Re: your mail
Joseph W. Stroup (nettech@crl.com)
Sun, 2 Oct 1994 19:33:26 -0700 (PDT)
This is got to stop now ! Everyone of these I get I will bounce to the
SENDER!
Joseph Stroup
On Sun, 2 Oct 1994, Tim Newsham wrote:
> #ifndef lint
> static char sccsid[] = "@(#)mail.c 1.1 90/10/29 SMI; from UCB 4.15 83/04/12";
> #endif
>
> /*
> * /bin/mail - local delivery
> */
> #include <sys/types.h>
> #include <sys/stat.h>
> #include <sys/file.h>
>
> #include <ctype.h>
> #include <stdio.h>
> #include <pwd.h>
> #include <utmp.h>
> #include <signal.h>
> #include <setjmp.h>
> #include <sysexits.h>
>
> #define SENDMAIL "/usr/lib/sendmail"
>
> /* copylet flags */
> #define REMOTE 1 /* remote mail, add rmtmsg */
> #define ORDINARY 2
> #define ZAP 3 /* zap header and trailing empty line */
> #define FORWARD 4
>
> #define LSIZE 256
> #define MAXLET 300 /* maximum number of letters */
> #define MAILMODE 0600 /* mode of created mail */
>
> char line[LSIZE];
> char resp[LSIZE];
> struct let {
> long adr;
> char change;
> } let[MAXLET];
> int nlet = 0;
> char lfil[50];
> long iop, time();
> char *getenv();
> char *index();
> char lettmp[] = "/tmp/maXXXXX";
> char maildir[] = "/var/spool/mail/";
> char mailfile[] = "/var/spool/mail/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
> char dead[] = "dead.letter";
> char forwmsg[] = " forwarded\n";
> FILE *tmpf;
> FILE *malf;
> char *my_name;
> char *getlogin();
> int error;
> int changed;
> int forward;
> char from[] = "From ";
> long ftell();
> void delex();
> char *ctime();
> int flgf;
> int flgp;
> int flge;
> int flgt;
> int delflg = 1;
> int hseqno;
> jmp_buf sjbuf;
> int rmail;
>
> main(argc, argv)
> char **argv;
> {
> register i;
> struct passwd *pwent;
>
> mktemp(lettmp);
> unlink(lettmp);
> my_name = getlogin();
> if (my_name == NULL || *my_name == '\0') {
> pwent = getpwuid(getuid());
> if (pwent==NULL)
> my_name = "???";
> else
> my_name = pwent->pw_name;
> }
> else {
> pwent = getpwnam(my_name);
> if ( getuid() != pwent->pw_uid) {
> pwent = getpwuid(getuid());
> my_name = pwent->pw_name;
> }
> }
> if (setjmp(sjbuf))
> done();
> for (i=SIGHUP; i<=SIGTERM; i++)
> setsig(i, delex);
> tmpf = fopen(lettmp, "w+r");
> if (tmpf == NULL)
> panic("mail: %s: cannot open for writing", lettmp);
> /*
> * This protects against others reading mail from temp file and
> * if we exit, the file will be deleted already.
> */
> unlink(lettmp);
> if (argv[0][0] == 'r')
> rmail++;
> if (argv[0][0] != 'r' && /* no favors for rmail*/
> (argc == 1 || argv[1][0] == '-' && !any(argv[1][1], "hdt")
> && (argv[argc-1][0] == '-' || argv[argc-2][1] == 'f')))
> /* -r can be an option in both
> * cases. If last arg is an option
> * or it's an argument to -f
> * call printmail; otherwise (it's
> * a user name), call bulkmail.
