Initial commit

1 files changed, 169 insertions, 0 deletions

diff --git a/src/minidentd/mgetuid-linux.c b/src/minidentd/mgetuid-linux.c
new file mode 100644
index 0000000..442f642
--- /dev/null
+++ b/src/minidentd/mgetuid-linux.c
@@ -0,0 +1,169 @@
+/* ISC license. */
+
+#include <skalibs/uint16.h>
+#include <skalibs/uint32.h>
+#include <skalibs/uint.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/fmtscan.h>
+#include <skalibs/buffer.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/ip46.h>
+#include <skalibs/skamisc.h>
+#include "mgetuid.h"
+
+#ifdef DEBUG
+#include <skalibs/strerr2.h>
+#define bug(a) do { strerr_warn4x("bug parsing ", a, "remaining: ", cur) ; return 0 ; } while (0)
+#else
+#define bug(a) return 0
+#endif
+
+#define LINESIZE 256
+
+static int skipspace (char **s)
+{
+  while (**s && ((**s == ' ') || (**s == '\t')))
+    (*s)++ ;
+  return (int)**s ;
+}
+
+static int parseline (char *s, unsigned int len, unsigned int *u, char *la, uint16 *lp, char *ra, uint16 *rp, int is6)
+{
+  char *cur = s ;
+  unsigned int pos ;
+  uint32 junk ;
+  register unsigned int iplen = is6 ? 16 : 4 ;
+
+  if (!skipspace(&cur)) bug("initial whitespace") ;
+  pos = uint32_scan(cur, &junk) ;  /* sl */
+  if (!pos || (cur-s+1+pos) > len) bug("sl") ;
+  cur += pos ;
+  if ((*cur++) != ':') bug("sl:") ;
+  if (!skipspace(&cur)) bug("sl: SPACE") ;
+
+  if ((cur - s + 1 + iplen) > len) bug("local_address") ;
+  pos = ucharn_scan(cur, la, iplen) ;  /* local_address */
+  if (!pos) bug("local_address") ;
+  cur += pos ;
+  if ((*cur++) != ':') bug("local_address:") ;
+
+  pos = uint16_xscan(cur, lp) ;  /* :port */
+  if (!pos || (cur-s+pos) > len) bug("local_port") ;
+  cur += pos ;
+  if (!skipspace(&cur)) bug("local_port SPACE") ;
+
+  if ((cur - s + 1 + iplen) > len) bug("remote_address") ;
+  pos = ucharn_scan(cur, ra, iplen) ;  /* remote_address */
+  if (!pos) bug("remote_address") ;
+  cur += pos ;
+  if ((*cur++) != ':') bug("remote_address:") ;
+
+  pos = uint16_xscan(cur, rp) ;  /* :port */
+  if (!pos || (cur-s+pos) > len) bug("remote_port") ;
+  cur += pos ;
+  if (!skipspace(&cur)) bug("remote_port SPACE");
+
+  pos = uint32_xscan(cur, &junk) ;  /* st */
+  if (!pos || (cur-s+pos) > len) bug("st") ;
+  cur += pos ;
+  if (!skipspace(&cur)) bug("st SPACE") ;
+  pos = uint32_xscan(cur, &junk) ;  /* tx_queue */
+  if (!pos || (cur-s+1+pos) > len) bug("tx_queue") ;
+  cur += pos ;
+  if ((*cur++) != ':') bug("tx_queue:") ;
+  pos = uint32_xscan(cur, &junk) ;  /* rx_queue */
+  if (!pos || (cur-s+pos) > len) bug("rx_queue") ;
+  cur += pos ;
