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#ifndef lint |
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static const char RCSid[] = "$Id: netproc.c,v 2.13 2003/11/10 16:52:24 greg Exp $"; |
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#endif |
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/* |
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* Parallel network process handling routines |
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*/ |
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|
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#include <stdlib.h> |
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#include <stdio.h> |
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#include <string.h> |
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#include <signal.h> |
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#include <fcntl.h> |
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#include <unistd.h> |
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|
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#include "selcall.h" |
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#include "netproc.h" |
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#include "paths.h" |
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|
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PSERVER *pslist = NULL; /* global process server list */ |
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|
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static NETPROC *pindex[FD_SETSIZE]; /* process index table */ |
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|
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static char ourhost[64]; /* this host name */ |
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static char ourdir[PATH_MAX]; /* our working directory */ |
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static char ouruser[32]; /* our user name */ |
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static char *ourshell; /* our user's shell */ |
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|
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static fd_set errdesc; /* error file descriptors */ |
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static int maxfd; /* maximum assigned descriptor */ |
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|
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extern char *remsh; /* externally defined remote shell program */ |
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|
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|
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PSERVER * |
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addpserver(host, dir, usr, np) /* add a new process server */ |
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char *host, *dir, *usr; |
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int np; |
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{ |
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register PSERVER *ps; |
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/* allocate the struct */ |
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if (np < 1) |
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return(NULL); |
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ps = (PSERVER *)malloc(sizeof(PSERVER)+(np-1)*sizeof(NETPROC)); |
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if (ps == NULL) |
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return(NULL); |
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if (!ourhost[0]) { /* initialize */ |
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char dirtmp[PATH_MAX]; |
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register char *cp; |
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register int len; |
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|
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strcpy(ourhost, myhostname()); |
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getcwd(dirtmp, sizeof(dirtmp)); |
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if ((cp = getenv("HOME")) != NULL) { |
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if (!strcmp(cp, dirtmp)) |
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ourdir[0] = '\0'; |
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else if (!strncmp(cp, dirtmp, len=strlen(cp)) && |
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dirtmp[len] == '/') |
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strcpy(ourdir, dirtmp+len+1); |
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else |
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strcpy(ourdir, dirtmp); |
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} else |
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strcpy(ourdir, dirtmp); |
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if ((cp = getenv("USER")) != NULL) |
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strcpy(ouruser, cp); |
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if ((ourshell = getenv("SHELL")) == NULL) |
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ourshell = "/bin/sh"; |
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FD_ZERO(&errdesc); |
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maxfd = -1; |
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} |
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/* assign host, directory, user */ |
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if (host == NULL || !strcmp(host, ourhost) || |
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!strcmp(host, LHOSTNAME)) |
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ps->hostname[0] = '\0'; |
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else |
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strcpy(ps->hostname, host); |
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if (dir == NULL) |
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strcpy(ps->directory, ourdir); |
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else |
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strcpy(ps->directory, dir); |
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if (usr == NULL || !strcmp(usr, ouruser)) |
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ps->username[0] = '\0'; |
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else |
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strcpy(ps->username, usr); |
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/* clear process slots */ |
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ps->nprocs = np; |
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while (np--) { |
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ps->proc[np].com = NULL; |
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ps->proc[np].pid = -1; |
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ps->proc[np].efd = -1; |
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ps->proc[np].errs = NULL; |
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ps->proc[np].elen = 0; |
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ps->proc[np].cf = NULL; |
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} |
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/* insert in our list */ |
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ps->next = pslist; |
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pslist = ps; |
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/* check for signs of life */ |
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if (!pserverOK(ps)) { |
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delpserver(ps); /* failure -- abort */ |
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return(NULL); |
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} |
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return(ps); |
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} |
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|
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|
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delpserver(ps) /* delete a process server */ |
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PSERVER *ps; |
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{ |
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PSERVER pstart; |
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register PSERVER *psp; |
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register int i; |
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/* find server in our list */ |
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pstart.next = pslist; |
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for (psp = &pstart; ps != psp->next; psp = psp->next) |
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if (psp->next == NULL) |