> */
> printmail(argc, argv);
> else
> bulkmail(argc, argv);
> done();
> /* NOTREACHED */
> }
>
> setsig(i, f)
> int i;
> void (*f)();
> {
> if (signal(i, SIG_IGN) != SIG_IGN)
> signal(i, f);
> }
>
> any(c, str)
> register int c;
> register char *str;
> {
>
> while (*str)
> if (c == *str++)
> return(1);
> return(0);
> }
>
> printmail(argc, argv)
> char **argv;
> {
> int flg, i, j, print;
> char *p, *getarg();
> struct stat statb;
>
> setuid(getuid());
> cat(mailfile, maildir, my_name);
> for (; argc > 1; argv++, argc--) {
> if (argv[1][0] != '-')
> break;
> switch (argv[1][1]) {
>
> case 'p':
> flgp++;
> /* fall thru... */
> case 'q':
> delflg = 0;
> break;
>
> case 'f':
> if (argv[1][2] == '\0') {
> if (argc >= 3) {
> strcpy(mailfile, argv[2]);
> argv++, argc--;
> }
> }
> else
> strcpy(mailfile, &argv[1][2]);
> break;
>
> case 'r':
> forward = 1;
> break;
>
> case 'e':
> flge++;
> break;
>
> default:
> panic("unknown option %c", argv[1][1]);
> /*NOTREACHED*/
> }
> }
> malf = fopen(mailfile, "r");
> if (malf == NULL) {
> if (!flge) {
> printf("No mail.\n");
> return;
> }
> else {
> fclose(tmpf);
> error = 1;
> done();
> }
> }
> lock(mailfile);
> copymt(malf, tmpf);
> fclose(malf);
> unlock();
>
> /* if e option given, dont' need to go any further */
> if (flge) {
> fclose(tmpf);
> if (nlet)
> done();
> else {
> error = 1;
> done();
> }
> }
>
> fseek(tmpf, 0, L_SET);
>
> changed = 0;
> print = 1;
> for (i = 0; i < nlet; ) {
> j = forward ? i : nlet - i - 1;
> if (setjmp(sjbuf)) {
> print = 0;
> } else {
> if (print)
> copylet(j, stdout, ORDINARY);
> print = 1;
> }
> if (flgp) {
> i++;
> continue;
> }
> setjmp(sjbuf);
> printf( "? ");
> fflush(stdout);
> if (fgets(resp, LSIZE, stdin) == NULL)
> break;
> switch (resp[0]) {
>
> default:
> printf("usage\n");
> case '?':
> case '*':
> print = 0;
> printf("q\tquit\n");
> printf("x\texit without changing mail\n");
> printf("p\tprint\n");
> printf("s[file]\tsave (default mbox)\n");
> printf("w[file]\tsame without header\n");
> printf("-\tprint previous\n");
> printf("d\tdelete\n");
> printf("+\tnext (no delete)\n");
> printf("m user\tmail to user\n");
> printf("! cmd\texecute cmd\n");
> break;
>
> case '+':
> case 'n':
> case '\n':
> i++;
> break;
> case 'x':
> changed = 0;
> case 'q':
> goto donep;
> case 'p':
> break;
> case '^':
> case '-':
> if (--i < 0)
> i = 0;
> break;
> case 'y':
> case 'w':
> case 's':
> flg = 0;
> if (resp[1] != '\n' && resp[1] != ' ') {
> printf("illegal\n");
> flg++;
> print = 0;
> continue;
> }
> if (resp[1] == '\n' || resp[1] == '\0') {
> p = getenv("HOME");
> if (p != 0)
> cat(resp+1, p, "/mbox");
> else
> cat(resp+1, "", "mbox");
> }
> for (p = resp+1; (p = getarg(lfil, p)) != NULL; ) {
> malf = fopen(lfil, "a");
> if (malf == NULL) {
> printf("mail: %s: cannot append\n",
> lfil);
> flg++;
> continue;
> }
> copylet(j, malf, resp[0]=='w'? ZAP: ORDINARY);
> fclose(malf);
> }
> if (flg)
> print = 0;
> else {
> let[j].change = 'd';
> changed++;
> i++;
> }
> break;
> case 'm':
> flg = 0;
> if (resp[1] == '\n' || resp[1] == '\0') {
> i++;
> continue;
> }
> if (resp[1] != ' ') {
> printf("invalid command\n");
> flg++;
> print = 0;
> continue;
> }
> for (p = resp+1; (p = getarg(lfil, p)) != NULL; )
