/*
 * Copyright 2000, International Business Machines Corporation and others.
 * All Rights Reserved.
 * 
 * This software has been released under the terms of the IBM Public
 * License.  For details, see the LICENSE file in the top-level source
 * directory or online at http://www.openafs.org/dl/license10.html
 */

/* rx_user.c contains routines specific to the user space UNIX implementation of rx */

# include <afs/param.h>
# include <sys/types.h>
# include <errno.h>
# include <signal.h>
#ifdef AFS_NT40_ENV
# include <WINNT/syscfg.h>
#else
# include <sys/socket.h>
# include <sys/file.h>
# include <netdb.h>
# include <sys/stat.h>
# include <netinet/in.h>
# include <sys/time.h>
# include <net/if.h>
# include <sys/ioctl.h>
#endif
# include <fcntl.h>
#if !defined(AFS_AIX_ENV) && !defined(AFS_NT40_ENV)
# include <sys/syscall.h>
#endif
#include <afs/afs_args.h>
#include <afs/afsutil.h>

#ifndef	IPPORT_USERRESERVED
/* If in.h doesn't define this, define it anyway.  Unfortunately, defining
   this doesn't put the code into the kernel to restrict kernel assigned
   port numbers to numbers below IPPORT_USERRESERVED...  */
#define IPPORT_USERRESERVED 5000
# endif

#ifndef AFS_NT40_ENV
# include <sys/time.h>
#endif
# include "rx.h"
# include "rx_globals.h"


extern void rxi_Delay();

#ifdef AFS_PTHREAD_ENV
#include <assert.h>

/*
 * The rx_if_init_mutex mutex protects the following global variables:
 * Inited
 */

pthread_mutex_t rx_if_init_mutex;
#define LOCK_IF_INIT assert(pthread_mutex_lock(&rx_if_init_mutex)==0);
#define UNLOCK_IF_INIT assert(pthread_mutex_unlock(&rx_if_init_mutex)==0);

/*
 * The rx_if_mutex mutex protects the following global variables:
 * myNetFlags
 * myNetMTUs
 * myNetMasks
 */

pthread_mutex_t rx_if_mutex;
#define LOCK_IF assert(pthread_mutex_lock(&rx_if_mutex)==0);
#define UNLOCK_IF assert(pthread_mutex_unlock(&rx_if_mutex)==0);
#else
#define LOCK_IF_INIT
#define UNLOCK_IF_INIT
#define LOCK_IF
#define UNLOCK_IF
#endif /* AFS_PTHREAD_ENV */


/*
 * Make a socket for receiving/sending IP packets.  Set it into non-blocking
 * and large buffering modes.  If port isn't specified, the kernel will pick
 * one.  Returns the socket (>= 0) on success.  Returns OSI_NULLSOCKET on
 * failure. Port must be in network byte order.	
 */
osi_socket rxi_GetUDPSocket(u_short port)
{
    int binds, code;
    osi_socket socketFd = OSI_NULLSOCKET;
    struct sockaddr_in taddr;
    char *name = "rxi_GetUDPSocket: ";
    extern int rxi_Listen(osi_socket sock);
    int greedy;

#ifndef AFS_NT40_ENV
    if (ntohs(port) >= IPPORT_RESERVED && ntohs(port) < IPPORT_USERRESERVED) {
/*	(osi_Msg "%s*WARNING* port number %d is not a reserved port number.  Use port numbers above %d\n", name, port, IPPORT_USERRESERVED);
*/ ;
    }
    if (ntohs(port) > 0 && ntohs(port) < IPPORT_RESERVED && geteuid() != 0) {
	(osi_Msg "%sport number %d is a reserved port number which may only be used by root.  Use port numbers above %d\n", name, ntohs(port), IPPORT_USERRESERVED);
	goto error;
    }
#endif
    socketFd = socket(AF_INET, SOCK_DGRAM, 0);

    if (socketFd < 0) {
	perror("socket");
	goto error;
    }

    taddr.sin_addr.s_addr = 0;
    taddr.sin_family = AF_INET;
    taddr.sin_port = (u_short)port;
#define MAX_RX_BINDS 10
    for (binds=0; binds<MAX_RX_BINDS; binds++) {
      if (binds) rxi_Delay (10);
      code = bind(socketFd, (struct sockaddr *) &taddr, sizeof(taddr));
      if (!code) break;
    }
    if (code) {
      perror("bind");
      (osi_Msg "%sbind failed\n", name);
      goto error;
    }

