lib/libcs/csopen.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1990-2011 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                 Eclipse Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*          http://www.eclipse.org/org/documents/epl-v10.html           *
*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 * Glenn Fowler
 * AT&T Research
 *
 * access/open/create path of the form
 *
 *  /dev/<type>/<host>/<service>[/<qualifier>][/<perm>][/#option][/#/path]
 *
 * type:    {fdp,tcp,udp}
 * host:    open={<hostname>}, create={share,local}
 * service: {.../lib/cs/<type>/<service>/server,.../bin/<service>}
 * qualifier:   optional service qualifier
 * perm:    {user[=euid],group[=egid],other(default)}
 */

#include "cslib.h"

#include <error.h>
#include <proc.h>
#include <hashkey.h>

#define REMOTE_ARGC 10
#define REMOTE_FLAGC    12

/*
 * create the state->mount <type>/<host>/<service>/<perm> subdirs
 * state->mount modified, possibly destroyed on error
 */

static int
mkmount(register Cs_t* state, int mode, int uid, int gid, char* endserv, char* endhost, char* endtype)
{
    *(state->control - 1) = 0;
    if (eaccess(state->mount, R_OK|W_OK|X_OK))
    {
        if (errno != ENOENT)
            goto bad;
        if (!endserv && !(endserv = strrchr(state->mount, '/')))
            goto bad;
        *endserv = 0;
        if (eaccess(state->mount, X_OK))
        {
            if (!endhost && !(endhost = strrchr(state->mount, '/')))
                goto bad;
            *endhost = 0;
            if (eaccess(state->mount, X_OK))
            {
                if (!endtype && !(endtype = strrchr(state->mount, '/')))
                    goto bad;
                *endtype = 0;
                if (eaccess(state->mount, X_OK) && (mkdir(state->mount, S_IRWXU|S_IRWXG|S_IRWXO) || chmod(state->mount, S_IRWXU|S_IRWXG|S_IRWXO)))
                    goto bad;
                *endtype = '/';
                if (mkdir(state->mount, S_IRWXU|S_IRWXG|S_IRWXO) || chmod(state->mount, S_IRWXU|S_IRWXG|S_IRWXO))
                    goto bad;
            }
            *endhost = '/';
            if (mkdir(state->mount, S_IRWXU|S_IRWXG|S_IRWXO) || chmod(state->mount, S_IRWXU|S_IRWXG|S_IRWXO))
                goto bad;
        }
        *endserv = '/';
        if (mkdir(state->mount, mode))
            goto bad;
        if (mode != (S_IRWXU|S_IRWXG|S_IRWXO) && (uid >= 0 || gid >= 0 && (mode |= S_ISGID)) && (chown(state->mount, uid, gid) || chmod(state->mount, mode)))
        {
            rmdir(state->mount);
            goto bad;
        }
    }
    *(state->control - 1) = '/';
    return 0;
 bad:
    if (endtype && !*endtype)
        *endtype = '/';
    if (endhost && !*endhost)
        *endhost = '/';
    if (endserv && !*endserv)
        *endserv = '/';
    *(state->control - 1) = '/';
    messagef((state->id, NiL, -1, "mkmount: %s: cannot access physical mount directory", state->mount));
    return -1;
}

/*
 * generate CS_REMOTE_CONTROL argv
 */

static void
remote(register Cs_t* state, const char* host, const char* user, const char* path, int agent, register char** av, register char* fv)
{
    register char*  t;

    *av++ = CS_REMOTE_SHELL;
    *av++ = (char*)host;
    if (user && *user)
    {
        *av++ = "-l";
        *av++ = (char*)user;
    }
    *av++ = CS_REMOTE_PROFILE;
    *av++ = ";";
    *av++ = CS_REMOTE_CONTROL;
    *av++ = fv;
    *av++ = (char*)path;
    *av = 0;
    *fv++ = '-';
    if (error_info.trace < 0)
        fv += sfsprintf(fv, 4, "%c%d", CS_REMOTE_DEBUG, -error_info.trace);
    *fv++ = CS_REMOTE_OPEN;
    t = fv;
    if (agent)
        *fv++ = CS_REMOTE_OPEN_AGENT;
    if (state->flags & CS_ADDR_LOCAL)
        *fv++ = CS_REMOTE_OPEN_LOCAL;
    if (state->flags & CS_ADDR_NOW)
        *fv++ = CS_REMOTE_OPEN_NOW;
    if (state->flags & CS_ADDR_SHARE)
        *fv++ = CS_REMOTE_OPEN_SHARE;
    if (state->flags & CS_ADDR_TEST)
        *fv++ = CS_REMOTE_OPEN_TEST;
    if (state->flags & CS_ADDR_TRUST)
        *fv++ = CS_REMOTE_OPEN_TRUST;
    if (fv == t)
        *fv++ = CS_REMOTE_OPEN_READ;
    *fv = 0;
}