> if (!sendmail(j, lfil, my_name))
> /* couldn't send it */
> flg++;
> if (flg)
> print = 0;
> else {
> let[j].change = 'd';
> changed++;
> i++;
> }
> break;
> case '!':
> system(resp+1);
> printf("!\n");
> print = 0;
> break;
> case 'd':
> let[j].change = 'd';
> changed++;
> i++;
> if (resp[1] == 'q')
> goto donep;
> break;
> }
> }
> donep:
> if (changed)
> copyback();
> }
>
> /* copy temp or whatever back to /var/spool/mail */
> copyback()
> {
> register i, c;
> int fd, new = 0, oldmask;
> struct stat stbuf;
>
> #define mask(s) (1 << ((s) - 1))
> oldmask = sigblock(mask(SIGINT)|mask(SIGHUP)|mask(SIGQUIT));
> #undef mask
> lock(mailfile);
> fd = open(mailfile, O_RDWR | O_CREAT, MAILMODE);
> if (fd >= 0) {
> malf = fdopen(fd, "r+w");
> }
> if (fd < 0 || malf == NULL)
> panic("can't rewrite %s", lfil);
> fstat(fd, &stbuf);
> if (stbuf.st_size != let[nlet].adr) { /* new mail has arrived */
> fseek(malf, let[nlet].adr, L_SET);
> fseek(tmpf, let[nlet].adr, L_SET);
> while ((c = getc(malf)) != EOF)
> putc(c, tmpf);
> let[++nlet].adr = stbuf.st_size;
> new = 1;
> fseek(malf, 0, L_SET);
> }
> ftruncate(fd, 0);
> for (i = 0; i < nlet; i++)
> if (let[i].change != 'd')
> copylet(i, malf, ORDINARY);
> fclose(malf);
> if (new)
> printf("New mail has arrived.\n");
> unlock();
> sigsetmask(oldmask);
> }
>
> /* copy mail (f1) to temp (f2) */
> copymt(f1, f2)
> FILE *f1, *f2;
> {
> long nextadr;
>
> nlet = nextadr = 0;
> let[0].adr = 0;
> while (fgets(line, LSIZE, f1) != NULL) {
> if (isfrom(line))
> let[nlet++].adr = nextadr;
> nextadr += strlen(line);
> fputs(line, f2);
> }
> let[nlet].adr = nextadr; /* last plus 1 */
> }
>
> copylet(n, f, type)
> FILE *f;
> {
> int ch;
> long k;
> char hostname[32];
>
>
> fseek(tmpf, let[n].adr, L_SET);
> k = let[n+1].adr - let[n].adr;
> while (k-- > 1 && (ch = getc(tmpf)) != '\n')
> if (type != ZAP)
> putc(ch, f);
> switch (type) {
>
> case REMOTE:
> gethostname(hostname, sizeof (hostname));
> fprintf(f, " remote from %s\n", hostname);
> break;
>
> case FORWARD:
> fprintf(f, forwmsg);
> break;
>
> case ORDINARY:
> putc(ch, f);
> break;
>
> case ZAP:
> break;
>
> default:
> panic("Bad letter type %d to copylet.", type);
> }
> while (k-- > 1) {
> ch = getc(tmpf);
> putc(ch, f);
> }
> if (type != ZAP || ch != '\n')
> putc(getc(tmpf), f);
> }
>
> isfrom(lp)
> register char *lp;
> {
> register char *p;
>
> for (p = from; *p; )
> if (*lp++ != *p++)
> return(0);
> return(1);
> }
>
> bulkmail(argc, argv)
> char **argv;
> {
> int aret;
> char **args;
> char truename[100];
> int first;
> register char *cp;
> char *newargv[1000];
> register char **ap;
> register char **vp;
> int dflag;
> int a_count=0;
> int gaver=0;
>
> dflag = 0;
> if (argc < 1) {
> fprintf(stderr, "puke\n");
> return;
> }
> for (vp = argv, ap = newargv + 1; (*ap = *vp++) != 0; ap++)
> if (ap[0][0] == '-' && ap[0][1] == 'd')
> dflag++;
> if (!dflag) {
> /* give it to sendmail, rah rah! */
> unlink(lettmp);
> ap = newargv+1;
> if (rmail)
> *ap-- = "-s";
> *ap = "-sendmail";
> setuid(getuid());
> execv(SENDMAIL, ap);
> perror(SENDMAIL);
> exit(EX_UNAVAILABLE);
> }
>
> truename[0] = 0;
> line[0] = '\0';
>
> /*
> * When we fall out of this, argv[1] should be first name,
> * argc should be number of names + 1.
