updatehosts.c

A* sudo sudo/* B* adduser script adduser C* rmuser script rmuser E* tout tout/*

/*
** updatehosts - accept /etc/host file section updates via mail.
**
**  Accepts mail on stdin, then looks at body of message for:
**      # begin: foo
**
**  whereupon it writes this and all lines up to and including:
**      # end: foo
**
**  to the file HOSTDIR/foo... If a line of the format:
**      # adminmail: goober
**  is encountered an acknowledgment is sent to goober. 
**
**  If it sees: 
**      send
**  it will send the sender a copy of the current hosts file. If it
**  sees:
**      help
**  it will send the sender a copy of the help file
**
**
**  to make the program receive mail addressed to updatehosts,
**  add the following line to your /usr/lib/aliases file 
**	updatehosts: "|/usr/local/adm/hosts/updatehosts"
**
**  Written by Bob Coggeshall ([e-mail])
**
*/

#define JTY "Just thought you'd like to know.\n"

#include <stdio.h>
#include <ctype.h>
#include <sys/param.h>

#define HOSTDIR         "/usr/local/adm/hosts/hostsrc/"
#define HOSTS           "/usr/local/adm/hosts/hostsrc/hosts"
#define HELPFILE        "/usr/local/adm/hosts/doc/updatehosts.catme"
/** NEDITOR should be the name of the person allowed to edit  **/
#define NEDITOR         "coggs"
#define TEMPFILEPREF    "/tmp/updatehosts."
#define STDERR      	"/tmp/updatehosts.stderr"
#define UMASK		002

/** domainame contains your domain name **/
char *domainame = "colorado.edu";
char hostname[MAXHOSTNAMELEN];


/* values used by upexit() */

#define FAIL 1
#define FAKEFAIL 0		/* avoid generating mail bounces */
#define SUCCESS 0

/* values returned by parsline() */

#define BEGIN       1
#define END         2
#define ADMINMAIL   3
#define MAILHEAD    4
#define DATA        5
#define SEND        6
#define HELP        7
#define SUBJECT     8	

/* values used by mail() */

#define INDENT   1
#define NOINDENT 0

char *gets();
char *rindex();
char *index();
char *getcuradmin();
FILE *fopen();
FILE *freopen();

char *progname;

char wrkline[256];          /* yet another */
char wrkline1[256];         /* yet another 1 */

char realsender[256];       /* sender from the 'From ' line */
char curadminmail[256];     /* current value of 'Adminmail:' arg from file */

FILE *fd = NULL;            /* file descriptor for writing section file */
FILE *tfd = NULL;           /* file descriptor for temp file */
FILE *efd = NULL;           /* file descriptor for stderr */
char *cp;                   /* general purpose character pointer */
char tempfile[256];         /* name of temporary file */

main(ac,av)
int ac;
char **av;
{

    char arg[256];              /* rhs of arguments from input file */
    char line[256];             /* general purpose line buffer */
    char secfile[256];          /* name of section file */
    char secname[256];          /* name of section */
    char adminmail[256];        /* administrator mail arg */
    int pid;                    /* process id */
    int freadcount;             /* count returned from fread() */
    int systatus;               /* returned by system() */

	umask(UMASK);

    /*
    ** get the hostname and the program name.
    */
    gethostname(hostname,sizeof(hostname));

    if ((progname = rindex(*av,'/')) == 0)
        progname = *av;
    else
        progname++;

    /*
    ** redirect stderr to a file
    */
    if ( (efd = freopen(STDERR,"w+",stderr)) == NULL) {
        sprintf(wrkline, "%s: couldn't freopen() %s", progname,STDERR);
        mail(NEDITOR,wrkline, JTY,0,0);
    }

    /* 
    ** process input, parseline figures out what kind of line it is
    ** and this case statement decides what to do.
    */
    while (gets(line) != NULL)
    {
        switch (parseline(line,arg)) {

                case ADMINMAIL:         /* snarf adminmail arg */
                    if (tfd) {
                        fputs(line,tfd);
                        fputc('\n',tfd);
                    }
                    strcpy(adminmail,arg);
                    /*
                    ** check that old adminmail and new adminmail args match
                    */
                    strcpy(wrkline,adminmail);
                    if ((cp = index(wrkline,'@')) != 0) 
                            *cp = '\0';

                    strcpy(wrkline1,curadminmail);
                    if ((cp = index(wrkline1,'@')) != 0) 
                            *cp = '\0';

                    if ( (strncmp(wrkline,wrkline1,sizeof(wrkline)) != 0) ) {
                        sprintf(wrkline,
			"%s: new adminmail:%s and current adminmail: %s  don't match",
                        progname,adminmail,curadminmail);
                        mail(NEDITOR,wrkline, JTY,0,0);
                        upexit(FAKEFAIL);
                    }
                    break;

                case MAILHEAD:          /* its the mail header, skip it */
                    strcpy(realsender,arg); /* snarf sender */
					fprintf(stderr,"realsender: %s\n",realsender);
                    break;