/*
 * initiate service named by path on state->host w/state->flags
 * service is modified in place
 * 0 returned on success
 */

static int
initiate(register Cs_t* state, char* user, char* path, char* service, char* name)
{
    register char*  s;
    char*       on;
    char*       local;
    Sfio_t*     sp;
    Sfio_t*     np;
    int     n;
    char*       av[REMOTE_ARGC];
    char        buf[PATH_MAX / 4];

    local = csname(state, 0);
    s = service + strlen(service);
    *s++ = '/';
    if (!(state->flags & CS_ADDR_SHARE))
    {
        sfsprintf(buf, sizeof(buf), "%s\n", state->host);
        if (!(sp = tokline(buf, SF_STRING, NiL)))
            return -1;
    }
    else if (state->flags & CS_ADDR_LOCAL)
    {
        sfsprintf(buf, sizeof(buf), "%s\n", CS_HOST_LOCAL);
        if (!(sp = tokline(buf, SF_STRING, NiL)))
            return -1;
    }
    else
    {
        strcpy(s, CS_SVC_HOSTS);
        if (!(sp = tokline(service, SF_READ, NiL)))
        {
            if (streq(state->host, CS_HOST_SHARE))
                sfsprintf(buf, sizeof(buf), "%s\n%s\n", CS_HOST_SHARE, CS_HOST_LOCAL);
            else
                sfsprintf(buf, sizeof(buf), "%s\n%s\n%s\n", state->host, CS_HOST_SHARE, CS_HOST_LOCAL);
            if (!(sp = tokline(buf, SF_STRING, NiL)))
                return -1;
        }
    }
    sfsprintf(s, PATH_MAX - (s - service) - 1, "%s%s", name, CS_SVC_SUFFIX);
    while (s = sfgetr(sp, '\n', 1))
        if (tokscan(s, NiL, " %s ", &on) == 1)
        {
            if (streq(on, CS_HOST_LOCAL) || streq(on, local))
            {
                sfclose(sp);
                av[0] = service;
                av[1] = path;
                av[2] = 0;
                return procclose(procopen(av[0], av, NiL, NiL, PROC_PRIVELEGED|PROC_ZOMBIE)) < 0 ? -1 : 0;
            }
            else if (!streq(on, CS_HOST_SHARE))
            {
                Proc_t*     proc;
                time_t      otime;
                struct stat st;
                char        fv[REMOTE_FLAGC];
                long        ov[3];

                remote(state, on, user, path, 0, av, fv);
                otime = lstat(state->mount, &st) ? 0 : st.st_ctime;
                n = open("/dev/null", O_RDWR);
                ov[0] = PROC_FD_DUP(n, 0, 0);
                ov[1] = PROC_FD_DUP(n, 1, PROC_FD_PARENT|PROC_FD_CHILD);
                ov[2] = 0;
                if (proc = procopen(av[0], av, NiL, ov, PROC_PRIVELEGED|PROC_ZOMBIE))
                {
                    n = 1;
                    for (;;)
                    {
                        if (!lstat(state->mount, &st) && st.st_ctime != otime)
                        {
                            if (!procclose(proc))
                            {
                                sfclose(sp);
                                return 0;
                            }
                            break;
                        }

                        /*
                         * sleep() and MNT_TMP
                         * hack around remote
                         * fs cache delays
                         */

                        if (n >= CS_REMOTE_DELAY)
                        {
                            procclose(proc);
                            break;
                        }
                        if (n == 1)
                        {
                            *state->control = CS_MNT_TMP;
                            if (remove(state->mount))
                            {
                                close(open(state->mount, O_WRONLY|O_CREAT|O_TRUNC, 0));
                                remove(state->mount);
                            }
                            *state->control = CS_MNT_STREAM;
                        }
                        sleep(n);
                        n <<= 1;
                    }
                }
            }
            else if (!sfstacked(sp) && (np = csinfo(state, on, NiL)))
                sfstack(sp, np);
        }
    sfclose(sp);
    return -1;
}

/*
 * recursive csopen(state,path,CS_OPEN_TEST)
 * previous side effects preserved
 */

static int
reopen(register Cs_t* state, char* path)
{
    int     ret;
    Cs_t        tmp;

    static int  level;

    if (level >= 8)
        return -1;
    tmp = *state;
    level++;
    ret = csopen(&tmp, path, CS_OPEN_TEST);
    level--;
    state->addr = tmp.addr;
    state->port = tmp.port;
    return ret;
}

