Annotation of libelwix/src/pio.c, revision 1.2

1.2     ! misho       1: /*************************************************************************
        !             2: * (C) 2013 AITNET ltd - Sofia/Bulgaria - <misho@aitnet.org>
        !             3: *  by Michael Pounov <misho@elwix.org>
        !             4: *
        !             5: * $Author: misho $
        !             6: * $Id: pio.c,v 1.1.2.7 2013/12/06 00:50:16 misho Exp $
        !             7: *
        !             8: **************************************************************************
        !             9: The ELWIX and AITNET software is distributed under the following
        !            10: terms:
        !            11: 
        !            12: All of the documentation and software included in the ELWIX and AITNET
        !            13: Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>
        !            14: 
        !            15: Copyright 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
        !            16:        by Michael Pounov <misho@elwix.org>.  All rights reserved.
        !            17: 
        !            18: Redistribution and use in source and binary forms, with or without
        !            19: modification, are permitted provided that the following conditions
        !            20: are met:
        !            21: 1. Redistributions of source code must retain the above copyright
        !            22:    notice, this list of conditions and the following disclaimer.
        !            23: 2. Redistributions in binary form must reproduce the above copyright
        !            24:    notice, this list of conditions and the following disclaimer in the
        !            25:    documentation and/or other materials provided with the distribution.
        !            26: 3. All advertising materials mentioning features or use of this software
        !            27:    must display the following acknowledgement:
        !            28: This product includes software developed by Michael Pounov <misho@elwix.org>
        !            29: ELWIX - Embedded LightWeight unIX and its contributors.
        !            30: 4. Neither the name of AITNET nor the names of its contributors
        !            31:    may be used to endorse or promote products derived from this software
        !            32:    without specific prior written permission.
        !            33: 
        !            34: THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``AS IS'' AND
        !            35: ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
        !            36: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
        !            37: ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
        !            38: FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
        !            39: DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
        !            40: OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
        !            41: HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
        !            42: LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
        !            43: OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
        !            44: SUCH DAMAGE.
        !            45: */
        !            46: #include "global.h"
        !            47: 
        !            48: 
        !            49: extern char **environ;
        !            50: 
        !            51: pio_pid_t pio_pidlist = SLIST_HEAD_INITIALIZER(pio_pidlist);
        !            52: static pthread_mutex_t pidlist_mutex = PTHREAD_MUTEX_INITIALIZER;
        !            53: 
        !            54: #define        THREAD_LOCK()   if (__isthreaded) pthread_mutex_lock(&pidlist_mutex)
        !            55: #define        THREAD_UNLOCK() if (__isthreaded) pthread_mutex_unlock(&pidlist_mutex)
        !            56: 
        !            57: 
        !            58: /*
        !            59:  * e_popen() - ELWIX replacement of standard popen
        !            60:  *
        !            61:  * @command = command
        !            62:  * @type = type
        !            63:  * @ppid = return pid of child program
        !            64:  * return: NULL error or !=NULL open program
        !            65:  */
        !            66: #ifdef POPEN_STREAM
        !            67: FILE *
        !            68: #else
        !            69: int
        !            70: #endif
        !            71: e_popen(const char *command, const char *type, pid_t *ppid)
        !            72: {
        !            73:        struct tagPIOPID *cur, *p;
        !            74:        int pdes[2], pid, twoway, cloexec;
        !            75:        char *argv[4];
        !            76: 
        !            77:        if (!command || !type)
        !            78: #ifdef POPEN_STREAM
        !            79:                return NULL;
        !            80: #else
        !            81:                return -1;
        !            82: #endif
        !            83: 
        !            84:        cloexec = strchr(type, 'e') != NULL;
        !            85:        /*
        !            86:         * Lite2 introduced two-way popen() pipes using _socketpair().
        !            87:         * FreeBSD's pipe() is bidirectional, so we use that.
