CSUM_COMP : IP_TCP_CSUM_COMP;        \
        _sum += *(up) + (pseudo);               \
        _sum = (_sum & 0xFFFF) + (_sum >> 16);          \
        *(up) = (_sum & 0xFFFF) + (_sum >> 16);         \
        /*                          \
         * Offsets are relative to beginning of IP header.  \
         */                         \
        DB_CKSUMSTART(mp) = (start);                \
        DB_CKSUMSTUFF(mp) = ((proto) == IPPROTO_UDP) ?      \
            (start) + UDP_CHECKSUM_OFFSET :         \
            (start) + TCP_CHECKSUM_OFFSET;          \
        DB_CKSUMEND(mp) = (end);                \
        DB_CKSUMFLAGS(mp) |= HCK_PARTIALCKSUM;          \
    } else {                            \
        /*                          \
         * Software checksumming.               \
         */                         \
        _sum = ((proto) == IPPROTO_UDP) ?           \
            IP_UDP_CSUM_COMP : IP_TCP_CSUM_COMP;        \
        _sum += (pseudo);                   \
        _sum = IP_CSUM(mp, start, _sum);            \
        *(up) = (uint16_t)(((proto) == IPPROTO_UDP) ?       \
            (_sum ? _sum : ~_sum) : _sum);          \
    }                               \
    /*                              \
     * Hardware supports IP header checksum offload; clear the  \
     * contents of IP header checksum field as expected by NIC. \
     * Do this only if we offloaded either full or partial sum. \
     */                             \
    if ((ipver) == IPV4_VERSION && DB_CKSUMFLAGS(mp) != 0 &&    \
        ((hck_flags) & HCKSUM_IPHDRCKSUM)) {            \
        DB_CKSUMFLAGS(mp) |= HCK_IPV4_HDRCKSUM;         \
        ((ipha_t *)(ihp))->ipha_hdr_checksum = 0;       \
    }                               \
}

/*
 * Macro to inspect the checksum of a fully-reassembled incoming datagram.
 */
#define IP_CKSUM_RECV_REASS(hck_flags, off, pseudo, sum, err) {     \
    (err) = B_FALSE;                        \
    if ((hck_flags) & HCK_FULLCKSUM) {              \
        /*                          \
         * The sum of all fragment checksums should     \
         * result in -0 (0xFFFF) or otherwise invalid.      \
         */                         \
        if ((sum) != 0xFFFF)                    \
            (err) = B_TRUE;                 \
    } else if ((hck_flags) & HCK_PARTIALCKSUM) {            \
        (sum) += (pseudo);                  \
        (sum) = ((sum) & 0xFFFF) + ((sum) >> 16);       \
        (sum) = ((sum) & 0xFFFF) + ((sum) >> 16);       \
        if (~(sum) & 0xFFFF)                    \
            (err) = B_TRUE;                 \
    } else if (((sum) = IP_CSUM(mp, off, pseudo)) != 0) {       \
        (err) = B_TRUE;                     \
    }                               \
}