#ifndef AFS_NT40_ENV
    /*
     * Set close-on-exec on rx socket 
     */
    fcntl(socketFd, F_SETFD, 1);
#endif

    /* Use one of three different ways of getting a socket buffer expanded to
     * a reasonable size.
     */
    {
	int len1, len2;

	len1 = 32766;
	len2 = rx_UdpBufSize;
	greedy = 
	  (setsockopt(socketFd, SOL_SOCKET, SO_RCVBUF, (char *)&len2,
		      sizeof(len2)) >= 0);
        if (!greedy) {
	  len2=32766;  /* fall back to old size... uh-oh! */
	}

	greedy =
	  (setsockopt(socketFd, SOL_SOCKET, SO_SNDBUF, (char *)&len1,
		      sizeof(len1)) >= 0) &&
	  (setsockopt(socketFd, SOL_SOCKET, SO_RCVBUF, (char *)&len2,
		      sizeof(len2)) >= 0);
    }

    if (!greedy)
	(osi_Msg "%s*WARNING* Unable to increase buffering on socket\n", name);
    if (rxi_Listen(socketFd) < 0) {
	goto error;
    }

    return socketFd;

error:
#ifdef AFS_NT40_ENV
    if (socketFd >= 0) closesocket(socketFd);
#else
    if (socketFd >= 0) close(socketFd);
#endif

    MUTEX_ENTER(&rx_stats_mutex);
    rx_stats.socketGreedy = greedy;
    MUTEX_EXIT(&rx_stats_mutex);
    return OSI_NULLSOCKET;
}

void osi_Panic(msg, a1, a2, a3)
    char *msg;
{
    (osi_Msg "Fatal Rx error: ");
    (osi_Msg msg, a1, a2, a3);
    fflush(stderr);
    fflush(stdout);
    afs_abort();
}

/*
 * osi_AssertFailU() -- used by the osi_Assert() macro.
 */

void osi_AssertFailU(const char *expr, const char *file, int line)
{
    osi_Panic("assertion failed: %s, file: %s, line: %d\n", expr, file, line);
}

#ifdef	AFS_AIX32_ENV
#ifndef osi_Alloc
static const char memZero;
char * osi_Alloc(x)
    afs_int32 x; 
{
    /* 
     * 0-length allocs may return NULL ptr from osi_kalloc, so we special-case
     * things so that NULL returned iff an error occurred 
     */
    if (x == 0) return &memZero;
    return ((char *) malloc(x));
}

osi_Free(x, size)
    char *x;
    afs_int32 size; 
{
    if (x == &memZero) return;
    free((char *)x);
}
#endif
#endif /* AFS_AIX32_ENV */

#define	ADDRSPERSITE	16


afs_uint32 rxi_NetAddrs[ADDRSPERSITE]; /* host order */
static int myNetMTUs[ADDRSPERSITE];
static int myNetMasks[ADDRSPERSITE];
static int myNetFlags[ADDRSPERSITE];
u_int rxi_numNetAddrs;
static int Inited = 0;

#if defined(AFS_NT40_ENV)
int rxi_getaddr(void)
{
    if (rxi_numNetAddrs > 0)
	return htonl(rxi_NetAddrs[0]);
    else
	return 0;
}

