ref: 8bebe3ab193201f2bd9c32328e229bf36fd2ad82
dir: /sys/src/cmd/upas/spf/macro.c/
#include "spf.h"
#define mrprint(...) snprint(m->mreg, sizeof m->mreg, __VA_ARGS__)
typedef struct Mfmt Mfmt;
typedef struct Macro Macro;
struct Mfmt{
char buf[0xff];
char *p;
char *e;
char mreg[0xff];
int f1;
int f2;
int f3;
char *sender;
char *domain;
char *ip;
char *helo;
uchar ipa[IPaddrlen];
};
struct Macro{
char c;
void (*f)(Mfmt*);
};
static void
ms(Mfmt *m)
{
mrprint("%s", m->sender);
}
static void
ml(Mfmt *m)
{
char *p;
mrprint("%s", m->sender);
if(p = strchr(m->mreg, '@'))
*p = 0;
}
static void
mo(Mfmt *m)
{
mrprint("%s", m->domain);
}
static void
md(Mfmt *m)
{
mrprint("%s", m->domain);
}
static void
mi(Mfmt *m)
{
uint i, c;
if(isv4(m->ipa))
mrprint("%s", m->ip);
else{
for(i = 0; i < 32; i++){
c = m->ipa[i / 2];
if((i & 1) == 0)
c >>= 4;
sprint(m->mreg+2*i, "%ux.", c & 0xf);
}
m->mreg[2*32 - 1] = 0;
}
}
static int
maquery(Mfmt *m, char *d, char *match, int recur)
{
int r;
Ndbtuple *t, *n;
r = 0;
t = vdnsquery(d, "any", recur);
for(n = t; n; n = n->entry)
if(!strcmp(n->attr, "ip") || !strcmp(n->attr, "ipv6")){
if(!strcmp(n->val, match)){
r = 1;
break;
}
}else if(!strcmp(n->attr, "cname"))
maquery(m, d, match, recur+1);
ndbfree(t);
return r;
}
static int
lrcmp(char *a, char *b)
{
return strlen(b) - strlen(a);
}
static void
mptrquery(Mfmt *m, char *d, int recur)
{
char *s, buf[64], *a, *list[11];
int nlist, i;
Ndbtuple *t, *n;
nlist = 0;
dnreverse(buf, sizeof buf, s = strdup(m->ip));
t = vdnsquery(buf, "ptr", recur);
for(n = t; n; n = n->entry){
if(!strcmp(n->attr, "dom") || !strcmp(n->attr, "cname"))
if(dncontains(n->val, d) && maquery(m, n->val, m->ip, recur+1))
list[nlist++] = strdup(n->val);
}
ndbfree(t);
free(s);
qsort(list, nlist, sizeof *list, (int(*)(void*,void*))lrcmp);
a = "unknown";
for(i = 0; i < nlist; i++)
if(!strcmp(list[i], d)){
a = list[i];
break;
}else if(dncontains(list[i], d))
a = list[i];
mrprint("%s", a);
for(i = 0; i < nlist; i++)
free(list[i]);
}
static void
mp(Mfmt *m)
{
/*
* we're supposed to do a reverse lookup on the ip & compare.
* this is a very bad idea.
*/
// mrprint("unknown); /* simulate dns failure */
mptrquery(m, m->domain, 0);
}
static void
mv(Mfmt *m)
{
if(isv4(m->ipa))
mrprint("in-addr");
else
mrprint("ip6");
}
static void
mh(Mfmt *m)
{
mrprint("%s", m->helo);
}
static Macro tab[] = {
's', ms, /* sender */
'l', ml, /* local part of sender */
'o', mo, /* domain of sender */
'd', md, /* domain */
'i', mi, /* ip */
'p', mp, /* validated domain name of ip */
'v', mv, /* "in-addr" if ipv4, or "ip6" if ipv6 */
'h', mh, /* helo/ehol domain */
};
static void
reverse(Mfmt *m)
{
char *p, *e, buf[100], *f[32], sep[2];
int i, n;
sep[0] = m->f2;
sep[1] = 0;
n = getfields(m->mreg, f, nelem(f), 0, sep);
p = e = buf;
e += sizeof buf-1;
for(i = 0; i < n; i++)
p = seprint(p, e, "%s.", f[n-i-1]);
if(p > buf)
p--;
*p = 0;
memmove(m->mreg, buf, p-buf+1);
m->f2 = '.';
}
static void
chop(Mfmt *m)
{
char *p, *e, buf[100], *f[32], sep[2];
int i, n;
sep[0] = m->f2;
sep[1] = 0;
n = getfields(m->mreg, f, nelem(f), 0, sep);
p = e = buf;
e += sizeof buf-1;
if(m->f1 == 0)
i = 0;
else
i = n-m->f1;
if(i < 0)
i = 0;
for(; i < n; i++)
p = seprint(p, e, "%s.", f[i]);
if(p > buf)
p--;
*p = 0;
memmove(m->mreg, buf, p-buf+1);
m->f2 = '.';
}
static void
mfmtinit(Mfmt *m, char *s, char *d, char *h, char *i)
{
memset(m, 0, sizeof *m);
m->p = m->buf;
m->e = m->p + sizeof m->buf-1;
m->sender = s? s: "Unsets";
m->domain = d? d: "Unsetd";
m->helo = h? h: "Unseth";
m->ip = i? i: "127.0.0.2";
parseip(m->ipa, m->ip);
}
/* url escaping? rfc3986 */
static void
mputc(Mfmt *m, int c)
{
if(m->p < m->e)
*m->p++ = c;
}
static void
mputs(Mfmt *m, char *s)
{
int c;
while(c = *s++)
mputc(m, c);
}
char*
macro(char *f, char *sender, char *dom, char *hdom, char *ip)
{
char *p;
int i, c;
Mfmt m;
mfmtinit(&m, sender, dom, hdom, ip);
while(*f){
while((c = *f++) && c != '%')
mputc(&m, c);
if(c == 0)
break;
switch(*f++){
case '%':
mputc(&m, '%');
break;
case '-':
mputs(&m, "%20");
break;
case '_':
mputc(&m, ' ');
break;
case '{':
m.f1 = 0;
m.f2 = '.';
m.f3 = 0;
c = *f++;
if(c >= 'A' && c <= 'Z')
c += 0x20;
for(i = 0; i < nelem(tab); i++)
if(tab[i].c == c)
break;
if(i == nelem(tab))
return 0;
for(c = *f++; c >= '0' && c <= '9'; c = *f++)
m.f1 = m.f1*10 + c-'0';
if(c == 'R' || c == 'r'){
m.f3 = 'r';
c = *f++;
}
for(; p = strchr(".-+,_=", c); c = *f++)
m.f2 = *p;
if(c == '}'){
tab[i].f(&m);
if(m.f1 || m.f2 != '.')
chop(&m);
if(m.f3 == 'r')
reverse(&m);
mputs(&m, m.mreg);
m.mreg[0] = 0;
break;
}
default:
return 0;
}
}
mputc(&m, 0);
return strdup(m.buf);
}