diff options
Diffstat (limited to 'src/skadns/skadnsd.c')
| -rw-r--r-- | src/skadns/skadnsd.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/src/skadns/skadnsd.c b/src/skadns/skadnsd.c new file mode 100644 index 0000000..7b5419f --- /dev/null +++ b/src/skadns/skadnsd.c @@ -0,0 +1,199 @@ +/* ISC license. */ + +#include <errno.h> +#include <signal.h> +#include <skalibs/uint16.h> +#include <skalibs/error.h> +#include <skalibs/strerr2.h> +#include <skalibs/sig.h> +#include <skalibs/tai.h> +#include <skalibs/djbunix.h> +#include <skalibs/iopause.h> +#include <skalibs/unixmessage.h> +#include <skalibs/skaclient.h> +#include <s6-dns/s6dns.h> +#include <s6-dns/skadns.h> + +typedef struct dnsio_s dnsio_t, *dnsio_t_ref ; +struct dnsio_s +{ + unsigned int xindex ; + s6dns_engine_t dt ; + uint16 id ; +} ; +#define DNSIO_ZERO { .xindex = SKADNS_MAXCONCURRENCY, .dt = S6DNS_ENGINE_ZERO, .id = 0 } + +static dnsio_t a[SKADNS_MAXCONCURRENCY] ; +static unsigned int sp = 0 ; + +static void remove (unsigned int i) +{ + dnsio_t tmp ; + tmp = a[sp-1] ; + a[--sp] = a[i] ; + a[i] = tmp ; +} + +static void fail (unsigned int i) +{ + char pack[3] ; + unixmessage_t m = { .s = pack, len = 3, .fds = 0, .nfds = 0 } ; + uint16_pack_big(pack, a[i].id) ; + pack[2] = a[i].dt.status ; + s6dns_engine_recycle(&a[i].dt) ; + remove(i) ; + if (!unixmessage_put(unixmessage_sender_x, &m)) + strerr_diefu1sys(111, "unixmessage_put") ; +} + +static void answer (char c) +{ + unixmessage_t m = { .s = &c, .len = 1, .fds = 0, .nfds = 0 } ; + if (!unixmessage_put(unixmessage_sender_1, &m)) + strerr_diefu1sys(111, "unixmessage_put") ; +} + +static int parse_protocol (unixmessage_t const *m, void *context) +{ + uint16 id ; + if (m->len < 3 || m->nfds) strerr_dief1x(100, "invalid client request") ; + uint16_unpack_big(m->s, &id) ; + switch (m->s[2]) /* protocol parsing */ + { + case 'Q' : /* send a query */ + { + tain_t limit ; + uint16 qtype ; + if (m->len < 21) strerr_dief1x(100, "invalid client request") ; + if (sp >= SKADNS_MAXCONCURRENCY) + { + answer(ENFILE) ; + break ; + } + uint16_unpack_big(m->s + 3, &qtype) ; + if (byte_diff(m->s + 5, 12, "\0\0\0\0\0\0\0\0\0\0\0")) + tain_unpack(m->s + 5, &limit) ; + else tain_add_g(&limit, &tain_infinite_relative) ; + if (!s6dns_engine_init_g(&a[sp].dt, &s6dns_rci_here.servers, 1, m->s + 17, m->len - 17, qtype, &limit)) + { + answer(errno) ; + break ; + } + a[sp++].id = id ; + answer(0) ; + break ; + } + case 'q' : /* cancel a query */ + { + register unsigned int i = 0 ; + for (; i < sp ; i++) if (a[i].id == id) break ; + if (i >= sp) + { + answer(ENOENT) ; + break ; + } + s6dns_engine_recycle(&a[i].dt) ; + remove(i) ; + answer(0) ; + break ; + } + default : strerr_dief1x(100, "invalid client request") ; + } + (void)context ; + return 1 ; +} + +int main (void) +{ + PROG = "skadnsd" ; + + if (ndelay_on(0) < 0) strerr_diefu2sys(111, "ndelay_on ", "0") ; + if (ndelay_on(1) < 0) strerr_diefu2sys(111, "ndelay_on ", "1") ; + if (sig_ignore(SIGPIPE) < 0) strerr_diefu1sys(111, "ignore SIGPIPE") ; + tain_now_g() ; + if (!s6dns_init()) strerr_diefu1sys(111, "s6dns_init") ; + + { + tain_t deadline ; + tain_addsec_g(&deadline, 2) ; + if (!skaclient_server_01x_init_g(SKADNS_BANNER1, SKADNS_BANNER1_LEN, SKADNS_BANNER2, SKADNS_BANNER2_LEN, &deadline)) + strerr_diefu1sys(111, "sync with client") ; + } + { + static dnsio_t const zero = DNSIO_ZERO ; + register unsigned int i = 0 ; + for (; i < SKADNS_MAXCONCURRENCY ; i++) a[i] = zero ; + } + + for (;;) + { + iopause_fd x[3 + sp] ; + register int r ; + + x[0].fd = 0 ; x[0].events = IOPAUSE_EXCEPT | IOPAUSE_READ ; + x[1].fd = 1 ; x[1].events = IOPAUSE_EXCEPT | (unixmessage_sender_isempty(unixmessage_sender_1) ? 0 : IOPAUSE_WRITE) ; + x[2].fd = unixmessage_sender_fd(unixmessage_sender_x) ; + x[2].events = IOPAUSE_EXCEPT | (unixmessage_sender_isempty(unixmessage_sender_x) ? 0 : IOPAUSE_WRITE) ; + { + tain_t deadline = TAIN_INFINITE ; + register unsigned int i = 0 ; + for (; i < sp ; i++) + { + register unsigned int j = 3 + i ; + s6dns_engine_nextdeadline(&a[i].dt, &deadline) ; + x[j].fd = a[i].dt.fd ; + x[j].events = 0 ; + if (s6dns_engine_isreadable(&a[i].dt)) x[j].events |= IOPAUSE_READ ; + if (s6dns_engine_iswritable(&a[i].dt)) x[j].events |= IOPAUSE_WRITE ; + a[i].xindex = j ; + } + r = iopause_g(x, 3 + sp, &deadline) ; + } + if (r < 0) strerr_diefu1sys(111, "iopause") ; + if (!r) + { + register unsigned int i = 0 ; + for (; i < sp ; i++) + if (s6dns_engine_timeout_g(&a[i].dt)) fail(i--) ; + continue ; + } + + if (x[1].revents & IOPAUSE_WRITE) + if ((unixmessage_sender_flush(unixmessage_sender_1) < 0) && !error_isagain(errno)) + strerr_diefu1sys(111, "flush stdout") ; + if (x[2].revents & IOPAUSE_WRITE) + if ((unixmessage_sender_flush(unixmessage_sender_x) < 0) && !error_isagain(errno)) + strerr_diefu1sys(111, "flush asyncout") ; + + { + register unsigned int i = 0 ; + for (; i < sp ; i++) if (x[a[i].xindex].revents) + { + register int r = s6dns_engine_event_g(&a[i].dt) ; + if (r < 0) fail(i--) ; + else if (r) + { + char pack[3] ; + siovec_t v[2] = { { .s = pack, .len = 3 }, { .s = s6dns_engine_packet(&a[i].dt), .len = s6dns_engine_packetlen(&a[i].dt) } } ; + unixmessage_v_t mv = { .v = v, .vlen = 2, .fds = 0, .nfds = 0 } ; + uint16_pack_big(pack, a[i].id) ; + pack[2] = 0 ; + if (!unixmessage_putv(unixmessage_sender_x, v, 2)) + strerr_diefu1sys(111, "unixmessage_put") ; + s6dns_engine_recycle(&a[i].dt) ; + remove(i--) ; + } + } + } + + if (!unixmessage_receiver_isempty(unixmessage_receiver_0) || x[0].revents & IOPAUSE_READ) + { + if (unixmessage_handle(unixmessage_receiver_0, &parse_protocol, 0) < 0) + { + if (errno == EPIPE) break ; /* normal exit */ + strerr_diefu1sys(111, "handle messages from client") ; + } + } + } + return 0 ; +} |