/*
 * use remote agent to initiate and authenticate service on path
 */

static int
agent(register Cs_t* state, const char* host, const char* user, const char* path)
{
    register int    n;
    register int    m;
    register char*  s;
    Proc_t*     proc;
    int     fd = -1;
    char*       av[REMOTE_ARGC];
    char        fv[REMOTE_FLAGC];
    char        buf[PATH_MAX / 4];
    char        num[64];
    char        tmp[64];

    remote(state, host, user, path, 1, av, fv);
    if (!(proc = procopen(av[0], av, NiL, NiL, PROC_READ|PROC_WRITE|PROC_PRIVELEGED)))
        goto sorry;
    if ((m = csread(state, proc->rfd, buf, sizeof(buf), CS_LINE)) <= 1)
        goto sorry;
    buf[--m] = 0;
    if (buf[--m] == 'A')
        buf[--m] = 0;
    else
        m = 0;
    if ((fd = reopen(state, buf)) < 0)
        goto sorry;
    if (m)
    {
        if ((m = csread(state, proc->rfd, buf, sizeof(buf), CS_LINE)) <= 1)
            goto sorry;
        if (cswrite(state, fd, buf, m) != m)
            goto sorry;
        if ((n = csread(state, fd, num, sizeof(num), CS_LINE)) <= 0)
            goto sorry;
        if (*num != '\n')
        {
            buf[m - 1] = 0;
            num[n - 1] = 0;
            n = sfsprintf(tmp, sizeof(tmp), "%s %s\n", num, (s = strchr(buf, ' ')) ? (s + 1) : buf);
            if (cswrite(state, proc->wfd, tmp, n) != n)
                goto sorry;
            if ((m = csread(state, proc->rfd, buf, sizeof(buf), CS_LINE)) <= 0)
                goto sorry;
            if (cswrite(state, fd, buf, m) != m)
                goto sorry;
            if (csread(state, fd, num, 1, CS_LINE) != 1)
                goto sorry;
            if (cswrite(state, proc->wfd, num, 1) != 1)
                goto sorry;
        }
    }
    procclose(proc);
    return fd;
 sorry:
    if (fd >= 0)
        close(fd);
    if (proc)
        procclose(proc);
    errno = EACCES;
    return -1;
}

/*
 * csattach() helper
 */

static int
doattach(register Cs_t* state, const char* path, int op, int mode, char* user, char* opath, char* tmp, char* serv, char*b)
{
    register int    n;
    int     fd;
    char*       s;

#if CS_LIB_STREAM || CS_LIB_V10

    int     fds[2];
    struct stat st;

    if (op & CS_OPEN_CREATE)
    {
        n = errno;
        if (chmod(path, mode))
        {
            remove(path);
            if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) < 0)
            {
                messagef((state->id, NiL, -1, "open: %s: %s: creat %o error", state->path, path, mode));
                return -1;
            }
            close(fd);
            chmod(path, mode);
        }
        errno = n;
        if (pipe(fds))
        {
            messagef((state->id, NiL, -1, "open: %s: pipe error", state->path, path));
            return -1;
        }

#if CS_LIB_V10

        if ((n = ioctl(fds[1], FIOPUSHLD, &conn_ld)) || fmount(3, fds[1], path, 0))

#else

        if ((n = ioctl(fds[1], I_PUSH, "connld")) || fattach(fds[1], path))

#endif

        {
            messagef((state->id, NiL, -1, "open: %s: %s: %s error", state->path, path, n ? "connld" : "fattach"));
            close(fds[0]);
            close(fds[1]);
            errno = ENXIO;
            return -1;
        }
        close(fds[1]);
        fd = fds[0];
    }
    else
        for (;;)
        {
            if ((fd = open(path, O_RDWR)) >= 0)
            {
                if (!fstat(fd, &st) && !S_ISREG(st.st_mode))
                    break;
                close(fd);
                remove(path);
            }
            else if ((op & CS_OPEN_TEST) || errno == EACCES)
            {
                messagef((state->id, NiL, -1, "open: %s: %s: open error", state->path, path));
                return -1;
            }
            if (initiate(state, user, opath, tmp, serv))
            {
                messagef((state->id, NiL, -1, "open: %s: %s: service initiate error", state->path, path));
                return -1;
            }
            op = CS_OPEN_TEST;
        }

#else

#if CS_LIB_SOCKET_UN

    int         pid;
    int         namlen;
    char            c;
    struct sockaddr_un  nam;

