X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/410c8acf139e945dce28bbc0c8b17dcfd0815643..13a55605839046f6f42910de713f4a9b6c44dfd4:/peer.c diff --git a/peer.c b/peer.c index 83123d1c..50dec936 100644 --- a/peer.c +++ b/peer.c @@ -1,6 +1,6 @@ /* -*-c-*- * - * $Id: peer.c,v 1.1 2001/02/03 20:26:37 mdw Exp $ + * $Id$ * * Communication with the peer * @@ -26,14 +26,6 @@ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ -/*----- Revision history --------------------------------------------------* - * - * $Log: peer.c,v $ - * Revision 1.1 2001/02/03 20:26:37 mdw - * Initial checkin. - * - */ - /*----- Header files ------------------------------------------------------*/ #include "tripe.h" @@ -43,8 +35,94 @@ static peer *peers = 0; static sel_file sock; +/*----- Tunnel table ------------------------------------------------------*/ + +const tunnel_ops *tunnels[] = { +#ifdef TUN_LINUX + &tun_linux, +#endif +#ifdef TUN_BSD + &tun_bsd, +#endif +#ifdef TUN_UNET + &tun_unet, +#endif + &tun_slip, + 0 +}, *tun_default; + /*----- Main code ---------------------------------------------------------*/ +/* --- @p_pingtype@ --- * + * + * Arguments: @unsigned msg@ = message type + * + * Returns: String to describe the message. + */ + +static const char *p_pingtype(unsigned msg) +{ + switch (msg & MSG_TYPEMASK) { + case MISC_PING: + case MISC_PONG: + return "transport-ping"; + case MISC_EPING: + case MISC_EPONG: + return "encrypted-ping"; + default: + abort(); + } +} + +/* --- @p_ponged@ --- * + * + * Arguments: @peer *p@ = peer packet arrived from + * @unsigned msg@ = message type + * @buf *b@ = buffer containing payload + * + * Returns: --- + * + * Use: Processes a ping response. + */ + +static void p_ponged(peer *p, unsigned msg, buf *b) +{ + uint32 id; + const octet *magic; + ping *pg; + + IF_TRACING(T_PEER, { + trace(T_PEER, "peer: received %s reply from %s", + p_pingtype(msg), p->spec.name); + trace_block(T_PACKET, "peer: ping contents", BBASE(b), BSZ(b)); + }) + + if (buf_getu32(b, &id) || + (magic = buf_get(b, sizeof(pg->magic))) == 0 || + BLEFT(b)) { + a_warn("PEER", "?PEER", p, "malformed-%s", p_pingtype(msg), A_END); + return; + } + + for (pg = p->pings; pg; pg = pg->next) { + if (pg->id == id) + goto found; + } + a_warn("PEER", + "?PEER", p, + "unexpected-%s", p_pingtype(msg), + "0x%08lx", (unsigned long)id, + A_END); + return; + +found: + if (memcmp(magic, pg->magic, sizeof(pg->magic)) != 0) { + a_warn("PEER", "?PEER", p, "corrupt-%s", p_pingtype(msg), A_END); + return; + } + p_pingdone(pg, PING_OK); +} + /* --- @p_read@ --- * * * Arguments: @int fd@ = file descriptor to read from @@ -58,7 +136,7 @@ static sel_file sock; static void p_read(int fd, unsigned mode, void *v) { - peer *p; + peer *p = 0; addr a; size_t sz; ssize_t n; @@ -67,63 +145,140 @@ static void p_read(int fd, unsigned mode, void *v) /* --- Read the data --- */ + TIMER; sz = sizeof(addr); n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz); if (n < 0) { - a_warn("error reading socket: %s", strerror(errno)); + a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END); + return; + } + + /* --- If