+  if (!skipspace(&cur)) bug("rx_queue SPACE") ;
+  pos = uint32_xscan(cur, &junk) ;  /* tr */
+  if (!pos || (cur-s+1+pos) > len) bug("tr") ;
+  cur += pos ;
+  if ((*cur++) != ':') bug("tr:") ;
+  pos = uint32_xscan(cur, &junk) ;  /* tm->when */
+  if (!pos || (cur-s+pos) > len) bug("tm->when") ;
+  cur += pos ;
+  if (!skipspace(&cur)) bug("tm->when SPACE") ;
+  pos = uint32_xscan(cur, &junk) ;  /* retrnsmt */
+  if (!pos || (cur-s+pos) > len) bug("retrnsmt") ;
+  cur += pos ;
+
+  if (!skipspace(&cur)) bug("retrnsmt SPACE") ;
+  pos = uint_scan(cur, u) ;  /* uid */
+  if (!pos || (cur-s+1+pos) > len) bug("uid") ;
+
+  return 1 ;
+}
+
+#ifdef DEBUG
+
+static void debuglog (uint16 a, uint16 b, unsigned int c, char const *d, char const *e, int is6)
+{
+  char sa[UINT16_FMT] ;
+  char sb[UINT16_FMT] ;
+  char sc[UINT_FMT] ;
+  char sd[IP46_FMT] ;
+  char se[IP46_FMT] ;
+
+  sa[uint16_fmt(sa, a)] = 0 ;
+  sb[uint16_fmt(sb, b)] = 0 ;
+  sc[uint_fmt(sc, c)] = 0 ;
+  sd[is6 ? ip6_fmt(sd, d) : ip4_fmt(sd, d)] = 0 ;
+  se[is6 ? ip6_fmt(se, e) : ip4_fmt(se, e)] = 0 ;
+
+  buffer_puts(buffer_2, sd) ;
+  buffer_puts(buffer_2, ":") ;
+  buffer_puts(buffer_2, sa) ;
+  buffer_puts(buffer_2, " , ") ;
+  buffer_puts(buffer_2, se) ;
+  buffer_puts(buffer_2, ":") ;
+  buffer_puts(buffer_2, sb) ;
+  buffer_puts(buffer_2, " -> ") ;
+  buffer_puts(buffer_2, sc) ;
+  buffer_putsflush(buffer_2, "\n") ;
+}
+
+#endif
+
+int mgetuid (ip46_t const *localaddr, uint16 localport, ip46_t const *remoteaddr, uint16 remoteport)
+{
+  int r ;
+  int u = -2 ;
+  stralloc line = STRALLOC_ZERO ;
+  buffer b ;
+  char y[BUFFER_INSIZE] ;
+  register int is6 = ip46_is6(localaddr) ;
+  int fd = open_readb(is6 ? "/proc/net/tcp6" : "/proc/net/tcp") ;
+  if (fd == -1) return -2 ;
+  buffer_init(&b, &buffer_read, fd, y, BUFFER_INSIZE_SMALL) ;
+  if (skagetln(&b, &line, '\n') < 1) goto err ;
+#ifdef DEBUG
+  line.s[line.len-1] = 0 ;
+  debuglog(localport, remoteport, 65535, localaddr->ip, remoteaddr->ip, is6) ;
+#endif
+  for (;;)
+  {
+    char la[16] ;
+    char ra[16] ;
+    unsigned int nu ;
+    uint16 lp, rp ;
+    line.len = 0 ;
+    r = skagetln(&b, &line, '\n') ;
+    if (r <= 0) { u = -1 ; break ; }
+    line.s[line.len-1] = 0 ;
+    if (!parseline(line.s, line.len, &nu, la, &lp, ra, &rp, is6)) break ;
+#ifdef DEBUG
+    debuglog(lp, rp, nu, la, ra, is6) ;
+#endif
+    if ((lp == localport) && (rp == remoteport)
+     && !byte_diff(la, is6 ? 16 : 4, localaddr->ip)
+     && !byte_diff(ra, is6 ? 16 : 4, remoteaddr->ip))
+    {
+      u = nu ; break ;
+    }
+  }
+  stralloc_free(&line) ;
+ err:
+  fd_close(fd) ;
+  return u ;
+}