qmail-smtpd: Validation of recipient mailbox names.

[qmail] / addrcheck.c

diff --git a/addrcheck.c b/addrcheck.c
new file mode 100644 (file)
index 0000000..2ff9d13
--- /dev/null
+++ b/addrcheck.c
@@ -0,0 +1,181 @@
+#include "cdb.h"
+#include "stralloc.h"
+#include "byte.h"
+#include "str.h"
+#include "addrcheck.h"
+#include <errno.h>
+
+/* #define DEBUG */
+#ifdef DEBUG
+#  define D(x) x
+#  include <stdio.h>
+#  include <sys/types.h>
+#  include <unistd.h>
+#else
+#  define D(x)
+#endif
+
+#define STRALLOC_INIT { 0 }
+
+static int probe(int cdb, int prefix, const char *key, int len,
+                const char *suffix, uint32 *dlen)
+{
+  static stralloc k = STRALLOC_INIT;
+  char ch = prefix;
+  int rc;
+
+  k.len = 0;
+  if (!stralloc_append(&k, &ch) ||
+      !stralloc_catb(&k, key, len) ||
+      (suffix && !stralloc_cats(&k, suffix)))
+    return (-1);
+  D( fprintf(stderr, "*** `%.*s' -> ", k.len, k.s); )
+  rc = cdb_seek(cdb, k.s, k.len, dlen);
+  D( if (rc == -1)
+       fprintf(stderr, "error: %s\n", strerror(errno));
+     else if (rc == 0)
+       fprintf(stderr, "not found\n");
+     else if (!*dlen)
+       fprintf(stderr, "empty\n");
+     else {
+       int n = *dlen;
+       int nn;
+       char buf[256];
+       off_t pos = lseek(cdb, 0, SEEK_CUR);
+       fprintf(stderr, "`");
+       while (n) {
+        nn = sizeof(buf); if (nn > n) nn = n;
+        read(cdb, buf, nn);
+        fwrite(buf, 1, nn, stderr);
+        n -= nn;
+       }
+       fprintf(stderr, "'\n");
+       lseek(cdb, pos, SEEK_SET);
+     } )
+  return (rc);
+}
+
+static int localprobe(int cdb, const char *key, int len,
+                     const char *suffix, int *rc)
+{
+  int err;
+  uint32 dlen;
+  char ch;
+
+  if ((err = probe(cdb, 'L', key, len, suffix, &dlen)) < 0)
+    return (-1);
+  if (!err) { *rc = 0; return (0); }
+  if (dlen != 1) { errno = EINVAL; return (-1); }
+  if (read(cdb, &ch, 1) != 1) { errno = EIO; return (-1); }
+  *rc = ch;
+  return (1);
+}
+
+static int local(int cdb, const char *l, int len, int *rc)
+{
+  int code;
+  int err = 0;
+  int dash;
+
+  if ((err = localprobe(cdb, l, len, 0, &code)) != 0) goto done;
+
+  for (;;) {
+    dash = byte_rchr(l, len, '-');
+    if (dash == len) break;
+    if ((err = localprobe(cdb, l, dash, "-default", &code)) != 0) goto done;
+    len = dash;
+  }
+  *rc = 0;
+  return (0);
+  
+done:
+  if (err >= 0) {
+    switch (code) {
+      case '+': *rc = 1; break;
+      case '-': *rc = 0; break;
+      default: errno = EINVAL; err = -1; break;
+    }
+  }
+  return (err);
+}
+
+static int virt(int cdb, const char *u, int ulen,
+               const char *addr, int alen, int *rc)
+{
+  static stralloc l = STRALLOC_INIT;
+  uint32 dlen;
+  int err;
+
+  if ((err = probe(cdb, 'V', addr, alen, 0, &dlen)) <= 0)
+    return (err);
+  if (!stralloc_ready(&l, dlen + 1)) return (-1);
+  if (read(cdb, l.s, dlen) != dlen) { errno = EIO; return (-1); }
+  l.s[dlen] = '-';
+  l.len = dlen + 1;
+  if (!stralloc_catb(&l, u, ulen)) return (-1);
+  D( printf("*** virtual map -> `%.*s'\n", l.len, l.s); )
+  if (local(cdb, l.s, l.len, rc) < 0) return (-1);
+  return (1);
+}
+
+int addrcheck(int cdb, const char *addr, int *rc)
+{
+  int at, len, dot;
+  int err = 0;
+  uint32 dlen;
+
+  len = str_len(addr);
+  at = str_chr(addr, '@');
+  if (!addr[at])
+    return (local(cdb, addr, len, rc));
+
+  if ((err = virt(cdb, addr, at, addr, len, rc)) != 0)
+    return (err);
+  dot = at + 1;
+  while (addr[dot]) {
+    if ((err = virt(cdb, addr, at, addr + dot, len - dot, rc)) != 0)
+      return (err);
+    dot += byte_chr(addr + dot + 1, len - dot - 1, '.') + 1;
+  }
+
+  if ((err = probe(cdb, '@', addr + at + 1, len - at - 1, 0, &dlen)) < 0)
+    return (-1);
+  if (!err) { *rc = 1; return (0); }
+  if (dlen != 0) { errno = EINVAL; return (-1); }
+
+  return (local(cdb, addr, at, rc));
+}
+
+#ifdef TEST
+#include <sys/types.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[])
+{
+  int fd;
+  int rc;
+  int i;
+
+  if (argc < 3) {
+    fprintf(stderr, "usage: addrcheck CDB ADDR...\n");
+    return (1);
+  }
+  if ((fd = open(argv[1], O_RDONLY)) < 0) {
+    perror(argv[1]);
+    return (1);
+  }
+  for (i = 2; i < argc; i++) {
+    if (addrcheck(fd, argv[i], &rc) < 0) {
+      perror("checking");
+      return (1);
+    }
+    printf("%s: %s\n", argv[i], rc ? "ok" : "bad");
+  }
+  return (0);
+}
+
+#endif