    messagef((state->id, NiL, -8, "%s:%d state.path=`%s' state.mount=`%s' path=`%s' opath=`%s' user=`%s' serv=`%s'", __FILE__, __LINE__, state->path, state->mount, path, opath, user, serv));
    nam.sun_family = AF_UNIX;
    strcpy(nam.sun_path, path);
    namlen = sizeof(nam.sun_family) + strlen(path) + 1;
    for (n = 0;; n++)
    {
        if (n >= 10)
        {
            errno = ENXIO;
        badcon:
            close(fd);
            return -1;
        }
        if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
        {
            messagef((state->id, NiL, -1, "open: %s: %s: AF_UNIX socket error", state->path, path));
            return -1;
        }
        if (!connect(fd, (struct sockaddr*)&nam, namlen))
        {
            if (op & CS_OPEN_CREATE)
            {
                errno = EEXIST;
                goto badcon;
            }
#if CS_LIB_SOCKET_RIGHTS
            if (read(fd, &c, 1) == 1 && !cssend(state, fd, NiL, 0))
                break;
#else
            break;
#endif
        }
        else
        {
            messagef((state->id, NiL, -1, "open: %s: %s: connect error", state->path, path));
            if (errno == EACCES)
                goto badcon;
            else if (errno == EADDRNOTAVAIL || errno == ECONNREFUSED)
            {
                c = 0;
                for (;;)
                {
                    *b = CS_MNT_PROCESS;
                    pid = pathgetlink(path, state->temp, sizeof(state->temp));
                    *b = CS_MNT_STREAM;
                    if (pid > 0 || ++c >= 5)
                        break;
                    sleep(1);
                }
                if (pid > 0 && (s = strrchr(state->temp, '/')) && (pid = strtol(s + 1, NiL, 0)) > 0)
                {
                    if (!kill(pid, 0) || errno != ESRCH)
                    {
                        if (op & CS_OPEN_CREATE)
                        {
                            errno = EEXIST;
                            goto badcon;
                        }
                        close(fd);
                        if (n)
                            sleep(1);
                        continue;
                    }
                    *b = CS_MNT_PROCESS;
                    remove(path);
                    *b = CS_MNT_STREAM;
                }
            }
        }
        close(fd);
        errno = ENOENT;
        if (op & CS_OPEN_CREATE)
        {
            if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
            {
                messagef((state->id, NiL, -1, "open: %s: %s: AF_UNIX socket error", state->path, path));
                return -1;
            }
            if (!bind(fd, (struct sockaddr*)&nam, namlen))
            {
                chmod(path, mode);
                if (listen(fd, 32))
                {
                    messagef((state->id, NiL, -1, "open: %s: %s: listen error", state->path, path));
                    n = errno;
                    remove(path);
                    errno = n;
                    goto badcon;
                }
                break;
            }
            else
                messagef((state->id, NiL, -1, "open: %s: %s: bind error", state->path, path));
            if (errno != EADDRINUSE || n && remove(path) && errno != ENOENT)
                goto badcon;
            close(fd);
        }
        else if (op & CS_OPEN_TEST)
            return -1;
        else if (!n && initiate(state, user, opath, tmp, serv))
        {
            messagef((state->id, NiL, -1, "open: %s: %s: service initiate error", state->path, path));
            return -1;
        }
        else
            sleep(2);
    }

#else

    errno = (op & CS_OPEN_CREATE) ? ENXIO : ENOENT;
    messagef((state->id, NiL, -1, "open: %s: %s: not supported", state->path, path));
    fd = -1;

#endif

#endif

#if CS_LIB_SOCKET_UN || CS_LIB_STREAM || CS_LIB_V10

    touch(path, (time_t)0, (time_t)0, 0);
    strcpy(state->path, path);

#endif

    return fd;
}

/*
 * return connect stream to fdp path
 * if (op & CS_) then path is created
 * and server connect stream is returned
 * otherwise client connect stream returned
 */

int
csattach(register Cs_t* state, const char* path, int op, int mode)
{
    return doattach(state, path, op, 0, 0, 0, 0, 0, 0);
}

int
_cs_attach(const char* path, int op, int mode)
{
    return csattach(&cs, path, op, mode);
}

/*
 * access/open/create service on path
 */

int
csopen(register Cs_t* state, const char* apath, int op)
{
    register char*  path = (char*)apath;
    register char*  b;
    register char*  s;
    register int    n;
    int     fd;
    char*       t;
    char*       u;
    char*       type;
    char*       endtype;
    char*       host;
    char*       endhost;
    char*       serv;
    char*       endserv;
    char*       qual;
    char*       endqual;
    char*       opath;
    char*       user = 0;
    char*       group = 0;
    char*       trust = 0;
    char*       arg = 0;
    int     nfd = -1;
    int     uid = -1;
    int     gid = -1;
    int     sid = -1;
    int     auth = 1;
    int     mode;
    unsigned long   addr;
    unsigned long   port = 0;
    struct stat st;
    gid_t       groups[NGROUPS_MAX + 1];
    char        buf[PATH_MAX];
    char        tmp[PATH_MAX];

    if (!path)
    {
        errno = EFAULT;
        return -1;
    }
    csprotect(&cs);
    if (op < 0)
        op = CS_OPEN_TEST;
    messagef((state->id, NiL, -8, "open(%s,%o) call", path, op));