        !            88:         */
        !            89:        if (strchr(type, '+')) {
        !            90:                twoway = 1;
        !            91:                type = "r+";
        !            92:        } else {
        !            93:                twoway = 0;
        !            94:                if ((*type != 'r' && *type != 'w') || 
        !            95:                                (type[1] && (type[1] != 'e' || type[2])))
        !            96: #ifdef POPEN_STREAM
        !            97:                        return NULL;
        !            98: #else
        !            99:                        return -1;
        !           100: #endif
        !           101:        }
        !           102:        if (socketpair(AF_UNIX, SOCK_STREAM | (cloexec ? O_CLOEXEC : 0), 
        !           103:                                0, pdes) < 0) {
        !           104:                LOGERR;
        !           105: #ifdef POPEN_STREAM
        !           106:                return NULL;
        !           107: #else
        !           108:                return -1;
        !           109: #endif
        !           110:        }
        !           111: 
        !           112:        if (!(cur = e_malloc(sizeof(struct tagPIOPID)))) {
        !           113:                close(pdes[0]);
        !           114:                close(pdes[1]);
        !           115: #ifdef POPEN_STREAM
        !           116:                return NULL;
        !           117: #else
        !           118:                return -1;
        !           119: #endif
        !           120:        }
        !           121: 
        !           122:        argv[0] = "sh";
        !           123:        argv[1] = "-c";
        !           124:        argv[2] = (char *) command;
        !           125:        argv[3] = NULL;
        !           126: 
        !           127:        THREAD_LOCK();
        !           128:        switch (pid = vfork()) {
        !           129:        case -1:                        /* Error. */
        !           130:                LOGERR;
        !           131:                THREAD_UNLOCK();
        !           132:                close(pdes[0]);
        !           133:                close(pdes[1]);
        !           134:                e_free(cur);
        !           135: #ifdef POPEN_STREAM
        !           136:                return NULL;
        !           137: #else
        !           138:                return -1;
        !           139: #endif
        !           140:                /* NOTREACHED */
        !           141:        case 0:                         /* Child. */
        !           142:                if (*type == 'r') {
        !           143:                        /*
        !           144:                         * The _dup2() to STDIN_FILENO is repeated to avoid
        !           145:                         * writing to pdes[1], which might corrupt the
        !           146:                         * parent's copy.  This isn't good enough in
        !           147:                         * general, since the _exit() is no return, so
        !           148:                         * the compiler is free to corrupt all the local
        !           149:                         * variables.
        !           150:                         */
        !           151:                        if (!cloexec)
        !           152:                                close(pdes[0]);
        !           153:                        if (pdes[1] != STDOUT_FILENO) {
        !           154:                                dup2(pdes[1], STDOUT_FILENO);
        !           155:                                if (!cloexec)
        !           156:                                        close(pdes[1]);
        !           157:                                if (twoway)
        !           158:                                        dup2(STDOUT_FILENO, STDIN_FILENO);
        !           159:                        } else if (twoway && (pdes[1] != STDIN_FILENO)) {
        !           160:                                dup2(pdes[1], STDIN_FILENO);
        !           161:                                if (cloexec)
        !           162:                                        fcntl(pdes[1], F_SETFD, 0);
        !           163:                        } else if (cloexec)
        !           164:                                fcntl(pdes[1], F_SETFD, 0);
        !           165:                } else {
        !           166:                        if (pdes[0] != STDIN_FILENO) {
        !           167:                                dup2(pdes[0], STDIN_FILENO);
        !           168:                                if (!cloexec)
        !           169:                                        close(pdes[0]);
        !           170:                        } else if (cloexec)
        !           171:                                fcntl(pdes[0], F_SETFD, 0);
        !           172:                        if (!cloexec)
        !           173:                                close(pdes[1]);
        !           174:                }
        !           175:                SLIST_FOREACH(p, &pio_pidlist, next)
        !           176: #ifdef POPEN_STREAM
        !           177:                        close(fileno(p->f.fp));
        !           178: #else
        !           179:                        close(p->f.fd);
        !           180: #endif
        !           181:                execve(_PATH_BSHELL, argv, environ);
        !           182:                _exit(127);
        !           183:                /* NOTREACHED */
        !           184:        default:
        !           185:                if (ppid)
        !           186:                        *ppid = pid;
        !           187:        }
        !           188:        THREAD_UNLOCK();
        !           189: 
        !           190:        /* Parent; assume fdopen can't fail. */
        !           191:        if (*type == 'r') {
        !           192: #ifdef POPEN_STREAM
        !           193:                cur->f.fp = fdopen(pdes[0], type);
        !           194: #else
        !           195:                cur->f.fd = pdes[0];
        !           196: #endif
        !           197:                close(pdes[1]);
        !           198:        } else {
        !           199: #ifdef POPEN_STREAM
        !           200:                cur->f.fp = fdopen(pdes[1], type);
        !           201: #else
        !           202:                cur->f.fd = pdes[1];
        !           203: #endif
        !           204:                close(pdes[0]);
        !           205:        }
        !           206: 
        !           207:        /* Link into list of file descriptors. */
        !           208:        cur->pid = pid;
        !           209:        THREAD_LOCK();
        !           210:        SLIST_INSERT_HEAD(&pio_pidlist, cur, next);
        !           211:        THREAD_UNLOCK();
        !           212: 
        !           213: #ifdef POPEN_STREAM
        !           214:        return cur->f.fp;
        !           215: #else
        !           216:        return cur->f.fd;
        !           217: #endif
        !           218: }
        !           219: 
        !           220: /*
        !           221:  * e_pclose() - ELWIX replacement of standard pclose
        !           222:  *
        !           223:  * @iop = popen handle
        !           224:  * return: -1 error or !=-1 pid status
        !           225:  */
        !           226: int
        !           227: #ifdef POPEN_STREAM
        !           228: e_pclose(FILE *iop)
        !           229: #else
        !           230: e_pclose(int iop)
        !           231: #endif
        !           232: {
        !           233:        struct tagPIOPID *cur, *last = NULL;
        !           234:        int pstat;
        !           235:        pid_t pid;
        !           236: 
        !           237:        if (!iop)
        !           238:                return -1;
        !           239: 
        !           240:        /*
        !           241:         * Find the appropriate file pointer and remove it from the list.