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return; /* not in our list! */ |
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/* kill any running jobs */ |
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for (i = 0; i < ps->nprocs; i++) |
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if (ps->proc[i].com != NULL) { |
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kill(SIGTERM, ps->proc[i].pid); |
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wait4job(ps, ps->proc[i].pid); |
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} |
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/* remove server from list */ |
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psp->next = ps->next; |
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pslist = pstart.next; |
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free((void *)ps); /* free associated memory */ |
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} |
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|
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|
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PSERVER * |
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findjob(pnp) /* find out where process is running */ |
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register int *pnp; /* modified */ |
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{ |
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register PSERVER *ps; |
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register int i; |
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|
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for (ps = pslist; ps != NULL; ps = ps->next) |
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for (i = 0; i < ps->nprocs; i++) |
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if (ps->proc[i].pid == *pnp) { |
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*pnp = i; |
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return(ps); |
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} |
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return(NULL); /* not found */ |
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} |
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|
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|
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int |
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startjob(ps, command, compf) /* start a job on a process server */ |
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register PSERVER *ps; |
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char *command; |
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int (*compf)(); |
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{ |
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char udirt[PATH_MAX]; |
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char *av[16]; |
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int pfd[2], pid; |
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register int i; |
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|
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if (ps == NULL) { /* find a server */ |
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for (ps = pslist; ps != NULL; ps = ps->next) |
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if ((i = startjob(ps, command, compf)) != -1) |
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return(i); /* got one */ |
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return(-1); /* no slots anywhere */ |
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} |
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for (i = 0; i < ps->nprocs; i++) |
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if (ps->proc[i].com == NULL) |
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break; |
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if (i >= ps->nprocs) |
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return(-1); /* out of process slots */ |
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/* open pipe */ |
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if (pipe(pfd) < 0) { |
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perror("cannot open pipe"); |
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exit(1); |
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} |
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/* start child process */ |
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if ((pid = fork()) == 0) { |
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close(pfd[0]); /* connect stderr to pipe */ |
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if (pfd[1] != 2) { |
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dup2(pfd[1], 2); |
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close(pfd[1]); |
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} |
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if (ps->hostname[0]) { /* rsh command */ |
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av[i=0] = remsh; |
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av[++i] = ps->hostname; |
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av[++i] = "-n"; /* no stdin */ |
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if (ps->username[0]) { /* different user */ |
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av[++i] = "-l"; |
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av[++i] = ps->username; |
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av[++i] = "cd"; |
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udirt[0] = '~'; |
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strcpy(udirt+1, ouruser); |
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av[++i] = udirt; |
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av[++i] = ";"; |
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} |
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if (ps->directory[0]) { /* change directory */ |
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av[++i] = "cd"; |
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av[++i] = ps->directory; |
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av[++i] = ";"; |
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} |
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av[++i] = command; |
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av[++i] = NULL; |
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} else { /* shell command */ |
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av[0] = ourshell; |
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av[1] = "-c"; |
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av[2] = command; |
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av[3] = NULL; |
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} |
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execv(av[0], av); |
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_exit(1); |
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} |
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if (pid == -1) { |
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perror("fork failed"); |
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exit(1); |
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} |
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ps->proc[i].com = command; /* assign process slot */ |
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ps->proc[i].cf = compf; |
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ps->proc[i].pid = pid; |
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close(pfd[1]); /* get piped stderr file descriptor */ |
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ps->proc[i].efd = pfd[0]; |
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fcntl(pfd[0], F_SETFD, 1); /* set close on exec flag */ |
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pindex[pfd[0]] = ps->proc + i; /* assign error fd index */ |
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FD_SET(pfd[0], &errdesc); /* add to select call parameter */ |
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if (pfd[0] > maxfd) |
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maxfd = pfd[0]; |
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return(pid); /* return to parent process */ |
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} |
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|
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|
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static int |
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readerrs(fd) /* read error output from fd */ |
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int fd; |
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{ |
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char errbuf[BUFSIZ]; |
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int nr; |