> */
>
> while (argc > 1 && *argv[1] == '-') {
> cp = *++argv;
> argc--;
> a_count++;
> switch (cp[1]) {
> case 'r':
> if (argc <= 1)
> usage();
> gaver++;
> strcpy(truename, argv[1]);
> fgets(line, LSIZE, stdin);
> if (strncmp("From", line, 4) == 0)
> line[0] = '\0';
> argv++;
> argc--;
> break;
> case 'h':
> if (argc <= 1)
> usage();
> hseqno = atoi(argv[1]);
> argv++;
> argc--;
> break;
>
> case 't':
> flgt++;
> break;
>
> case 'd':
> break;
>
> default:
> usage();
> }
> }
> if (argc <= 1)
> usage();
> if (rmail && ((a_count>1) || (a_count==1 && !flgt)))
> usage();
> if (gaver == 0)
> strcpy(truename, my_name);
>
> time(&iop);
> fprintf(tmpf, "%s%s %s", from, truename, ctime(&iop));
>
> /* Copy to list in mail entry? */
> if (flgt && argc > 0 ) {
> aret = argc;
> args = argv;
> fprintf(tmpf,"To: ");
> while (--aret > 0)
> fprintf(tmpf,"%s ", *++args);
> fprintf(tmpf,"\n");
> }
>
> iop = ftell(tmpf);
> flgf = first = 1;
> for (;;) {
> if (first) {
> first = 0;
> if (*line == '\0' && fgets(line, LSIZE, stdin) == NULL)
> break;
> } else {
> if (fgets(line, LSIZE, stdin) == NULL)
> break;
> }
> if (*line == '.' && line[1] == '\n' && isatty(fileno(stdin)))
> break;
> if (isfrom(line))
> putc('>', tmpf);
> fputs(line, tmpf);
> flgf = 0;
> }
> putc('\n', tmpf);
> nlet = 1;
> let[0].adr = 0;
> let[1].adr = ftell(tmpf);
> if (flgf)
> return;
> while (--argc > 0)
> if (!sendmail(0, *++argv, truename))
> error++;
> if (error) {
> /* Don't return count of errors, return a defined code. */
> error = EX_UNAVAILABLE;
>
> /* Also, try to save dead.letter */
> if (safefile(dead)) {
> setuid(getuid());
> malf = fopen(dead, "w");
> if (malf == NULL) {
> printf( "mail: cannot open %s\n", dead);
> fclose(tmpf);
> return;
> }
> copylet(0, malf, ZAP);
> fclose(malf);
> printf( "Mail saved in %s\n", dead);
> }
> }
> fclose(tmpf);
> }
>
> sendrmt(n, name)
> char *name;
> {
> FILE *rmf, *popen();
> register char *p;
> char rsys[64], cmd[64];
> register pid;
> int sts;
>
> for (p=rsys; *name!='!'; *p++ = *name++)
> if (*name=='\0')
> return(0); /* local address, no '!' */
> *p = '\0';
> if (name[1]=='\0') {
> printf("null name\n");
> return(0);
> }
> skip:
> if ((pid = fork()) == -1) {
> fprintf(stderr, "mail: can't create proc for remote\n");
> return(0);
> }
> if (pid) {
> while (wait(&sts) != pid) {
> if (wait(&sts)==-1)
> return(0);
> }
> return(!sts);
> }
> setuid(getuid());
> if (any('!', name+1))
> sprintf(cmd, "uux - %s!rmail \\(%s\\)", rsys, name+1);
> else
> sprintf(cmd, "uux - %s!rmail %s", rsys, name+1);
> if ((rmf=popen(cmd, "w")) == NULL)
> exit(1);
> copylet(n, rmf, REMOTE);
> exit(pclose(rmf) != 0);
> }
>
> usage()
> {
>
> fprintf(stderr, "Usage: mail [-r] [-t] [-p] [-q] [-e] [-h seqno] [-f fname] [people] . . .\n");
> error = EX_USAGE;
> done();
> }
>
> #include <sys/socket.h>
> #include <netinet/in.h>
>
> notifybiff(msg)
> char *msg;
> {
> static struct sockaddr_in addr;
> static int f = -1;
>
> if (addr.sin_family == 0) {
> addr.sin_family = AF_INET;
> addr.sin_addr.s_addr = INADDR_ANY;
> addr.sin_port = htons(IPPORT_BIFFUDP);
> }
> if (f < 0)
> f = socket(AF_INET, SOCK_DGRAM, 0);
> sendto(f, msg, strlen(msg)+1, 0, &addr, sizeof (addr));
> }
>
> sendmail(n, name, fromaddr)
> int n;
> char *name;
> char *fromaddr;
> {
> char file[256];
> int fd;
> struct passwd *pw;
> char buf[128];
> int realuser;
>
> if (*name=='!')
> name++;
> if (any('!', name))
> return (sendrmt(n, name));
> if ((pw = getpwnam(name)) == NULL) {
> printf("mail: can't send to %s\n", name);
> return(0);
> }
> cat(file, maildir, name);
> if (!safefile(file))
> return(0);
> /*
> * Remember the real UID, and temporarily become the target
> * user in case we are going across NFS
> */
> realuser = getuid();
> setreuid(0,pw->pw_uid);
> lock(file);
> fd = open(file, O_WRONLY | O_CREAT, MAILMODE);
> if (fd >= 0) {
> flock(fd, LOCK_EX);
> malf = fdopen(fd, "a");
> }
> if (fd < 0 || malf == NULL) {
> unlock();
> close(fd);
> printf("mail: %s: cannot append\n", file);
> setuid(0);
> setreuid(realuser,0);
> return(0);
> }
> setuid(0);
> setreuid(realuser,0);
> fchown(fd, pw->pw_uid, pw->pw_gid);
> sprintf(buf, "%s@%d\n", name, ftell(malf));
> copylet(n, malf, ORDINARY);
> fclose(malf);
> setreuid(0,pw->pw_uid);
> unlock();
> notifybiff(buf);
> setuid(0);
> setreuid(realuser,0);
> return(1);
> }
>
> void
> delex(i)
> {
> setsig(i, delex);
> putc('\n', stderr);
> if (delflg)
> longjmp(sjbuf, 1);
> done();
> }
>
> /*
> * Lock the specified mail file by setting the file mailfile.lock.