/* 
** return number of addresses 
** and the addresses themselves in the buffer
** maxSize - max number of interfaces to return.
*/
int rx_getAllAddr (afs_int32 *buffer, int maxSize)
{
    int count = 0;
    for (count = 0; count < rxi_numNetAddrs && maxSize > 0; count++, maxSize--)
	buffer[count] = htonl(rxi_NetAddrs[count]);

    return count;
}

#endif

#ifdef AFS_NT40_ENV

void rx_GetIFInfo(void)
{
    LOCK_IF_INIT
    if (Inited) {
	UNLOCK_IF_INIT
	return;
    }
    else {
	u_int maxsize;
	u_int rxsize;
	int npackets, ncbufs;
	afs_uint32 i;

	Inited = 1;
	UNLOCK_IF_INIT
	rxi_numNetAddrs = ADDRSPERSITE;

	LOCK_IF
	(void) syscfg_GetIFInfo(&rxi_numNetAddrs, rxi_NetAddrs,
				myNetMasks, myNetMTUs, myNetFlags);

	for (i=0; i<rxi_numNetAddrs; i++) {
	    rxsize = rxi_AdjustIfMTU(myNetMTUs[i] - RX_IPUDP_SIZE);
	    maxsize = rxi_nRecvFrags*rxsize + (rxi_nRecvFrags-1)*UDP_HDR_SIZE;
	    maxsize = rxi_AdjustMaxMTU(rxsize, maxsize);
	    if (rx_maxReceiveSize < maxsize)  {
		rx_maxReceiveSize = MIN( RX_MAX_PACKET_SIZE, maxsize);
		rx_maxReceiveSize = MIN( rx_maxReceiveSize,
					 rx_maxReceiveSizeUser);
	    }

	}
	UNLOCK_IF
	ncbufs = (rx_maxJumboRecvSize - RX_FIRSTBUFFERSIZE);
	if (ncbufs > 0) {
	    ncbufs = ncbufs / RX_CBUFFERSIZE;
	    npackets = rx_initSendWindow -1;
	    rxi_MorePackets(npackets*(ncbufs+1));
	}
    }
}
    
#endif

static afs_uint32 fudge_netmask(addr) 
afs_uint32 addr;
{
afs_uint32 msk;

    if (IN_CLASSA(addr)) msk = IN_CLASSA_NET;
    else if (IN_CLASSB(addr)) msk = IN_CLASSB_NET;
    else if (IN_CLASSC(addr)) msk = IN_CLASSC_NET;
    else msk = 0;

return msk;
}



#if !defined(AFS_AIX_ENV) && !defined(AFS_NT40_ENV) && !defined(AFS_LINUX20_ENV)
int rxi_syscall(a3, a4, a5)
afs_uint32 a3, a4;
void * a5;
{
  afs_uint32 rcode;
  void (*old)();
	
  old = (void (*)())signal(SIGSYS, SIG_IGN);	

#if defined(AFS_SGI_ENV)
  rcode = afs_syscall(a3, a4, a5);
#else
  rcode = syscall (AFS_SYSCALL, 28 /* AFSCALL_CALL */, a3, a4, a5);
#endif /* AFS_SGI_ENV */

  signal(SIGSYS, old);	

return rcode;
}
#endif /* AFS_AIX_ENV */

#ifndef AFS_NT40_ENV
void rx_GetIFInfo()
{
    int     s;
    int     i, j, len, res;
    struct ifconf   ifc;
    struct ifreq    ifs[ADDRSPERSITE];
    struct ifreq ifreq, *ifr;
#ifdef	AFS_AIX41_ENV
    char buf[BUFSIZ], *cp, *cplim;
#endif
    struct sockaddr_in *a;

    LOCK_IF_INIT
    if (Inited) {
      UNLOCK_IF_INIT
      return;
    }
    Inited = 1;
    UNLOCK_IF_INIT

    LOCK_IF
    rxi_numNetAddrs = 0;
    bzero(rxi_NetAddrs, sizeof(rxi_NetAddrs));
    bzero(myNetFlags, sizeof(myNetFlags));
    bzero(myNetMTUs, sizeof(myNetMTUs));
    bzero(myNetMasks, sizeof(myNetMasks));
    UNLOCK_IF

    s = socket(AF_INET, SOCK_DGRAM, 0);
    if (s < 0) return;