    /*
     * blast out the parts
     */

    opath = path;
    if (pathgetlink(path, buf, sizeof(buf)) <= 0)
    {
        if (strlen(path) >= sizeof(buf))
            return -1;
        strcpy(buf, path);
    }
    else if ((state->flags & CS_ADDR_LOCAL) && (s = strrchr(buf, '/')))
    {
        /*
         * dynamic ip assignment can change the addr
         * underfoot in some implementations so we
         * double check the local ip here
         */

        strcpy(tmp, buf);
        if (tokscan(tmp, NiL, "/dev/%s/%s/%s", &type, NiL, &serv) == 3)
            sfsprintf(buf, sizeof(buf), "/dev/%s/%s/%s", type, csntoa(state, 0), serv);
    }
    path = buf;
    pathcanon(path, 0, 0);
    errno = ENOENT;
    strcpy(state->path, path);
    b = path;
    if ((*b++ != '/') || !(s = strchr(b, '/')))
        return -1;
    *s++ = 0;
    if (!streq(b, "dev"))
        return -1;
    if (b = strchr(s, '/'))
        *b++ = 0;
    if (streq(s, "fdp"))
    {
#if !( CS_LIB_SOCKET_UN || CS_LIB_STREAM || CS_LIB_V10 )
        if (access(CS_PROC_FD_TST, F_OK))
        {
            errno = ENODEV;
            messagef((state->id, NiL, -1, "open: %s: %s: not supported", state->path, s));
            return -1;
        }
#endif
    }
    else if (!streq(s, "tcp") && !streq(s, "udp"))
    {
        messagef((state->id, NiL, -1, "open: %s: %s: invalid type", state->path, s));
        return -1;
    }
#if !( CS_LIB_SOCKET || CS_LIB_STREAM || CS_LIB_V10 )
    else
    {
        errno = ENODEV;
        messagef((state->id, NiL, -1, "open: %s: %s: not supported", state->path, s));
        return -1;
    }
#endif
    type = s;
    qual = state->qual;
    if (!b)
        host = serv = 0;
    else
    {
        host = b;
        if (!(s = strchr(b, '/')))
            serv = 0;
        else
        {
            *s++ = 0;
            serv = s;

            /*
             * grab the next fd to preserve open semantics
             */

            for (n = 0; n < 10; n++)
                if ((nfd = dup(n)) >= 0)
                    break;

            /*
             * get qual, perm and arg
             */

            mode = S_IRWXU|S_IRWXG|S_IRWXO;
            if (b = strchr(s, '/'))
            {
                *b++ = 0;
                do
                {
                    if (*b == '#')
                    {
                        arg = b + 1;
                        break;
                    }
                    if (u = strchr(b, '/'))
                        *u++ = 0;
                    if (s = strchr(b, '='))
                        *s++ = 0;
                    for (n = 0, t = b; *t; n = HASHKEYPART(n, *t++));
                    switch (n)
                    {
                    case HASHKEY5('g','r','o','u','p'):
                        group = s ? s : "";
                        break;
                    case HASHKEY5('l','o','c','a','l'):
                        op |= CS_OPEN_LOCAL;
                        break;
                    case HASHKEY3('n','o','w'):
                        op |= CS_OPEN_NOW;
                        break;
                    case HASHKEY5('o','t','h','e','r'):
                        auth = 0;
                        break;
                    case HASHKEY6('r','e','m','o','t','e'):
                        op |= CS_OPEN_REMOTE;
                        break;
                    case HASHKEY5('s','h','a','r','e'):
                        op |= CS_OPEN_SHARE;
                        break;
                    case HASHKEY5('s','l','a','v','e'):
                        op |= CS_OPEN_SLAVE;
                        break;
                    case HASHKEY4('t','e','s','t'):
                        op |= CS_OPEN_TEST;
                        break;
                    case HASHKEY5('t','r','u','s','t'):
                        op |= CS_OPEN_TRUST;
                        trust = s;
                        break;
                    case HASHKEY4('u','s','e','r'):
                        user = s ? s : "";
                        break;
                    default:
                        qual += sfsprintf(qual, sizeof(state->qual) - (qual - state->qual) - 1, "%s%s", qual == state->qual ? "" : "-", b);
                        if (s)
                            *(s - 1) = '=';
                        break;
                    }
                } while (b = u);
            }
        }
    }
    if (*type != 't')
        auth = 0;
    strncpy(state->type, type, sizeof(state->type) - 1);
    qual = (qual == state->qual) ? (char*)0 : state->qual;
    messagef((state->id, NiL, -8, "open: type=%s host=%s serv=%s qual=%s", type, host, serv, qual));
    if (host)
    {
        /*
         * validate host
         */

        if (!(state->addr = addr = csaddr(state, host)))
        {
            if (serv && !(op & CS_OPEN_CREATE) && *type == 't' && (port = csport(state, type, serv)) >= CS_PORT_MIN && port <= CS_PORT_MAX)
            {
                /*
                 * attempt proxy connection
                 */