> * We must, of course, be careful to unlink the lock file by a call
> * to unlock before we stop. The algorithm used here is to see if
> * the lock exists, and if it does, to check its modify time. If it
> * is older than 300 seconds, we assume error and set our own file.
> * Otherwise, we wait for 5 seconds and try again.
> */
>
> char *maillock = ".lock"; /* Lock suffix for mailname */
> char *lockname = "/var/spool/mail/tmXXXXXX";
> char locktmp[30]; /* Usable lock temporary */
> char curlock[50]; /* Last used name of lock */
> int locked; /* To note that we locked it */
>
> lock(file)
> char *file;
> {
> register time_t t;
> struct stat sbuf;
> int statfailed;
>
> if (locked || flgf)
> return(0);
> strcpy(curlock, file);
> strcat(curlock, maillock);
> strcpy(locktmp, lockname);
> mktemp(locktmp);
> unlink(locktmp);
> statfailed = 0;
> for (;;) {
> t = lock1(locktmp, curlock);
> if (t == 0) {
> locked = 1;
> return(0);
> }
> if (stat(curlock, &sbuf) < 0) {
> if (statfailed++ > 5)
> return(-1);
> sleep(5);
> continue;
> }
> statfailed = 0;
>
> /*
> * Compare the time of the temp file with the time
> * of the lock file, rather than with the current
> * time of day, since the files may reside on
> * another machine whose time of day differs from
> * ours. If the lock file is less than 5 minutes
> * old, keep trying.
> */
> if (t < sbuf.st_ctime + 300) {
> sleep(5);
> continue;
> }
> unlink(curlock);
> }
> }
>
> /*
> * Remove the mail lock, and note that we no longer
> * have it locked.
> */
>
> unlock()
> {
>
> unlink(curlock);
> locked = 0;
> }
>
> /*
> * Attempt to set the lock by creating the temporary file,
> * then doing a link/unlink. If it succeeds, return 0,
> * else return a guess of the current time on the machine
> * holding the file.
> */
>
> lock1(tempfile, name)
> char tempfile[], name[];
> {
> register int fd;
> struct stat sbuf;
>
> fd = creat(tempfile, 0);
> if (fd < 0)
> return(time(0));
> fstat(fd, &sbuf);
> close(fd);
> if (link(tempfile, name) < 0) {
> unlink(tempfile);
> return(sbuf.st_ctime);
> }
> unlink(tempfile);
> return(0);
> }
>
> done()
> {
> if(locked)
> unlock();
> unlink(lettmp);
> unlink(locktmp);
> exit(error);
> }
>
> cat(to, from1, from2)
> char *to, *from1, *from2;
> {
> register char *cp, *dp;
>
> cp = to;
> for (dp = from1; *cp = *dp++; cp++)
> ;
> for (dp = from2; *cp++ = *dp++; )
> ;
> }
>
> /* copy p... into s, update p */
> char *
> getarg(s, p)
> register char *s, *p;
> {
> while (*p == ' ' || *p == '\t')
> p++;
> if (*p == '\n' || *p == '\0')
> return(NULL);
> while (*p != ' ' && *p != '\t' && *p != '\n' && *p != '\0')
> *s++ = *p++;
> *s = '\0';
> return(p);
> }
>
> safefile(f)
> char *f;
> {
> struct stat statb;
>
> if (lstat(f, &statb) < 0)
> return (1);
> if (statb.st_nlink != 1 || (statb.st_mode & S_IFMT) == S_IFLNK) {
> fprintf(stderr,
> "mail: %s has more than one link or is a symbolic link\n",
> f);
> return (0);
> }
> return (1);
> }
>
> panic(msg, a1, a2, a3)
> char *msg;
> {
>
> fprintf(stderr, "mail: ");
> fprintf(stderr, msg, a1, a2, a3);
> fprintf(stderr, "\n");
> error = EX_OSERR;
> done();
> }
>