#ifdef	AFS_AIX41_ENV
    ifc.ifc_len = sizeof (buf);
    ifc.ifc_buf = buf;
    ifr = ifc.ifc_req;
#else
    ifc.ifc_len = sizeof(ifs);
    ifc.ifc_buf = (caddr_t) &ifs[0];
    bzero(&ifs[0], sizeof(ifs));
#endif 
    res = ioctl(s, SIOCGIFCONF, &ifc);
    if (res < 0) {
      /* fputs(stderr, "ioctl error IFCONF\n"); */
      close(s);
      return;
    }

    LOCK_IF

#ifdef	AFS_AIX41_ENV
#define size(p) MAX((p).sa_len, sizeof(p))
    cplim = buf + ifc.ifc_len; /*skip over if's with big ifr_addr's */
    for (cp = buf; cp < cplim ;
	 cp += sizeof(ifr->ifr_name) + MAX(a->sin_len, sizeof(*a))) {
	if (rxi_numNetAddrs >= ADDRSPERSITE)
	    break;

	ifr = (struct ifreq *)cp;
#else
    len = ifc.ifc_len / sizeof(struct ifreq);
    if (len > ADDRSPERSITE)
      len = ADDRSPERSITE;

    for (i = 0; i < len; ++i) {
	ifr = &ifs[i];
	res = ioctl(s, SIOCGIFADDR, ifr);
#endif
	if (res < 0) {
	  /* fputs(stderr, "ioctl error IFADDR\n");
	    perror(ifr->ifr_name);   */
	  continue;
	}
	a = (struct sockaddr_in *) &ifr->ifr_addr;
	if (a->sin_family != AF_INET) continue;
	rxi_NetAddrs[rxi_numNetAddrs] = ntohl(a->sin_addr.s_addr);
	if (rxi_NetAddrs[rxi_numNetAddrs] == 0x7f000001) {
	  /* we don't really care about "localhost" */
	  continue;
	}
 	for (j=0; j < rxi_numNetAddrs; j++) {
	   if (rxi_NetAddrs[j] == rxi_NetAddrs[rxi_numNetAddrs])
	      break;
	}
	if (j < rxi_numNetAddrs) continue;

	/* fprintf(stderr, "if %s addr=%x\n", ifr->ifr_name,
		rxi_NetAddrs[rxi_numNetAddrs]); */

#ifdef SIOCGIFFLAGS
	res = ioctl(s, SIOCGIFFLAGS, ifr);
	if (res == 0) {
	    myNetFlags[rxi_numNetAddrs] = ifr->ifr_flags;
#ifdef IFF_LOOPBACK
	    /* Handle aliased loopbacks as well. */
	    if (ifr->ifr_flags & IFF_LOOPBACK)
		continue;
#endif
	    /* fprintf(stderr, "if %s flags=%x\n", 
		    ifr->ifr_name, ifr->ifr_flags); */
	}
	else { /*
	  fputs(stderr, "ioctl error IFFLAGS\n");
	  perror(ifr->ifr_name); */
	}
#endif /* SIOCGIFFLAGS */

#if !defined(AFS_AIX_ENV)  && !defined(AFS_LINUX20_ENV)
	/* this won't run on an AIX system w/o a cache manager */
	rxi_syscallp = rxi_syscall;
#endif