/*
 * This macro inspects an incoming packet to see if the checksum value
 * contained in it is valid; if the hardware has provided the information,
 * the value is verified, otherwise it performs software checksumming.
 * The checksum value is returned to caller.
 */
#define IP_CKSUM_RECV(hck_flags, sum, cksum_start, ulph_off, mp, mp1, err) { \
    int32_t _len;                           \
                                    \
    (err) = B_FALSE;                        \
    if ((hck_flags) & HCK_FULLCKSUM) {              \
        /*                          \
         * Full checksum has been computed by the hardware  \
         * and has been attached.  If the driver wants us to    \
         * verify the correctness of the attached value, in \
         * order to protect against faulty hardware, compare    \
         * it against -0 (0xFFFF) to see if it's valid.     \
         */                         \
        (sum) = DB_CKSUM16(mp);                 \
        if (!((hck_flags) & HCK_FULLCKSUM_OK) && (sum) != 0xFFFF) \
            (err) = B_TRUE;                 \
    } else if (((hck_flags) & HCK_PARTIALCKSUM) &&          \
        ((mp1) == NULL || (mp1)->b_cont == NULL) &&         \
        (ulph_off) >= DB_CKSUMSTART(mp) &&              \
        ((_len = (ulph_off) - DB_CKSUMSTART(mp)) & 1) == 0) {   \
        uint32_t _adj;                      \
        /*                          \
         * Partial checksum has been calculated by hardware \
         * and attached to the packet; in addition, any     \
         * prepended extraneous data is even byte aligned,  \
         * and there are at most two mblks associated with  \
         * the packet.  If any such data exists, we adjust  \
         * the checksum; also take care any postpended data.    \
         */                         \
        IP_ADJCKSUM_PARTIAL(cksum_start, mp, mp1, _len, _adj);  \
        /*                          \
         * One's complement subtract extraneous checksum    \
         */                         \
        (sum) += DB_CKSUM16(mp);                \
        if (_adj >= (sum))                  \
            (sum) = ~(_adj - (sum)) & 0xFFFF;       \
        else                            \
            (sum) -= _adj;                  \
        (sum) = ((sum) & 0xFFFF) + ((int)(sum) >> 16);      \
        (sum) = ((sum) & 0xFFFF) + ((int)(sum) >> 16);      \
        if (~(sum) & 0xFFFF)                    \
            (err) = B_TRUE;                 \
    } else if (((sum) = IP_CSUM(mp, ulph_off, sum)) != 0) {     \
        (err) = B_TRUE;                     \
    }                               \
}

/*
 * Macro to adjust a given checksum value depending on any prepended
 * or postpended data on the packet.  It expects the start offset to
 * begin at an even boundary and that the packet consists of at most
 * two mblks.
 */
#define IP_ADJCKSUM_PARTIAL(cksum_start, mp, mp1, len, adj) {       \
    /*                              \
     * Prepended extraneous data; adjust checksum.          \
     */                             \
    if ((len) > 0)                          \
        (adj) = IP_BCSUM_PARTIAL(cksum_start, len, 0);      \
    else                                \
        (adj) = 0;                      \
    /*                              \
     * len is now the total length of mblk(s)           \
     */                             \
    (len) = MBLKL(mp);                      \
    if ((mp1) == NULL)                      \
        (mp1) = (mp);                       \
    else                                \
        (len) += MBLKL(mp1);                    \
    /*                              \
     * Postpended extraneous data; adjust checksum.         \
     */                             \
    if (((len) = (DB_CKSUMEND(mp) - len)) > 0) {            \
        uint32_t _pad;                      \
                                    \
        _pad = IP_BCSUM_PARTIAL((mp1)->b_wptr, len, 0);     \
        /*                          \
         * If the postpended extraneous data was odd        \
         * byte aligned, swap resulting checksum bytes.     \
         */                         \
        if ((uintptr_t)(mp1)->b_wptr & 1)           \
            (adj) += ((_pad << 8) & 0xFFFF) | (_pad >> 8);  \
        else                            \
            (adj) += _pad;                  \
        (adj) = ((adj) & 0xFFFF) + ((int)(adj) >> 16);      \
    }                               \
}

#define ILL_MDT_CAPABLE(ill)        \
    (((ill)->ill_capabilities & ILL_CAPAB_MDT) != 0)

/*
 * ioctl identifier and structure for Multidata Transmit update
 * private M_CTL communication from IP to ULP.
 */
#define MDT_IOC_INFO_UPDATE (('M' << 8) + 1020)

typedef struct ip_mdt_info_s {
    uint_t  mdt_info_id;    /* MDT_IOC_INFO_UPDATE */
    ill_mdt_capab_t mdt_capab; /* ILL MDT capabilities */
} ip_mdt_info_t;

/*
 * Macro that determines whether or not a given ILL is allowed for MDT.
 */
#define ILL_MDT_USABLE(ill)                     \
    (ILL_MDT_CAPABLE(ill) &&                    \
    ill->ill_mdt_capab != NULL &&                   \
    ill->ill_mdt_capab->ill_mdt_version == MDT_VERSION_2 &&     \
    ill->ill_mdt_capab->ill_mdt_on != 0)