                if (nfd >= 0)
                {
                    close(nfd);
                    nfd = -1;
                }
                if ((fd = state->proxy.addr ? csbind(state, type, state->proxy.addr, state->proxy.port, 0L) : reopen(state, csvar(state, CS_VAR_PROXY, 0))) >= 0)
                {
                    state->proxy.addr = state->addr;
                    state->proxy.port = state->port;
                    n = sfsprintf(tmp, sizeof(tmp), "\n%s!%s!%d\n\n%s\n%s\n0\n-1\n-1\n", type, host, port, csname(state, 0), error_info.id ? error_info.id : state->id);
                    if (cswrite(state, fd, tmp, n) == n && (n = csread(state, fd, tmp, sizeof(tmp), CS_LINE)) >= 2)
                    {
                        if (tmp[0] == '0' && tmp[1] == '\n')
                            return fd;
                        if (error_info.trace <= -4 && n > 2)
                        {
                            s = tmp;
                            s[n - 1] = 0;
                            while (*s && *s++ != '\n');
                            messagef((state->id, NiL, -4, "%s error message `%s'", csvar(state, CS_VAR_PROXY, 0), s));
                        }
                    }
                    close(fd);
                }
            }
#ifdef EADDRNOTAVAIL
            errno = EADDRNOTAVAIL;
#else
            errno = ENOENT;
#endif
            goto bad;
        }
        if (op & CS_OPEN_LOCAL)
        {
            state->flags |= CS_ADDR_LOCAL;
            state->flags &= ~CS_ADDR_REMOTE;
        }
        if (op & CS_OPEN_NOW)
            state->flags |= CS_ADDR_NOW;
        if ((op & (CS_OPEN_AGENT|CS_OPEN_REMOTE)) == CS_OPEN_REMOTE)
        {
            state->flags |= CS_ADDR_REMOTE;
            state->flags &= ~CS_ADDR_LOCAL;
        }
        if (op & CS_OPEN_SHARE)
            state->flags |= CS_ADDR_SHARE;
        if (op & CS_OPEN_SLAVE)
            state->flags |= CS_DAEMON_SLAVE;
        if (op & CS_OPEN_TEST)
            state->flags |= CS_ADDR_TEST;
        if (op & CS_OPEN_TRUST)
            state->flags |= CS_ADDR_TRUST;
        if ((state->flags & CS_ADDR_REMOTE) && (!serv || !strneq(serv, CS_SVC_INET, sizeof(CS_SVC_INET) - 1) && (strtol(serv, &t, 0), *t)))
            return agent(state, state->host, state->user, state->path);
        if (s = user)
        {
            n = geteuid();
            if (*s)
            {
                if ((uid = struid(s)) < 0)
                {
                    uid = strtol(s, &t, 0);
                    if (*t)
                    {
                        errno = EACCES;
                        goto bad;
                    }
                }
                if (n && uid != n)
                {
                    errno = EACCES;
                    goto bad;
                }
            }
            else
                uid = n;
            mode &= ~(S_IRWXG|S_IRWXO);
        }
        if (s = group)
        {
            n = getegid();
            if (*s)
            {
                if ((gid = strgid(s)) < 0)
                {
                    gid = strtol(s, &t, 0);
                    if (*t)
                    {
                        errno = EACCES;
                        goto bad;
                    }
                }
                if (geteuid() && gid != n)
                {
                    for (n = getgroups(elementsof(groups), groups); n >= 0; n--)
                        if (gid == groups[n])
                            break;
                    if (n < 0)
                    {
                        errno = EACCES;
                        goto bad;
                    }
                }
            }
            else
                gid = n;
            mode &= ~S_IRWXO;
        }
        if (s = trust)
        {
            if (!*s)
                sid = geteuid();
            else if ((sid = struid(s)) < 0)
            {
                sid = strtol(s, &t, 0);
                if (*t)
                {
                    errno = EACCES;
                    goto bad;
                }
            }
        }
        if (state->flags & CS_ADDR_SHARE)
            host = CS_HOST_SHARE;
        else
        {
            host = state->host;
            if (!(state->flags & CS_ADDR_LOCAL))
            {
                if (*type == 'f')
                {
                    errno = ENODEV;
                    goto bad;
                }
                if (op & CS_OPEN_CREATE)
                {
                    errno = EROFS;
                    goto bad;
                }
            }
            if (serv && !qual && *type != 'f' && (port = csport(state, type, serv)) != CS_PORT_INVALID)
            {
                if (op & CS_OPEN_CREATE)
                    addr = 0;
                else if (port == CS_PORT_RESERVED || port == CS_PORT_NORMAL)
                    goto bad;
                if (nfd >= 0)
                {
                    close(nfd);
                    nfd = -1;
                }
                state->control = 0;
                if ((fd = csbind(state, type, addr, port, 0L)) >= 0)
                {
                    if (mode != (S_IRWXU|S_IRWXG|S_IRWXO) && csauth(state, fd, NiL, NiL))
                    {
                        close(fd);
                        return -1;
                    }
                    return fd;
                }
            }
        }
    }

