Initial revision
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@3 ec53bebd-3082-4978-b11e-865c3cabbd6b
This commit is contained in:
Björn Groenvall
161
appl/popper/pop_dropcopy.c
Normal file
161
appl/popper/pop_dropcopy.c
Normal file
@@ -0,0 +1,161 @@
|
||||
/*
|
||||
* Copyright (c) 1989 Regents of the University of California.
|
||||
* All rights reserved. The Berkeley software License Agreement
|
||||
* specifies the terms and conditions for redistribution.
|
||||
*/
|
||||
|
||||
#ifndef lint
|
||||
static char copyright[] = "Copyright (c) 1990 Regents of the University of California.\nAll rights reserved.\n";
|
||||
static char SccsId[] = "@(#)@(#)pop_dropcopy.c 2.6 2.6 4/3/91";
|
||||
#endif not lint
|
||||
|
||||
#include <errno.h>
|
||||
#include <stdio.h>
|
||||
#include <sys/types.h>
|
||||
#include <strings.h>
|
||||
#include <sys/stat.h>
|
||||
#include <sys/file.h>
|
||||
#include <pwd.h>
|
||||
#include "popper.h"
|
||||
|
||||
extern int errno;
|
||||
extern int sys_nerr;
|
||||
extern char *sys_errlist[];
|
||||
|
||||
/*
|
||||
* dropcopy: Make a temporary copy of the user's mail drop and
|
||||
* save a stream pointer for it.
|
||||
*/
|
||||
|
||||
pop_dropcopy(p,pwp)
|
||||
POP * p;
|
||||
struct passwd * pwp;
|
||||
{
|
||||
int mfd; /* File descriptor for
|
||||
the user's maildrop */
|
||||
int dfd; /* File descriptor for
|
||||
the SERVER maildrop */
|
||||
FILE *tf; /* The temp file */
|
||||
char template[POP_TMPSIZE]; /* Temp name holder */
|
||||
char buffer[BUFSIZ]; /* Read buffer */
|
||||
long offset; /* Old/New boundary */
|
||||
int nchar; /* Bytes written/read */
|
||||
struct stat mybuf; /* For lstat() */
|
||||
|
||||
/* Create a temporary maildrop into which to copy the updated maildrop */
|
||||
(void)sprintf(p->temp_drop,POP_DROP,p->user);
|
||||
|
||||
#ifdef DEBUG
|
||||
if(p->debug)
|
||||
pop_log(p,POP_DEBUG,"Creating temporary maildrop '%s'",
|
||||
p->temp_drop);
|
||||
#endif DEBUG
|
||||
|
||||
/* Here we work to make sure the user doesn't cause us to remove or
|
||||
* write over existing files by limiting how much work we do while
|
||||
* running as root.
|
||||
*/
|
||||
|
||||
/* First create a unique file. Would prefer mkstemp, but Ultrix...*/
|
||||
strcpy(template,POP_TMPDROP);
|
||||
(void) mktemp(template);
|
||||
if ( (tf=fopen(template,"w+")) == NULL ) { /* failure, bail out */
|
||||
pop_log(p,POP_PRIORITY,
|
||||
"Unable to create temporary temporary maildrop '%s': %s",template,
|
||||
(errno < sys_nerr) ? sys_errlist[errno] : "") ;
|
||||
return pop_msg(p,POP_FAILURE,
|
||||
"System error, can't create temporary file.");
|
||||
}
|
||||
|
||||
/* Now give this file to the user */
|
||||
(void) chown(template,pwp->pw_uid, pwp->pw_gid);
|
||||
(void) chmod(template,0600);
|
||||
|
||||
/* Now link this file to the temporary maildrop. If this fails it
|
||||
* is probably because the temporary maildrop already exists. If so,
|
||||
* this is ok. We can just go on our way, because by the time we try
|
||||
* to write into the file we will be running as the user.