#define ILL_LSO_CAPABLE(ill)        \
    (((ill)->ill_capabilities & ILL_CAPAB_LSO) != 0)

/*
 * ioctl identifier and structure for Large Segment Offload
 * private M_CTL communication from IP to ULP.
 */
#define LSO_IOC_INFO_UPDATE (('L' << 24) + ('S' << 16) + ('O' << 8))

typedef struct ip_lso_info_s {
    uint_t  lso_info_id;    /* LSO_IOC_INFO_UPDATE */
    ill_lso_capab_t lso_capab; /* ILL LSO capabilities */
} ip_lso_info_t;

/*
 * Macro that determines whether or not a given ILL is allowed for LSO.
 */
#define ILL_LSO_USABLE(ill)                     \
    (ILL_LSO_CAPABLE(ill) &&                    \
    ill->ill_lso_capab != NULL &&                   \
    ill->ill_lso_capab->ill_lso_version == LSO_VERSION_1 &&     \
    ill->ill_lso_capab->ill_lso_on != 0)

#define ILL_LSO_TCP_USABLE(ill)                     \
    (ILL_LSO_USABLE(ill) &&                     \
    ill->ill_lso_capab->ill_lso_flags & LSO_TX_BASIC_TCP_IPV4)

/*
 * Macro that determines whether or not a given CONN may be considered
 * for fast path prior to proceeding further with LSO or Multidata.
 */
#define CONN_IS_LSO_MD_FASTPATH(connp)  \
    ((connp)->conn_dontroute == 0 &&    /* SO_DONTROUTE */  \
    !((connp)->conn_nexthop_set) &&     /* IP_NEXTHOP */    \
    (connp)->conn_nofailover_ill == NULL && /* IPIF_NOFAILOVER */   \
    (connp)->conn_outgoing_pill == NULL &&  /* IP{V6}_BOUND_PIF */  \
    (connp)->conn_outgoing_ill == NULL) /* IP{V6}_BOUND_IF */

/* Definitons for fragmenting IP packets using MDT. */

/*
 * Smaller and private version of pdescinfo_t used specifically for IP,
 * which allows for only a single payload span per packet.
 */
typedef struct ip_pdescinfo_s PDESCINFO_STRUCT(2)   ip_pdescinfo_t;

/*
 * Macro version of ip_can_frag_mdt() which avoids the function call if we
 * only examine a single message block.
 */
#define IP_CAN_FRAG_MDT(mp, hdr_len, len)           \
    (((mp)->b_cont == NULL) ?               \
    (MBLKL(mp) >= ((hdr_len) + ip_wput_frag_mdt_min)) : \
    ip_can_frag_mdt((mp), (hdr_len), (len)))

/*
 * Macro that determines whether or not a given IPC requires
 * outbound IPSEC processing.
 */
#define CONN_IPSEC_OUT_ENCAPSULATED(connp)  \
    ((connp)->conn_out_enforce_policy ||    \
    ((connp)->conn_latch != NULL &&     \
    (connp)->conn_latch->ipl_out_policy != NULL))

/*
 * These are used by the synchronous streams code in tcp and udp.
 * When we set the flags for a wakeup from a synchronous stream we
 * always set RSLEEP in sd_wakeq, even if we have a read thread waiting
 * to do the io. This is in case the read thread gets interrupted
 * before completing the io. The RSLEEP flag in sd_wakeq is used to
 * indicate that there is data available at the synchronous barrier.
 * The assumption is that subsequent functions calls through rwnext()
 * will reset sd_wakeq appropriately.
 */
#define STR_WAKEUP_CLEAR(stp) {                     \
    mutex_enter(&stp->sd_lock);                 \
    stp->sd_wakeq &= ~RSLEEP;                   \
    mutex_exit(&stp->sd_lock);                  \
}