	/* If I refer to kernel extensions that aren't loaded on AIX, the 
	 * program refuses to load and run, so I simply can't include the 
	 * following code.  Fortunately, AIX is the one operating system in
	 * which the subsequent ioctl works reliably. */
	if (rxi_syscallp) {
	  if ((*rxi_syscallp)( 20 /*AFSOP_GETMTU*/,  
			      htonl(rxi_NetAddrs[rxi_numNetAddrs]),
			      &(myNetMTUs[rxi_numNetAddrs]))) {
	    /* fputs(stderr, "syscall error GETMTU\n");
	       perror(ifr->ifr_name); */
	    myNetMTUs[rxi_numNetAddrs] = 0;
	  }
	  if ((*rxi_syscallp)(42 /*AFSOP_GETMASK*/,  
			      htonl(rxi_NetAddrs[rxi_numNetAddrs]),
			      &(myNetMasks[rxi_numNetAddrs]))) {
	    /* fputs(stderr, "syscall error GETMASK\n");
	       perror(ifr->ifr_name); */
	    myNetMasks[rxi_numNetAddrs] = 0;
	  }
	  else myNetMasks[rxi_numNetAddrs] = ntohl( myNetMasks[rxi_numNetAddrs]);
	   /* fprintf(stderr, "if %s mask=0x%x\n", 
	     ifr->ifr_name, myNetMasks[rxi_numNetAddrs]);*/
	}

	if (myNetMTUs[rxi_numNetAddrs] == 0) {
	  myNetMTUs[rxi_numNetAddrs] = OLD_MAX_PACKET_SIZE + RX_IPUDP_SIZE;
#ifdef SIOCGIFMTU
	  res = ioctl(s, SIOCGIFMTU, ifr);
	  if ((res == 0) && (ifr->ifr_metric > 128))  { /* sanity check */
	    myNetMTUs[rxi_numNetAddrs] = ifr->ifr_metric;
	    /* fprintf(stderr, "if %s mtu=%d\n", 
		    ifr->ifr_name, ifr->ifr_metric); */
	  }
	  else {
	    /* fputs(stderr, "ioctl error IFMTU\n");
	       perror(ifr->ifr_name); */
	  }
#endif
	}

	if (myNetMasks[rxi_numNetAddrs] == 0) {
	  myNetMasks[rxi_numNetAddrs] = fudge_netmask(rxi_NetAddrs[rxi_numNetAddrs]);
#ifdef SIOCGIFNETMASK
	  res = ioctl(s, SIOCGIFNETMASK, ifr);
	  if ((res == 0)) {
	    a = (struct sockaddr_in *) &ifr->ifr_addr;
	    myNetMasks[rxi_numNetAddrs] = ntohl(a->sin_addr.s_addr);
	    /* fprintf(stderr, "if %s subnetmask=0x%x\n", 
		    ifr->ifr_name, myNetMasks[rxi_numNetAddrs]); */
	  }
	  else {
	    /* fputs(stderr, "ioctl error IFMASK\n");
	       perror(ifr->ifr_name); */
	  }
#endif
	}

	if (rxi_NetAddrs[rxi_numNetAddrs] != 0x7f000001) { /* ignore lo0 */
	   int maxsize;
	   maxsize = rxi_nRecvFrags*(myNetMTUs[rxi_numNetAddrs] - RX_IP_SIZE);
	   maxsize -= UDP_HDR_SIZE; /* only the first frag has a UDP hdr */
	   if (rx_maxReceiveSize < maxsize) 
		rx_maxReceiveSize = MIN( RX_MAX_PACKET_SIZE, maxsize);
	   ++rxi_numNetAddrs;
	}
    }
    UNLOCK_IF
    close(s);

    /* have to allocate at least enough to allow a single packet to reach its
     * maximum size, so ReadPacket will work.  Allocate enough for a couple
     * of packets to do so, for good measure */
    {
      int npackets, ncbufs;

      rx_maxJumboRecvSize = RX_HEADER_SIZE
			    + rxi_nDgramPackets * RX_JUMBOBUFFERSIZE
			    + (rxi_nDgramPackets-1) * RX_JUMBOHEADERSIZE;
      rx_maxJumboRecvSize = MAX(rx_maxJumboRecvSize, rx_maxReceiveSize);
      ncbufs = (rx_maxJumboRecvSize - RX_FIRSTBUFFERSIZE);
      if (ncbufs > 0) {
	ncbufs = ncbufs / RX_CBUFFERSIZE;
	npackets = rx_initSendWindow -1;
	rxi_MorePackets(npackets*(ncbufs+1));
      }
    }
}
#endif /* AFS_NT40_ENV */

