ref: bf645afaac246967b9590ae7463f243c11d97480
dir: /sys/src/cmd/upas/scanmail/scanmail.c/
#include "common.h"
#include <regexp.h>
#include "spam.h"
int cflag;
int debug;
int hflag;
int nflag;
int sflag;
int tflag;
int vflag;
Biobuf bin, bout, *cout;
/* file names */
char patfile[128];
char linefile[128];
char holdqueue[128];
char copydir[128];
char header[Hdrsize+2];
char cmd[1024];
char **qname;
char **qdir;
char *sender;
String *recips;
char* canon(Biobuf*, char*, char*, int*);
int matcher(char*, Pattern*, char*, Resub*);
int matchaction(int, char*, Resub*);
Biobuf *opencopy(char*);
Biobuf *opendump(char*);
char *qmail(char**, char*, int, Biobuf*);
void saveline(char*, char*, Resub*);
int optoutofspamfilter(char*);
void
usage(void)
{
fprint(2, "usage: scanmail [-cdhnstv] [-p pattern] [-q queuename] sender dest sys\n");
exits("usage");
}
void
regerror(char *s)
{
fprint(2, "scanmail: %s\n", s);
}
void *
Malloc(long n)
{
void *p;
p = malloc(n);
if(p == nil)
sysfatal("malloc: %r");
return p;
}
void*
Realloc(void *p, ulong n)
{
p = realloc(p, n);
if(p == nil)
sysfatal("malloc: %r");
setrealloctag(p, getcallerpc(&p));
return p;
}
void
main(int argc, char *argv[])
{
int i, n, nolines, optout;
char **args, **a, *cp, *buf;
char body[Bodysize+2];
Resub match[1];
Biobuf *bp;
optout = 1;
a = args = Malloc((argc+1)*sizeof(char*));
snprint(patfile, sizeof patfile, "%s/patterns", UPASLIB);
snprint(linefile, sizeof linefile, "%s/lines", UPASLOG);
snprint(holdqueue, sizeof holdqueue, "%s/queue.hold", SPOOL);
snprint(copydir, sizeof copydir, "%s/copy", SPOOL);
*a++ = argv[0];
for(argc--, argv++; argv[0] && argv[0][0] == '-'; argc--, argv++){
switch(argv[0][1]){
case 'c': /* save copy of message */
cflag = 1;
break;
case 'd': /* debug */
debug++;
*a++ = argv[0];
break;
case 'h': /* queue held messages by sender domain */
hflag = 1; /* -q flag must be set also */
break;
case 'n': /* NOHOLD mode */
nflag = 1;
break;
case 'p': /* pattern file */
if(argv[0][2] || argv[1] == 0)
usage();
argc--;
argv++;
strecpy(patfile, patfile+sizeof patfile, *argv);
break;
case 'q': /* queue name */
if(argv[0][2] || argv[1] == 0)
usage();
*a++ = argv[0];
argc--;
argv++;
qname = a;
*a++ = argv[0];
break;
case 's': /* save copy of dumped message */
sflag = 1;
break;
case 't': /* test mode - don't log match
* and write message to /dev/null
*/
tflag = 1;
break;
case 'v': /* vebose - print matches */
vflag = 1;
break;
default:
*a++ = argv[0];
break;
}
}
if(argc < 3)
usage();
Binit(&bin, 0, OREAD);
bp = Bopen(patfile, OREAD);
if(bp){
parsepats(bp);
Bterm(bp);
}
qdir = a;
sender = argv[2];
/* copy the rest of argv, acummulating the recipients as we go */
for(i = 0; argv[i]; i++){
*a++ = argv[i];
if(i < 4) /* skip queue, 'mail', sender, dest sys */
continue;
/* recipients and smtp flags - skip the latter*/
if(strcmp(argv[i], "-g") == 0){
*a++ = argv[++i];
continue;
}
if(recips)
s_append(recips, ", ");
else
recips = s_new();
s_append(recips, argv[i]);
if(optout && !optoutofspamfilter(argv[i]))
optout = 0;
}
*a = 0;
/* construct a command string for matching */
snprint(cmd, sizeof(cmd)-1, "%s %s", sender, s_to_c(recips));
cmd[sizeof(cmd)-1] = 0;
for(cp = cmd; *cp; cp++)
*cp = tolower(*cp);
/* canonicalize a copy of the header and body.
* buf points to orginal message and n contains
* number of bytes of original message read during
* canonicalization.