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register NETPROC *pp; |
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/* look up associated process */ |
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if ((pp = pindex[fd]) == NULL) |
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abort(); /* serious consistency error */ |
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nr = read(fd, errbuf, BUFSIZ-1); |
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if (nr < 0) { |
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perror("read error"); |
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exit(1); |
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} |
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if (nr == 0) /* stream closed (process finished) */ |
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return(0); |
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errbuf[nr] = '\0'; /* add to error buffer */ |
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if (pp->elen == 0) |
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pp->errs = (char *)malloc(nr+1); |
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else |
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pp->errs = (char *)realloc((void *)pp->errs, pp->elen+nr+1); |
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if (pp->errs == NULL) { |
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perror("malloc failed"); |
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exit(1); |
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} |
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strcpy(pp->errs+pp->elen, errbuf); |
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pp->elen += nr; |
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return(nr); |
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} |
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|
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|
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static |
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wait4end() /* read error streams until someone is done */ |
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{ |
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fd_set readfds, excepfds; |
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register int i; |
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/* find end of descriptor set */ |
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for ( ; maxfd >= 0; maxfd--) |
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if (FD_ISSET(maxfd, &errdesc)) |
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break; |
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if (maxfd < 0) |
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return; /* nothing to read */ |
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readfds = excepfds = errdesc; |
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while (select(maxfd+1, &readfds, NULL, &excepfds, NULL) > 0) |
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for (i = 0; i <= maxfd; i++) /* get pending i/o */ |
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if (FD_ISSET(i, &readfds) || FD_ISSET(i, &excepfds)) |
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if (readerrs(i) == 0) |
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return; /* finished process */ |
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perror("select call failed"); |
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exit(1); |
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} |
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|
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|
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static int |
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finishjob(ps, pn, status) /* clean up finished process */ |
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PSERVER *ps; |
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int pn; |
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int status; |
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{ |
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register NETPROC *pp; |
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|
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pp = ps->proc + pn; |
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if (pp->cf != NULL) /* client cleanup */ |
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status = (*pp->cf)(ps, pn, status); |
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close(pp->efd); /* close error stream */ |
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pindex[pp->efd] = NULL; |
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FD_CLR(pp->efd, &errdesc); |
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free((void *)pp->errs); |
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pp->com = NULL; /* clear settings */ |
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pp->pid = -1; |
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pp->efd = -1; |
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pp->errs = NULL; |
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pp->elen = 0; |
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pp->cf = NULL; |
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return(status); |
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} |
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|
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|
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int |
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wait4job(ps, pid) /* wait for process to finish */ |
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PSERVER *ps; |
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int pid; |
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{ |
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int status, psn, psn2; |
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PSERVER *ps2; |
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|
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if (pid == -1) { /* wait for first job */ |
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if (ps != NULL) { |
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for (psn = ps->nprocs; psn--; ) |
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if (ps->proc[psn].com != NULL) |
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break; |
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if (psn < 0) |
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return(-1); /* no processes this server */ |
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} |
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do { |
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wait4end(); /* wait for something to end */ |
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if ((psn2 = wait(&status)) == -1) |
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return(-1); /* none left */ |
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ps2 = findjob(&psn2); |
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if (ps2 != NULL) /* clean up job if ours */ |
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status = finishjob(ps2, psn2, status); |
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} while (ps2 == NULL || (ps != NULL && ps2 != ps)); |
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return(status); /* return job status */ |
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} |
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psn = pid; /* else find specific job */ |
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ps2 = findjob(&psn); /* find process slot */ |
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if (ps2 == NULL || (ps != NULL && ps2 != ps)) |
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return(-1); /* inconsistent target */ |
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ps = ps2; |
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do { |
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wait4end(); /* wait for something to end */ |
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if ((psn2 = wait(&status)) == -1) |
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return(-1); /* none left */ |
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ps2 = findjob(&psn2); |
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if (ps2 != NULL) /* clean up job if ours */ |
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status = finishjob(ps2, psn2, status); |
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} while (ps2 != ps || psn2 != psn); |
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return(status); /* return job status */ |
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} |