    /*
     * get the mount dir prefix
     */

    if (opath == (b = path = state->mount))
    {
#ifdef ELOOP
        errno = ELOOP;
#else
        errno = EINVAL;
#endif
        goto bad;
    }
    if (*type == 'f')
    {
        if (host && !(state->flags & CS_ADDR_LOCAL))
        {
            errno = ENODEV;
            goto bad;
        }
        b += sfsprintf(b, sizeof(state->mount) - (b - path), "%s", csvar(state, CS_VAR_LOCAL, 0));
        if ((op & CS_OPEN_CREATE) && eaccess(path, X_OK) && (mkdir(path, S_IRWXU|S_IRWXG|S_IRWXO) || chmod(path, S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO)))
            goto bad;
    }
    else
    {
        if (op & CS_OPEN_TRUST)
        {
            if (!pathaccess(csvar(state, CS_VAR_TRUST, 1), csvar(state, CS_VAR_SHARE, 1), NiL, PATH_EXECUTE, b, sizeof(state->mount) - (b - state->mount)))
                goto bad;
        }
        else if (!pathpath(csvar(state, CS_VAR_SHARE, 0), "", PATH_EXECUTE, b, sizeof(state->mount) - (b - state->mount)))
            goto bad;
        b += strlen(b);
    }

    /*
     * add the type
     */

    b += sfsprintf(b, sizeof(state->mount) - (b - path), "/%s", type);
    if (!host)
    {
        *(state->control = b + 1) = 0;
        if (nfd >= 0)
            close(nfd);
        if ((fd = open(path, O_RDONLY)) < 0)
        {
            mkmount(state, S_IRWXU|S_IRWXG|S_IRWXO, -1, -1, NiL, NiL, NiL);
            fd = open(path, O_RDONLY);
        }
        if (fd < 0)
            messagef((state->id, NiL, -1, "open: %s: %s: open error", state->path, path));
        return fd;
    }
    endtype = b;

    /*
     * add the host
     */

    if (strlen(host) <= CS_MNT_MAX)
        b += sfsprintf(b, sizeof(state->mount) - (b - path), "/%s", host);
    else
    {
        s = csntoa(state, addr);
        if (strlen(s) <= CS_MNT_MAX)
            b += sfsprintf(b, sizeof(state->mount) - (b - path), "/%s", s);
        else
        {
            unsigned char*  a = (unsigned char*)&addr;

            b += sfsprintf(b, sizeof(state->mount) - (b - path), "/0x%X.%X.%X.%X", a[0], a[1], a[2], a[3]);
        }
    }
    messagef((state->id, NiL, -8, "%s:%d host=`%s' path=`%s'", __FILE__, __LINE__, host, path));
    if (!serv)
    {
        *(state->control = b + 1) = 0;
        if (nfd >= 0)
            close(nfd);
        if ((fd = open(path, O_RDONLY)) < 0)
            messagef((state->id, NiL, -1, "open: %s: %s: open error", state->path, path));
        return fd;
    }
    endhost = b;

    /*
     * add the service
     */

    sfsprintf(b, sizeof(state->mount) - (b - path), "%s/%s/%s/%s%s", CS_SVC_DIR, type, serv, serv, CS_SVC_SUFFIX);
    if (!pathpath(b, "", PATH_ABSOLUTE|PATH_EXECUTE, tmp, sizeof(tmp)) || stat(tmp, &st))
        op |= CS_OPEN_TEST;
    else
    {
        *strrchr(tmp, '/') = 0;
        if (!(op & CS_OPEN_TRUST))
            sid = st.st_uid;
        if (!st.st_size)
            op |= CS_OPEN_TEST;
    }
    b += sfsprintf(b, sizeof(state->mount) - (b - path), "/%s", serv);
    endserv = b;

    /*
     * add the qualifier and perm
     */

    if (sid >= 0)
        b += sfsprintf(b, sizeof(state->mount) - (b - path), "/%d-", sid);
    else
        b += sfsprintf(b, sizeof(state->mount) - (b - path), "/-");
    if (uid >= 0)
        b += sfsprintf(b, sizeof(state->mount) - (b - path), "%d-", uid);
    else if (gid >= 0)
        b += sfsprintf(b, sizeof(state->mount) - (b - path), "-%d", gid);
    else
        b += sfsprintf(b, sizeof(state->mount) - (b - path), "-");
#if limit_qualifier_length
    endqual = endserv + CS_MNT_MAX + 1;
#else
    endqual = state->mount + sizeof(state->mount) - 1;
#endif
    if (qual)
    {
        if (b < endqual)
            *b++ = '-';
        while (b < endqual && *qual)
            *b++ = *qual++;
    }
    if (*type == 't' && !auth)
    {
        if (b >= endqual)
            b--;
        *b++ = CS_MNT_OTHER;
    }

