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/*
* lookup_program.c
*
* Module for Linux automountd to access a automount map via a query program
*/
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <malloc.h>
#include <stdio.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/times.h>
#include <sys/types.h>
#include <sys/wait.h>
#define MODULE_LOOKUP
#include "automount.h"
#define MAPFMT_DEFAULT "sun"
#define MODPREFIX "lookup(program): "
#define MAPENT_MAX_LEN 4095
struct lookup_context {
char *mapname;
struct parse_mod *parse;
};
int lookup_version = AUTOFS_LOOKUP_VERSION; /* Required by protocol */
int lookup_init(char *mapfmt, int argc, char **argv, void **context)
{
struct lookup_context *ctxt;
if ( !(*context = ctxt = malloc(sizeof(struct lookup_context))) ) {
syslog(LOG_CRIT, MODPREFIX "malloc: %m");
return 1;
}
if ( argc < 1 ) {
syslog(LOG_CRIT, MODPREFIX "No map name");
return 1;
}
ctxt->mapname = argv[0];
if (ctxt->mapname[0] != '/') {
syslog(LOG_CRIT, MODPREFIX "program map %s is not an absolute pathname",
ctxt->mapname);
return 1;
}
if ( access(ctxt->mapname, X_OK) ) {
syslog(LOG_WARNING, MODPREFIX "program map %s missing or not executable",
ctxt->mapname);
}
if ( !mapfmt )
mapfmt = MAPFMT_DEFAULT;
return !(ctxt->parse = open_parse(mapfmt,MODPREFIX,argc-1,argv+1));
}
int lookup_mount(char *root, char *name, int name_len, void *context)
{
struct lookup_context *ctxt = (struct lookup_context *) context;
char mapent[MAPENT_MAX_LEN+1], *mapp;
char errbuf[1024], *errp;
char *p, ch;
int pipefd[2], epipefd[2];
pid_t f;
int files_left;
int status;
fd_set readfds, ourfds;
syslog(LOG_DEBUG, MODPREFIX "looking up %s", name);
/* We don't use popen because we don't want to run /bin/sh plus we
want to send stderr to the syslog, and we don't use spawnl()
because we need the pipe hooks */
if ( pipe(pipefd) ) {
syslog(LOG_ERR, MODPREFIX "pipe: %m");
return 1;
}
if ( pipe(epipefd) ) {
close(pipefd[0]);
close(pipefd[1]);
return 1;
}
f = fork();
if ( f < 0 ) {
close(pipefd[0]);
close(pipefd[1]);
close(epipefd[0]);
close(epipefd[1]);
syslog(LOG_ERR, MODPREFIX "fork: %m");
return 1;
} else if ( f == 0 ) {
close(pipefd[0]);
close(epipefd[0]);
dup2(pipefd[1],STDOUT_FILENO);
dup2(epipefd[1],STDERR_FILENO);
close(pipefd[1]);
close(epipefd[1]);
execl(ctxt->mapname, ctxt->mapname, name, NULL);
_exit(255); /* execl() failed */
}
close(pipefd[1]);
close(epipefd[1]);
mapp = mapent;
errp = errbuf;
FD_ZERO(&ourfds);
FD_SET(pipefd[0],&ourfds);
FD_SET(epipefd[0],&ourfds);
files_left = 2;
while (files_left) {
readfds = ourfds;
if ( select(OPEN_MAX, &readfds, NULL, NULL, NULL) < 0 &&
errno != EINTR )
break;
if ( FD_ISSET(pipefd[0],&readfds) ) {
if ( read(pipefd[0], &ch, 1) < 1 ) {
FD_CLR(pipefd[0], &ourfds);
files_left--;
} else if ( mapp ) {
if ( ch == '\n' ) {
*mapp = '\0';
mapp = NULL; /* End of line reached */
} else if ( mapp-mapent < MAPENT_MAX_LEN )
*(mapp++) = ch;
}
}
if ( FD_ISSET(epipefd[0],&readfds) ) {
if ( read(epipefd[0], &ch, 1) < 1 ) {
FD_CLR(epipefd[0], &ourfds);
files_left--;
} else if ( ch == '\n' ) {
*errp = '\0';
if ( errbuf[0] )
syslog(LOG_NOTICE, ">> %s", errbuf);
errp = errbuf;
} else {
if ( errp >= &errbuf[1023] ) {
*errp = '\0';
syslog(LOG_NOTICE, ">> %s", errbuf);
errp = errbuf;
}
*(errp++) = ch;
}
}
}
if ( mapp )
*mapp = '\0';
if ( errp > errbuf ) {
*errp = '\0';
syslog(LOG_NOTICE, ">> %s", errbuf);
}
close(pipefd[0]);
close(epipefd[0]);
if ( waitpid(f,&status,0) != f ) {
syslog(LOG_ERR, MODPREFIX "waitpid: %m");
return 1;
}
if ( mapp == mapent || !WIFEXITED(status) || WEXITSTATUS(status) != 0 ) {
syslog(LOG_NOTICE, MODPREFIX "lookup for %s failed", name);
return 1;
}
if ( (p = strchr(mapent,'\n')) ) *p = '\0';
syslog(LOG_DEBUG, MODPREFIX "%s -> %s", name, mapent);
return ctxt->parse->parse_mount(root,name,name_len,mapent,
ctxt->parse->context);
}
int lookup_done(void *context)
{
struct lookup_context *ctxt = (struct lookup_context *) context;
int rv = close_parse(ctxt->parse);
free(ctxt);
return rv;
}
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