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9da13f321c
Could still deadlock on the close(). A surrogate parent should be used to create the children...
82 lines
1.5 KiB
C
82 lines
1.5 KiB
C
/* fork.c - fork and exec a process, connecting stdin/out w/pipes */
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#include "portable.h"
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#include <stdio.h>
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#include <ac/string.h>
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#include <ac/socket.h>
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#include <ac/unistd.h>
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#include "slap.h"
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#include "shell.h"
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int
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forkandexec(
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char **args,
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FILE **rfp,
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FILE **wfp
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)
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{
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int p2c[2], c2p[2];
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int pid;
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if ( pipe( p2c ) != 0 || pipe( c2p ) != 0 ) {
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Debug( LDAP_DEBUG_ANY, "pipe failed\n", 0, 0, 0 );
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return( -1 );
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}
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/*
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* what we're trying to set up looks like this:
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* parent *wfp -> p2c[1] | p2c[0] -> stdin child
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* parent *rfp <- c2p[0] | c2p[1] <- stdout child
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*/
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#ifdef HAVE_THR
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switch ( (pid = fork1()) )
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#else
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switch ( (pid = fork()) )
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#endif
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{
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case 0: /* child */
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/*
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* child could deadlock here due to resources locked
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* by our parent
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*
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* If so, configure --without-threads or implement forking
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* via a surrogate parent.
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*/
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close( p2c[1] );
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close( c2p[0] );
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if ( dup2( p2c[0], 0 ) == -1 || dup2( c2p[1], 1 ) == -1 ) {
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Debug( LDAP_DEBUG_ANY, "dup2 failed\n", 0, 0, 0 );
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exit( -1 );
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}
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execv( args[0], args );
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Debug( LDAP_DEBUG_ANY, "execv failed\n", 0, 0, 0 );
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exit( -1 );
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case -1: /* trouble */
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Debug( LDAP_DEBUG_ANY, "fork failed\n", 0, 0, 0 );
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return( -1 );
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default: /* parent */
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close( p2c[0] );
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close( c2p[1] );
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break;
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}
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if ( (*rfp = fdopen( c2p[0], "r" )) == NULL || (*wfp = fdopen( p2c[1],
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"w" )) == NULL ) {
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Debug( LDAP_DEBUG_ANY, "fdopen failed\n", 0, 0, 0 );
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close( c2p[0] );
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close( p2c[1] );
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return( -1 );
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}
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return( pid );
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}
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