        !           242:         */
        !           243:        THREAD_LOCK();
        !           244:        SLIST_FOREACH(cur, &pio_pidlist, next) {
        !           245: #ifdef POPEN_STREAM
        !           246:                if (cur->f.fp == iop)
        !           247: #else
        !           248:                if (cur->f.fd == iop)
        !           249: #endif
        !           250:                        break;
        !           251:                last = cur;
        !           252:        }
        !           253:        if (!cur) {
        !           254:                THREAD_UNLOCK();
        !           255:                return (-1);
        !           256:        }
        !           257:        if (!last)
        !           258:                SLIST_REMOVE_HEAD(&pio_pidlist, next);
        !           259:        else
        !           260:                SLIST_REMOVE_AFTER(last, next);
        !           261:        THREAD_UNLOCK();
        !           262: 
        !           263: #ifdef POPEN_STREAM
        !           264:        fclose(iop);
        !           265: #else
        !           266:        close(iop);
        !           267: #endif
        !           268: 
        !           269:        do {
        !           270:                pid = wait4(cur->pid, &pstat, 0, NULL);
        !           271:        } while (pid == -1 && errno == EINTR);
        !           272: 
        !           273:        e_free(cur);
        !           274: 
        !           275:        return (pid == -1 ? -1 : pstat);
        !           276: }
        !           277: 
        !           278: /*
        !           279:  * pio_pgetpid() - Get tagPIOPID structure from file handle
        !           280:  *
        !           281:  * @iop = popen handle
        !           282:  * return: NULL error or !=NULL tagPIOPID structure
        !           283:  */
        !           284: struct tagPIOPID *
        !           285: #ifdef POPEN_STREAM
        !           286: pio_pgetpid(FILE *iop)
        !           287: #else
        !           288: pio_pgetpid(int iop)
        !           289: #endif
        !           290: {
        !           291:        struct tagPIOPID *p;
        !           292: 
        !           293:        if (!iop)
        !           294:                return NULL;
        !           295: 
        !           296:        THREAD_LOCK();
        !           297:        SLIST_FOREACH(p, &pio_pidlist, next)
        !           298: #ifdef POPEN_STREAM
        !           299:                if (p->f.fp == iop)
        !           300: #else
        !           301:                if (p->f.fd == iop)
        !           302: #endif
        !           303:                        break;
        !           304:        THREAD_UNLOCK();
        !           305: 
        !           306:        return p;
        !           307: }
        !           308: 
        !           309: /*
        !           310:  * pio_pchkpid() - Check exit status of child programs
        !           311:  *
        !           312:  * @pids = return tagPIOPID structures of exited programs, 
        !           313:  *             if !=NULL must call array_Destroy()
        !           314:  * return: -1 error or >-1 exited programs
        !           315:  */
        !           316: int
        !           317: pio_pchkpid(array_t ** __restrict pids)
        !           318: {
        !           319:        register int ret = 0;
        !           320:        struct tagPIOPID *p;
        !           321:        array_t *pa;
        !           322: 
        !           323:        if (pids) {
        !           324:                if (!(pa = array_Init(0)))
        !           325:                        return -1;
        !           326:                else
        !           327:                        *pids = pa;
        !           328:        }
        !           329: 
        !           330:        THREAD_LOCK();
        !           331:        SLIST_FOREACH(p, &pio_pidlist, next)
        !           332: #ifdef POPEN_STREAM
        !           333:                if (p->f.fp && waitpid(p->pid, &p->stat, WNOHANG) > 0) {
        !           334: #else
        !           335:                if (p->f.fd && waitpid(p->pid, &p->stat, WNOHANG) > 0) {
        !           336: #endif
        !           337:                        if (pids)
        !           338:                                array_Push(pa, p, 0);
        !           339:                        ret++;
        !           340:                }
        !           341:        THREAD_UNLOCK();
        !           342: 
        !           343:        return ret;
        !           344: }

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