    /*
     * add in the connect stream control
     */

    *b++ = '/';
    *b = CS_MNT_STREAM;
    strcpy(b + 1, CS_MNT_TAIL);
    messagef((state->id, NiL, -8, "%s:%d %s", __FILE__, __LINE__, state->mount));
    state->control = b;

    /*
     * create the mount subdirs if necessary
     */

    if ((op & CS_OPEN_CREATE) && mkmount(state, mode, uid, gid, endserv, endhost, endtype))
        goto bad;
    mode &= S_IRWXU|S_IRWXG|S_IRWXO;
    if (nfd >= 0)
    {
        close(nfd);
        nfd = -1;
    }
    if (op & CS_OPEN_MOUNT)
    {
        messagef((state->id, NiL, -1, "open(%s,%o) = %d, mount = %s", state->path, op, state->mount));
        return 0;
    }
    if (*type == 'f')
    {
        /*
         * {fdp}
         */

        if ((fd = doattach(state, path, op, mode, user, opath, tmp, serv, b)) < 0)
            return -1;
    }
    else
    {
        /*
         * {tcp,udp}
         */

        messagef((state->id, NiL, -8, "%s:%d %s", __FILE__, __LINE__, state->mount));
        if ((fd = reopen(state, path)) < 0)
        {
            /*
             * check for old single char cs mount
             */

            *(state->control + 1) = 0;
            if ((fd = reopen(state, path)) < 0)
                messagef((state->id, NiL, -1, "open: %s: %s: reopen error", state->path, path));
            *(state->control + 1) = CS_MNT_TAIL[0];
        }
        if (op & CS_OPEN_CREATE)
        {
            if (fd >= 0)
            {
                close(fd);
                errno = EEXIST;
                return -1;
            }
            if (errno != ENOENT && errno != ENOTDIR)
                return -1;
            sigcritical(1);
            *state->control = CS_MNT_LOCK;
            if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0)) < 0)
            {
                if (stat(path, &st))
                {
                    messagef((state->id, NiL, -1, "open: %s: %s: creat error", state->path, path));
                    goto unblock;
                }
                if ((CSTIME() - (unsigned long)st.st_ctime) < 2 * 60)
                {
                    errno = EEXIST;
                    messagef((state->id, NiL, -1, "open: %s: %s: another server won the race", state->path, path));
                    goto unblock;
                }
                if (remove(path))
                {
                    messagef((state->id, NiL, -1, "open: %s: %s: remove error", state->path, path));
                    goto unblock;
                }
                if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0)) < 0)
                {
                    messagef((state->id, NiL, -1, "open: %s: %s: creat error", state->path, path));
                    goto unblock;
                }
            }
            close(fd);
            if (!port && (n = strtol(serv, &t, 0)) && t > serv && !*t)
                port = n;
            else if (geteuid())
                port = CS_NORMAL;
            else
                port = CS_RESERVED;
            if ((fd = csbind(state, type, 0L, port, 0L)) >= 0)
            {
                *state->control = CS_MNT_STREAM;
                remove(path);
                if (pathsetlink(cspath(state, fd, 0), path))
                {
                    messagef((state->id, NiL, -1, "open: %s: %s: link error", cspath(state, fd, 0), path));
                    close(fd);
                    fd = -1;
                }
            }
        unblock:
            *state->control = CS_MNT_LOCK;
            remove(path);
            sigcritical(0);
            *state->control = CS_MNT_STREAM;
            if (fd < 0)
                return -1;
        }
        else if (fd < 0 && ((op & CS_OPEN_TEST) || initiate(state, user, opath, tmp, serv) || (fd = reopen(state, path)) < 0))
        {
            messagef((state->id, NiL, -1, "open: %s: %s: reopen/initiate error", state->path, path));
            return -1;
        }
        else if (!(op & CS_OPEN_AGENT))
        {
            *state->control = CS_MNT_AUTH;
            n = csauth(state, fd, path, arg);
            *state->control = CS_MNT_STREAM;
            if (n)
            {
                close(fd);
                messagef((state->id, NiL, -1, "open: %s: %s: authentication error", state->path, path));
                return -1;
            }
        }
    }

    /*
     * fd is open at this point
     * make sure its not a bogus mount
     */

    if (mode != (S_IRWXU|S_IRWXG|S_IRWXO))
    {
        *state->control = 0;
        n = stat(path, &st);
        *state->control = CS_MNT_STREAM;
        if (n)
        {
            messagef((state->id, NiL, -1, "open: %s: %s: stat error", state->path, path));
            close(fd);
            return -1;
        }
        if (uid >= 0 && st.st_uid != uid || gid >= 0 && st.st_gid != gid)
        {
            close(fd);
            errno = EPERM;
            messagef((state->id, NiL, -1, "open: %s: %s: uid/gid error", state->path, path));
            return -1;
        }
    }
    return fd;
 bad:
    if (nfd >= 0)
        close(nfd);
    return -1;
}

int
_cs_open(const char* apath, int op)
{
    return csopen(&cs, apath, op);
}