diff options
Diffstat (limited to 'src/minidentd/mgetuid-linux.c')
| -rw-r--r-- | src/minidentd/mgetuid-linux.c | 169 |
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 ; +} |