|
||||
*/
|
||||
(void) link(template,p->temp_drop);
|
||||
(void) fclose(tf);
|
||||
(void) unlink(template);
|
||||
|
||||
/* Now we run as the user. */
|
||||
(void) setuid(pwp->pw_uid);
|
||||
(void) setgid(pwp->pw_gid);
|
||||
|
||||
#ifdef DEBUG
|
||||
if(p->debug)pop_log(p,POP_DEBUG,"uid = %d, gid = %d",getuid(),getgid());
|
||||
#endif DEBUG
|
||||
|
||||
/* Open for append, this solves the crash recovery problem */
|
||||
if ((dfd = open(p->temp_drop,O_RDWR|O_APPEND|O_CREAT,0600)) == -1){
|
||||
pop_log(p,POP_PRIORITY,
|
||||
"Unable to open temporary maildrop '%s': %s",p->temp_drop,
|
||||
(errno < sys_nerr) ? sys_errlist[errno] : "") ;
|
||||
return pop_msg(p,POP_FAILURE,
|
||||
"System error, can't open temporary file, do you own it?");
|
||||
}
|
||||
|
||||
/* Lock the temporary maildrop */
|
||||
if ( flock (dfd, LOCK_EX|LOCK_NB) == -1 )
|
||||
switch(errno) {
|
||||
case EWOULDBLOCK:
|
||||
return pop_msg(p,POP_FAILURE,
|
||||
"Maildrop lock busy! Is another session active?");
|
||||
/* NOTREACHED */
|
||||
default:
|
||||
return pop_msg(p,POP_FAILURE,"flock: '%s': %s", p->temp_drop,
|
||||
(errno < sys_nerr) ? sys_errlist[errno] : "");
|
||||
/* NOTREACHED */
|
||||
}
|
||||
|
||||
/* May have grown or shrunk between open and lock! */
|
||||
offset = lseek(dfd,0,L_XTND);
|
||||
|
||||
/* Open the user's maildrop, If this fails, no harm in assuming empty */
|
||||
if ((mfd = open(p->drop_name,O_RDWR)) > 0) {
|
||||
|
||||
/* Lock the maildrop */
|
||||
if (flock (mfd,LOCK_EX) == -1) {
|
||||
(void)close(mfd) ;
|
||||
return pop_msg(p,POP_FAILURE, "flock: '%s': %s", p->temp_drop,
|
||||
(errno < sys_nerr) ? sys_errlist[errno] : "");
|
||||
}
|
||||
|
||||
/* Copy the actual mail drop into the temporary mail drop */
|
||||
while ( (nchar=read(mfd,buffer,BUFSIZ)) > 0 )
|
||||
if ( nchar != write(dfd,buffer,nchar) ) {
|
||||
nchar = -1 ;
|
||||
break ;
|
||||
}
|
||||
|
||||
if ( nchar != 0 ) {
|
||||
/* Error adding new mail. Truncate to original size,
|
||||
and leave the maildrop as is. The user will not
|
||||
see the new mail until the error goes away.
|
||||
Should let them process the current backlog, in case
|
||||
the error is a quota problem requiring deletions! */
|
||||
(void)ftruncate(dfd,(int)offset) ;
|
||||
} else {
|
||||
/* Mail transferred! Zero the mail drop NOW, that we
|
||||
do not have to do gymnastics to figure out what's new
|
||||
and what is old later */
|
||||
(void)ftruncate(mfd,0) ;
|
||||
}
|
||||
|
||||
/* Close the actual mail drop */
|
||||
(void)close (mfd);
|
||||
}
|
||||
|
||||
/* Acquire a stream pointer for the temporary maildrop */
|
||||
if ( (p->drop = fdopen(dfd,"a+")) == NULL ) {
|
||||
(void)close(dfd) ;
|
||||
return pop_msg(p,POP_FAILURE,"Cannot assign stream for %s",
|
||||
p->temp_drop);
|
||||
}
|
||||
|
||||
rewind (p->drop);
|
||||
|
||||
return(POP_SUCCESS);
|
||||
}
|
||||
Reference in New Issue
Block a user