*/
*body = 0;
*header = 0;
buf = canon(&bin, header+1, body+1, &n);
if (buf == 0)
exits("read");
/* if all users opt out, don't try matches */
if(optout){
if(cflag)
cout = opencopy(sender);
exits(qmail(args, buf, n, cout));
}
/* Turn off line logging, if command line matches */
nolines = matchaction(Lineoff, cmd, match);
for(i = 0; patterns[i].action; i++){
/* Lineoff patterns were already done above */
if(i == Lineoff)
continue;
/* don't apply "Line" patterns if excluded above */
if(nolines && i == SaveLine)
continue;
/* apply patterns to the sender/recips, header and body */
if(matchaction(i, cmd, match))
break;
if(matchaction(i, header+1, match))
break;
if(i == HoldHeader)
continue;
if(matchaction(i, body+1, match))
break;
}
if(cflag && patterns[i].action == 0) /* no match found - save msg */
cout = opencopy(sender);
exits(qmail(args, buf, n, cout));
}
char*
qmail(char **argv, char *buf, int n, Biobuf *cout)
{
Waitmsg *status;
int i, pid, pipefd[2];
char path[512];
Biobuf *bp;
pid = 0;
if(tflag == 0){
if(pipe(pipefd) < 0)
exits("pipe");
pid = fork();
if(pid == 0){
dup(pipefd[0], 0);
for(i = sysfiles(); i >= 3; i--)
close(i);
snprint(path, sizeof(path), "%s/qer", UPASBIN);
*argv=path;
exec(path, argv);
exits("exec");
}
Binit(&bout, pipefd[1], OWRITE);
bp = &bout;
} else
bp = Bopen("/dev/null", OWRITE);
while(n > 0){
Bwrite(bp, buf, n);
if(cout)
Bwrite(cout, buf, n);
n = Bread(&bin, buf, sizeof(buf)-1);
}
Bterm(bp);
if(cout)
Bterm(cout);
if(tflag)
return 0;
close(pipefd[1]);
close(pipefd[0]);
for(;;){
status = wait();
if(status == nil || status->pid == pid)
break;
free(status);
}
if(status == nil)
strcpy(buf, "wait failed");
else{
strcpy(buf, status->msg);
free(status);
}
return buf;
}
char*
canon(Biobuf *bp, char *header, char *body, int *n)
{
int hsize;
char *raw;
hsize = 0;
*header = 0;
*body = 0;
raw = readmsg(bp, &hsize, n);
if(raw){
if(convert(raw, raw+hsize, header, Hdrsize, 0))
conv64(raw+hsize, raw+*n, body, Bodysize); /* base64 */
else
convert(raw+hsize, raw+*n, body, Bodysize, 1); /* text */
}
return raw;
}
int
matchaction(int action, char *message, Resub *m)
{
char *name;
Pattern *p;
if(message == 0 || *message == 0)
return 0;
name = patterns[action].action;
p = patterns[action].strings;
if(p)
if(matcher(name, p, message, m))
return 1;
for(p = patterns[action].regexps; p; p = p->next)
if(matcher(name, p, message, m))
return 1;
return 0;
}
int
matcher(char *action, Pattern *p, char *message, Resub *m)
{
char *cp;
String *s;
for(cp = message; matchpat(p, cp, m); cp = m->ep){
switch(p->action){
case SaveLine:
if(vflag)
xprint(2, action, m);
saveline(linefile, sender, m);
break;
case HoldHeader:
case Hold:
if(nflag)
continue;
if(vflag)
xprint(2, action, m);
*qdir = holdqueue;
if(hflag && qname){
cp = strchr(sender, '!');
if(cp){
*cp = 0;
*qname = strdup(sender);
*cp = '!';
} else
*qname = strdup(sender);
}
return 1;
case Dump:
if(vflag)
xprint(2, action, m);
*(m->ep) = 0;
if(!tflag){
s = s_new();
s_append(s, sender);
s = unescapespecial(s);
syslog(0, "smtpd", "Dumped %s [%s] to %s", s_to_c(s), m->sp,
s_to_c(s_restart(recips)));
s_free(s);
}
tflag = 1;
if(sflag)
cout = opendump(sender);
return 1;
default:
break;
}
}
return 0;
}
void
saveline(char *file, char *sender, Resub *rp)
{
char *p, *q;
int i, c;
Biobuf *bp;
if(rp->sp == 0 || rp->ep == 0)
return;
/* back up approx 20 characters to whitespace */
for(p = rp->sp, i = 0; *p && i < 20; i++, p--)
;
while(*p && *p != ' ')
p--;
p++;
/* grab about 20 more chars beyond the end of the match */
for(q = rp->ep, i = 0; *q && i < 20; i++, q++)
;
while(*q && *q != ' ')
q++;
c = *q;
*q = 0;
bp = sysopen(file, "al", 0644);
if(bp){
Bprint(bp, "%s-> %s\n", sender, p);
Bterm(bp);
}
else if(debug)
fprint(2, "can't save line: (%s) %s\n", sender, p);
*q = c;
}
Biobuf*
opendump(char *sender)
{
int i;
Tm tm;
ulong h;
char buf[512];
Biobuf *b;
char *cp, mon[8], day[4];
tmnow(&tm, nil);
snprint(mon, sizeof(mon), "%τ", tmfmt(&tm, "MMM"));
snprint(day, sizeof(day), "%τ", tmfmt(&tm, "D"));
snprint(buf, sizeof buf, "%s/queue.dump/%s%s", SPOOL, mon, day);
cp = buf+strlen(buf);
if(access(buf, 0) < 0 && sysmkdir(buf, 0777) < 0){
syslog(0, "smtpd", "couldn't dump mail from %s: %r", sender);
return 0;
}
h = 0;
while(*sender)
h = h*257 + *sender++;
for(i = 0; i < 50; i++){
h += lrand();
seprint(cp, buf+sizeof buf, "/%lud", h);
b = sysopen(buf, "wlc", 0644);
if(b){
if(vflag)
fprint(2, "saving in %s\n", buf);
return b;
}
}
return 0;
}
Biobuf*
opencopy(char *sender)
{
int i;
ulong h;
char buf[512];
Biobuf *b;
h = 0;
while(*sender)
h = h*257 + *sender++;
for(i = 0; i < 50; i++){
h += lrand();
snprint(buf, sizeof buf, "%s/%lud", copydir, h);
b = sysopen(buf, "wlc", 0600);
if(b)
return b;
}
return 0;
}
int
optoutofspamfilter(char *addr)
{
char *p, *f;
int rv;
p = strchr(addr, '!');
if(p)
p++;
else
p = addr;
rv = 0;
f = smprint("/mail/box/%s/nospamfiltering", p);
if(f != nil){
rv = access(f, 0)==0;
free(f);
}
return rv;
}