#define STR_WAKEUP_SET(stp) {                       \
    mutex_enter(&stp->sd_lock);                 \
    if (stp->sd_flag & RSLEEP) {                    \
        stp->sd_flag &= ~RSLEEP;                \
        cv_broadcast(&_RD(stp->sd_wrq)->q_wait);        \
    }                               \
    stp->sd_wakeq |= RSLEEP;                    \
    mutex_exit(&stp->sd_lock);                  \
}

#define STR_SENDSIG(stp) {                      \
    int _events;                            \
    mutex_enter(&stp->sd_lock);                 \
    if ((_events = stp->sd_sigflags & (S_INPUT | S_RDNORM)) != 0)   \
        strsendsig(stp->sd_siglist, _events, 0, 0);     \
    if (stp->sd_rput_opt & SR_POLLIN) {             \
        stp->sd_rput_opt &= ~SR_POLLIN;             \
        mutex_exit(&stp->sd_lock);              \
        pollwakeup(&stp->sd_pollist, POLLIN | POLLRDNORM);  \
    } else {                            \
        mutex_exit(&stp->sd_lock);              \
    }                               \
}

#define CONN_UDP_SYNCSTR(connp)                     \
    (IPCL_IS_UDP(connp) && (connp)->conn_udp->udp_direct_sockfs)

/*
 * Macro that checks whether or not a particular UDP conn is
 * flow-controlling on the read-side.  If udp module is directly
 * above ip, check to see if the drain queue is full; note here
 * that we check this without any lock protection because this
 * is a coarse granularity inbound flow-control.  If the module
 * above ip is not udp, then use canputnext to determine the
 * flow-control.
 *
 * Note that these checks are done after the conn is found in
 * the UDP fanout table.
 * FIXME? Might be faster to check both udp_drain_qfull and canputnext.
 */
#define CONN_UDP_FLOWCTLD(connp)                    \
    (CONN_UDP_SYNCSTR(connp) ?                  \
    (connp)->conn_udp->udp_drain_qfull :                \
    !canputnext((connp)->conn_rq))

#define ILL_DLS_CAPABLE(ill)    \
    (((ill)->ill_capabilities &     \
    (ILL_CAPAB_POLL|ILL_CAPAB_SOFT_RING)) != 0)

/*
 * Macro that hands off one or more messages directly to DLD
 * when the interface is marked with ILL_CAPAB_POLL.
 */
#define IP_DLS_ILL_TX(ill, ipha, mp, ipst) {                \
    ill_dls_capab_t *ill_dls = ill->ill_dls_capab;          \
    ASSERT(ILL_DLS_CAPABLE(ill));                   \
    ASSERT(ill_dls != NULL);                    \
    ASSERT(ill_dls->ill_tx != NULL);                \
    ASSERT(ill_dls->ill_tx_handle != NULL);             \
    DTRACE_PROBE4(ip4__physical__out__start,            \
        ill_t *, NULL, ill_t *, ill,                \
        ipha_t *, ipha, mblk_t *, mp);              \
    FW_HOOKS(ipst->ips_ip4_physical_out_event,          \
        ipst->ips_ipv4firewall_physical_out,            \
        NULL, ill, ipha, mp, mp, 0, ipst);              \
    DTRACE_PROBE1(ip4__physical__out__end, mblk_t *, mp);       \
    if (mp != NULL) {                       \
        DTRACE_IP7(send, mblk_t *, mp, conn_t *, NULL,      \
            void_ip_t *, ipha, __dtrace_ipsr_ill_t *, ill,  \
            ipha_t *, ipha, ip6_t *, NULL, int, 0);     \
        ill_dls->ill_tx(ill_dls->ill_tx_handle, mp);        \
    }                               \
}

extern int  ip_wput_frag_mdt_min;
extern boolean_t ip_can_frag_mdt(mblk_t *, ssize_t, ssize_t);
extern mblk_t   *ip_prepend_zoneid(mblk_t *, zoneid_t, ip_stack_t *);

#endif  /* _KERNEL */

#ifdef  __cplusplus
}
#endif

#endif  /* _INET_IP_IMPL_H */