                case SUBJECT: 
                    break;

                case SEND:          /* they want a copy of the whole thing */
                    sprintf(wrkline,"%s: copy of current hosts file:",progname);
                    mail(realsender,wrkline,"",HOSTS,NOINDENT);

                    sprintf(wrkline,"%s: sent %s copy of current hosts file",
                            progname,realsender);
                    mail(NEDITOR,wrkline,JTY,0,0);

                    upexit(SUCCESS);

                    break;

                case HELP:          /* send them the help file */
                    sprintf(wrkline,"%s: help file",progname);
                    mail(realsender,wrkline,"",HELPFILE,NOINDENT);

                    sprintf(wrkline,"%s: sent %s the help file",
                            progname,realsender);
                    mail(NEDITOR,wrkline,JTY,0,0);

                    upexit(SUCCESS);
                    break;

                case DATA:              /* its data, snarf it. */
                    if (tfd) {
                        fputs(line,tfd);
                        fputc('\n',tfd);
                    }
                    break;

                case BEGIN:             
                    /*
                    ** if begin, then see if section file exists
                    ** if it doesn't send mail and die. if it does
                    ** open it tempfile for write.
                    */
                    strcpy(secfile,HOSTDIR);
                    strcpy(secname,arg);
                    strcat(secfile,secname);

                    if (access(secfile,0) != 0) {
                        sprintf(wrkline,"%s: Can't access() %s",
                        progname,secfile);
                        mail(NEDITOR,wrkline,
                        "File needs to exist before i'll overwrite it",0,0);
                        upexit(FAKEFAIL);
                    }
                
                    /* 
                    ** read secfile and get the current adminmail: arg
                    ** and authenticate by comparing it with sender
                    */
                    strcpy(curadminmail,getcuradmin(secfile));

                    strcpy(wrkline,curadminmail);
                    if ((cp = index(wrkline,'@')) != 0) 
                            *cp = '\0';

                    strcpy(wrkline1,realsender);
                    if ((cp = index(wrkline1,'@')) != 0) 
                            *cp = '\0';

                    if ( (strncmp(wrkline,wrkline1,sizeof(wrkline)) != 0) ) {
                    /*
                    ** some exceptions....
                    */
                    strcpy(wrkline,NEDITOR);
                    if ((cp  = index(wrkline,'@')) != 0)
                        *cp = '\0';
                    if ( (strncmp(wrkline,wrkline1,sizeof(wrkline)) == 0)|| 
                        strncmp(wrkline,"root",sizeof("root")) == 0)
                        goto except;

                    sprintf(wrkline,
                    "%s: sender: %s and current adminmail: %s don't match",
                    progname,realsender,curadminmail);
                    mail(NEDITOR,wrkline, JTY,0,0);
                    upexit(FAKEFAIL);
                }
            except:

                    /*
                    ** open temporary file.
                    */
                    pid = getpid(); 
                    sprintf(tempfile,"%s%d",TEMPFILEPREF,pid);
                    if ( (tfd = fopen(tempfile,"w+")) == 0) {
                        sprintf(wrkline,"%s: Can't fopen() %s",
                        progname,tempfile);
                        mail(NEDITOR,wrkline,JTY,0,0);
                        upexit(FAKEFAIL);
                    }

                    if ( (fputs("##\n",tfd)) == EOF) {
                        sprintf(wrkline,"%s: %s: Write failed", 
                        progname, tempfile);
                        mail(NEDITOR,wrkline,JTY,0,0);
                        upexit(FAKEFAIL);
                    }
                    fputs(line,tfd);
                    fputc('\n',tfd);
                    break;

                case END:
                    /*
                    **   if end then close file, make sure begin and
                    **  end agree. complain and die if not. otherwise
                    **  send mail that things are ok
                    */
                    strcpy(wrkline,HOSTDIR);
                    strcat(wrkline,arg);

                    if (strncmp(wrkline,secfile,strlen(tempfile)) != 0) {
                        sprintf(wrkline,"%s %s",NEDITOR,adminmail);
                        sprintf(wrkline1,
                        "%s: 'End:' arg disagreed with 'Begin:' arg",progname);
                        mail(wrkline,wrkline1,JTY,0,0);
                        upexit(FAKEFAIL);
                    }

                    fputs(line,tfd);
                    fputc('\n',tfd);
                    fputs("##\n",tfd);
                    (void)fseek(tfd,0L,0);

                    if ( (fd = fopen(secfile,"w")) == 0) {
                        sprintf(wrkline,"%s: Can't fopen() %s",
                        progname,secfile);
                        mail(NEDITOR,wrkline,JTY,0,0);
                        upexit(FAKEFAIL);
                    }

                    while( (freadcount = fread(wrkline, 
                                        sizeof(*wrkline),
                                        sizeof(wrkline),tfd))  > 0)

                        if ((fwrite(wrkline,