/* Called from rxi_FindPeer, when initializing a clear rx_peer structure,
 * to get interesting information.
 * Curiously enough, the rx_peerHashTable_lock currently protects the
 * Inited variable (and hence rx_GetIFInfo). When the fs suite uses
 * pthreads, this issue will need to be revisited.
 */

void rxi_InitPeerParams(struct rx_peer *pp)
{
    afs_uint32 ppaddr;
    u_short rxmtu;
    int ix;



    LOCK_IF_INIT
    if (!Inited) {
	UNLOCK_IF_INIT
	/*
	 * there's a race here since more than one thread could call
	 * rx_GetIFInfo.  The race stops in rx_GetIFInfo.
	 */
	rx_GetIFInfo();
    } else {
	UNLOCK_IF_INIT
    }

#ifdef ADAPT_MTU
    /* try to second-guess IP, and identify which link is most likely to
     * be used for traffic to/from this host. */
    ppaddr = ntohl(pp->host);

    pp->ifMTU = 0;
    pp->timeout.sec = 2;
    pp->rateFlag = 2;   /* start timing after two full packets */
    /* I don't initialize these, because I presume they are bzero'd... 
     * pp->burstSize pp->burst pp->burstWait.sec pp->burstWait.usec
     * pp->timeout.usec */
  
    LOCK_IF
    for (ix = 0; ix < rxi_numNetAddrs; ++ix) {
      if ((rxi_NetAddrs[ix] & myNetMasks[ix]) == (ppaddr & myNetMasks[ix])) {
#ifdef IFF_POINTOPOINT
	if (myNetFlags[ix] & IFF_POINTOPOINT) 
	   pp->timeout.sec = 4;
#endif /* IFF_POINTOPOINT */
	rxmtu = myNetMTUs[ix] - RX_IPUDP_SIZE;
	if ( rxmtu < RX_MIN_PACKET_SIZE ) 
	  rxmtu = RX_MIN_PACKET_SIZE ;
	if (pp->ifMTU < rxmtu) 
	  pp->ifMTU = MIN(rx_MyMaxSendSize, rxmtu);
      }
    }
    UNLOCK_IF

    if (!pp->ifMTU) { /* not local */
	pp->timeout.sec = 3;
	pp->ifMTU = RX_REMOTE_PACKET_SIZE;
    }
#else /* ADAPT_MTU */
    pp->rateFlag = 2;   /* start timing after two full packets */
    pp->timeout.sec = 2;
    pp->ifMTU = OLD_MAX_PACKET_SIZE;
#endif /* ADAPT_MTU */
    pp->ifMTU = rxi_AdjustIfMTU(pp->ifMTU);
    pp->maxMTU = OLD_MAX_PACKET_SIZE;  /* for compatibility with old guys */
    pp->natMTU = MIN((int)pp->ifMTU, OLD_MAX_PACKET_SIZE); 
    pp->maxDgramPackets = MIN(rxi_nDgramPackets,
			      rxi_AdjustDgramPackets(RX_MAX_FRAGS, pp->ifMTU));
    pp->ifDgramPackets = MIN(rxi_nDgramPackets,
			     rxi_AdjustDgramPackets(RX_MAX_FRAGS, pp->ifMTU));
    pp->maxDgramPackets = 1;
    /* Initialize slow start parameters */
    pp->MTU = MIN(pp->natMTU, pp->maxMTU);
    pp->cwind = 1;
    pp->nDgramPackets = 1;
    pp->congestSeq = 0;
}

/* Don't expose jumobgram internals. */
void rx_SetNoJumbo(void)
{
    rx_maxReceiveSize = OLD_MAX_PACKET_SIZE;
    rxi_nSendFrags = rxi_nRecvFrags = 1;
}