the packet is a greeting, don't check peers --- */ + + if (n && buf_i[0] == (MSG_MISC | MISC_GREET)) { + IF_TRACING(T_PEER, { + trace(T_PEER, "peer: greeting received from INET %s %u", + inet_ntoa(a.sin.sin_addr), + (unsigned)ntohs(a.sin.sin_port)); + trace_block(T_PACKET, "peer: greeting contents", buf_i, n); + }) + buf_init(&b, buf_i, n); + buf_getbyte(&b); + if (c_check(&b) || BLEFT(&b)) { + a_warn("PEER", "-", "invalid-greeting", A_END); + return; + } + a_notify("GREET", + "?B64", buf_i + 1, (size_t)(n - 1), + "?ADDR", &a, + A_END); return; } /* --- Find the appropriate peer --- */ assert(a.sa.sa_family == AF_INET); - T( trace(T_PEER, "packet from %s:%u", - inet_ntoa(a.sin.sin_addr), (unsigned)ntohs(a.sin.sin_port)); ) for (p = peers; p; p = p->next) { - T( trace(T_PEER, "trying %s:%u", - inet_ntoa(p->peer.sin.sin_addr), (unsigned)ntohs(p->peer.sin.sin_port)); ) - if (p->peer.sin.sin_addr.s_addr == a.sin.sin_addr.s_addr && - p->peer.sin.sin_port == a.sin.sin_port) + if (p->spec.sa.sin.sin_addr.s_addr == a.sin.sin_addr.s_addr && + p->spec.sa.sin.sin_port == a.sin.sin_port) goto found; } - a_warn("packet from unexpected peer: %s:%u", - inet_ntoa(a.sin.sin_addr), (unsigned)ntohs(a.sin.sin_port)); + a_warn("PEER", "-", "unexpected-source", "?ADDR", &a, A_END); return; found: - T( trace(T_PEER, "peer: packet received from `%s'", p->name); - trace_block(T_PACKET, "peer: packet contents", buf_i, n); ) + IF_TRACING(T_PEER, { + trace(T_PEER, "peer: packet received from `%s'", p->spec.name); + trace_block(T_PACKET, "peer: packet contents", buf_i, n); + }) /* --- Pick the packet apart --- */ + p->st.t_last = time(0); + p->st.n_in++; + p->st.sz_in += n; buf_init(&b, buf_i, n); if ((ch = buf_getbyte(&b)) < 0) { - a_warn("bad packet from `%s': no type byte", p->name); + a_warn("PEER", "?PEER", p, "bad-packet", "no-type", A_END); return; } - switch (ch) { + switch (ch & MSG_CATMASK) { case MSG_PACKET: + if (ch & MSG_TYPEMASK) { + a_warn("PEER", + "?PEER", p, + "bad-packet", + "unknown-type", "0x%02x", ch, + A_END); + p->st.n_reject++; + return; + } buf_init(&bb, buf_o, sizeof(buf_o)); - if (ks_decrypt(&p->ks, &b, &bb)) { - a_warn("couldn't decrypt inbound packet"); + if (ksl_decrypt(&p->ks, MSG_PACKET, &b, &bb)) { + p->st.n_reject++; + a_warn("PEER", "?PEER", p, "decrypt-failed", A_END); return; } - if (BOK(&bb)) - tun_inject(&p->t, &bb); - else - a_warn("packet build failed"); - break; - case MSG_PRECHALLENGE: - kx_prechallenge(&p->kx, &b); + if (BOK(&bb)) { + p->st.n_ipin++; + p->st.sz_ipin += BSZ(&b); + p->t->ops->inject(p->t, &bb); + } else { + p->st.n_reject++; + a_warn("PEER", "?PEER", p, "packet-build-failed", A_END); + } break; - case MSG_CHALLENGE: - kx_challenge(&p->kx, &b); + case MSG_KEYEXCH: + kx_message(&p->kx, ch & MSG_TYPEMASK, &b); break; - case MSG_RESPONSE: - kx_response(&p->kx, &b); + case MSG_MISC: + switch (ch & MSG_TYPEMASK) { + case MISC_NOP: + T( trace(T_PEER, "peer: received NOP packet"); ) + break; + case MISC_PING: + buf_put(p_txstart(p, MSG_MISC | MISC_PONG), BCUR(&b), BLEFT(&b)); + p_txend(p); + break; + case MISC_PONG: + p_ponged(p, MISC_PONG, &b); + break; + case MISC_EPING: + buf_init(&bb, buf_t, sizeof(buf_t)); + if (ksl_decrypt(&p->ks, ch, &b, &bb)) { + p->st.n_reject++; + a_warn("PEER", "?PEER", "decrypt-failed", A_END); + return; + } + if (BOK(&bb)) { + buf_flip(&bb); + if (ksl_encrypt(&p->ks, MSG_MISC | MISC_EPONG, &bb, + p_txstart(p, MSG_MISC | MISC_EPONG))) + kx_start(&p->kx, 0); + p_txend(p); + } + break; + case MISC_EPONG: + buf_init(&bb, buf_t, sizeof(buf_t)); + if (ksl_decrypt(&p->ks, ch, &b, &bb)) { + p->st.n_reject++; + a_warn("PEER", "?PEER", p, "decrypt-failed", A_END); + return; + } + if (BOK(&bb)) { + buf_flip(&bb); + p_ponged(p, MISC_EPONG, &bb); + } + break; + } break; default: - a_warn("bad packet from `%s': unknown packet type", p->name); + p->st.n_reject++; + a_warn("PEER", + "?PEER", p, + "bad-packet", + "unknown-category" "0x%02x", ch, + A_END); break; } } @@ -155,17 +310,171 @@ buf *p_txstart(peer *p, unsigned msg) * Use: Sends a packet to the peer. */ -void p_txend(peer *p) +static void p_setkatimer(peer *); + +static int p_dotxend(peer *p) { if (!BOK(&p->b)) { - a_warn("packet build failed"); - return; + a_warn("PEER", "?PEER", p, "packet-build-failed", A_END); + return (0); } IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet", BBASE(&p->b), BLEN(&p->b)); ) if (sendto(sock.fd, BBASE(&p->b), BLEN(&p->b), - 0, &p->peer.sa, p->sasz) < 0) - a_warn("packet send to `%s' failed: %s", p->name, strerror(errno)); + 0, &p->spec.sa.sa, p->spec.sasz) < 0) { + a_warn("PEER", "?PEER", p, "socket-write-error", "?ERRNO", A_END); + return (0); + } else { + p->st.n_out++; + p->st.sz_out += BLEN(&p->b); + return (1); + } +} + +void p_txend(peer *p) +{ + if (p_dotxend(p) && p->spec.t_ka) { + sel_rmtimer(&p->tka); + p_setkatimer(p); + } +} + +/* --- @p_pingwrite@ --- * + * + * Arguments: @ping *p@ = ping structure + * @buf *b@ = buffer to write in + * + * Returns: --- + * + * Use: Fills in a ping structure and writes the packet payload. + */ + +static void p_pingwrite(ping *p, buf *b) +{ + static uint32 seq = 0; + + p->id = U32(seq++); + GR_FILL(&rand_global, p->magic, sizeof(p->magic)); + buf_putu32(b, p->id); + buf_put(b, p->magic, sizeof(p->magic)); +} + +/* --- @p_pingdone@ --- * + * + * Arguments: @ping *p@ = ping structure + * @int rc@ = return code to pass on + * + * Returns: --- + * + * Use: Disposes of a ping structure, maybe sending a notification. + */ + +void p_pingdone(ping *p, int rc) +{ + if (p->prev) p->prev->next = p->next; + else p->p->pings = p->next; + if (p->next) p->next->prev = p->prev; + if (rc != PING_TIMEOUT) sel_rmtimer(&p->t); + T( trace(T_PEER, "peer: ping 0x%08lx done (rc = %d)", + (unsigned long)p->id, rc); ) + if (rc >= 0) p->func(rc, p->arg); +} + +/* --- @p_pingtimeout@ --- * + * + * Arguments: @struct timeval *now@ = the time now + * @void *pv@ = pointer to ping block + * + * Returns: --- + * + * Use: Called when a ping times out. + */ + +static void p_pingtimeout(struct timeval *now, void *pv) +{ + ping *p = pv; + + T( trace(T_PEER, "peer: ping 0x%08lx timed out", (unsigned long)p->id); ) + p_pingdone(p, PING_TIMEOUT); +} + +/* --- @p_pingsend@ --- * + * + * Arguments: @peer *p@ = destination peer + * @ping *pg@ = structure to fill in + * @unsigned type@ = message type + * @unsigned long timeout@ = how long to wait before giving up + * @void (*func)(int, void *)@ = callback function + * @void *arg@ = argument for callback + * + * Returns: Zero if successful, nonzero if it failed. + * + * Use: Sends a ping to a peer. Call @func@ with a nonzero argument + * if we get an answer within the timeout, or zero if no answer. + */ + +int p_pingsend(peer *p, ping *pg, unsigned type, + unsigned long timeout, + void (*func)(int, void *), void *arg) +{ + buf *b, bb; + struct timeval tv; + + switch (type) { + case MISC_PING: + pg->msg = MISC_PONG; + b = p_txstart(p, MSG_MISC | MISC_PING); + p_pingwrite(pg, b); + p_txend(p); + break; + case MISC_EPING: + pg->msg = MISC_EPONG; + b = p_txstart(p, MSG_MISC | MISC_EPING); + buf_init(&bb, buf_t, sizeof(buf_t)); + p_pingwrite(pg, &bb); + buf_flip(&bb); + if (ksl_encrypt(&p->ks, MSG_MISC | MISC_EPING, &bb, b)) + kx_start(&p->kx, 0); + if (!BOK(b)) + return (-1); + p_txend(p); + break; + default: + abort(); + break; + } + + pg->next = p->pings; + pg->prev = 0; + pg->p = p; + pg->func = func; + pg->arg = arg; + if (p->pings) p->pings->prev = pg; + p->pings = pg; + gettimeofday(&tv, 0); + tv.tv_sec += timeout; + sel_addtimer(&sel, &pg->t, &tv, p_pingtimeout, pg); + T( trace(T_PEER, "peer: send %s 0x%08lx to %s", + p_pingtype(type), (unsigned long)pg->id, p->spec.name); ) + return (0); +} + +/* --- @p_greet@ --- * + * + * Arguments: @peer *p@ = peer to send to + * @const void *c@ = pointer to challenge + * @size_t sz@ = size of challenge + * + * Returns: --- + * + * Use: Sends a greeting packet. + */ + +void p_greet(peer *p, const void *c, size_t sz) +{ + buf *b = p_txstart(p, MSG_MISC | MISC_GREET); + buf_put(b, c, sz); + p_txend(p); } /* --- @p_tun@ --- * @@ -181,10 +490,34 @@ void p_txend(peer *p) void p_tun(peer *p, buf *b) { buf *bb = p_txstart(p, MSG_PACKET); - if (ks_encrypt(&p->ks, b, bb)) - kx_start(&p->kx); - if (BCUR(bb) > BBASE(bb)) + + TIMER; + if (ksl_encrypt(&p->ks, MSG_PACKET, b, bb)) + kx_start(&p->kx, 0); + if (BOK(bb) && BLEN(bb)) { + p->st.n_ipout++; + p->st.sz_ipout += BLEN(bb); p_txend(p); + } +} + +/* --- @p_keyreload@ --- * + * + * Arguments: --- + * + * Returns: --- + * + * Use: Forces a check of the daemon's keyring files. + */ + +void p_keyreload(void) +{ + peer *p; + + if (km_reload()) { + for (p = peers; p; p = p->next) + kx_newkeys(&p->kx); + } } /* --- @p_interval@ --- * @@ -198,18 +531,22 @@ void p_tun(peer *p, buf *b) void p_interval(void) { - peer *p, *pp; - int reload; + peer *p; - reload = km_interval(); - for (p = peers; p; p = pp) { - pp = p->next; - if (reload) - kx_newkeys(&p->kx); - ks_prune(&p->ks); - } + p_keyreload(); + for (p = peers; p; p = p->next) + ksl_prune(&p->ks); } +/* --- @p_stats@ --- * + * + * Arguments: @peer *p@ = pointer to a peer block + * + * Returns: A pointer to the peer's statistics. + */ + +stats *p_stats(peer *p) { return (&p->st); } + /* --- @p_ifname@ --- * * * Arguments: @peer *p@ = pointer to a peer block @@ -217,7 +554,7 @@ void p_interval(void) * Returns: A pointer to the peer's interface name. */ -const char *p_ifname(peer *p) { return (tun_ifname(&p->t)); } +const char *p_ifname(peer *p) { return (p->t->ops->ifname(p->t)); } /* --- @p_addr@ --- * * @@ -226,30 +563,46 @@ const char *p_ifname(peer *p) { return (tun_ifname(&p->t)); } * Returns: A pointer to the peer's address. */ -const addr *p_addr(peer *p) { return (&p->peer); } +const addr *p_addr(peer *p) { return (&p->spec.sa); } /* --- @p_init@ --- * * - * Arguments: @unsigned port@ = port number to listen to + * Arguments: @struct in_addr addr@ = address to bind to + * @unsigned port@ = port number to listen to * * Returns: --- * * Use: Initializes the peer system; creates the socket. */ -void p_init(unsigned port) +void p_init(struct in_addr addr, unsigned port) { int fd; struct sockaddr_in sin; + int len = PKBUFSZ; + + /* --- Note on socket buffer sizes --- * + * + * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer + * sizes I pass to @setsockopt@. I'm not putting special-case code here + * for Linux: BSD (at least TCPv2) does what I tell it rather than second- + * guessing me. + */ if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno)); BURN(sin); sin.sin_family = AF_INET; - sin.sin_addr.s_addr = INADDR_ANY; + sin.sin_addr = addr; sin.sin_port = htons(port); if (bind(fd, (struct sockaddr *)&sin, sizeof(sin))) die(EXIT_FAILURE, "bind failed: %s", strerror(errno)); + if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) || + setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) { + die(EXIT_FAILURE, "failed to set socket buffer sizes: %s", + strerror(errno)); + } + fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); sel_initfile(&sel, &sock, fd, SEL_READ, p_read, 0); sel_addfile(&sock); T( trace(T_PEER, "peer: created socket"); ) @@ -273,11 +626,47 @@ unsigned p_port(void) return (ntohs(a.sin.sin_port)); } +/* --- @p_keepalive@ --- * + * + * Arguments: @struct timeval *now@ = the current time + * @void *pv@ = peer to wake up + * + * Returns: --- + * + * Use: Sends a keepalive ping message to its peer. + */ + +static void p_keepalive(struct timeval *now, void *pv) +{ + peer *p = pv; + p_txstart(p, MSG_MISC | MISC_NOP); p_dotxend(p); + T( trace(T_PEER, "peer: sent keepalive to %s", p->spec.name); ) + p_setkatimer(p); +} + +/* --- @p_setkatimer@ --- * + * + * Arguments: @peer *p@ = peer to set + * + * Returns: --- + * + * Use: Resets the keepalive timer thing. + */ + +static void p_setkatimer(peer *p) +{ + struct timeval tv; + + if (!p->spec.t_ka) + return; + gettimeofday(&tv, 0); + tv.tv_sec += p->spec.t_ka; + sel_addtimer(&sel, &p->tka, &tv, p_keepalive, p); +} + /* --- @p_create@ --- * * - * Arguments: @const char *name@ = name for this peer - * @struct sockaddr *sa@ = socket address of peer - * @size_t sz@ = size of socket address + * Arguments: @peerspec *spec@ = information about this peer * * Returns: Pointer to the peer block, or null if it failed. * @@ -285,29 +674,42 @@ unsigned p_port(void) * by this point. */ -peer *p_create(const char *name, struct sockaddr *sa, size_t sz) +peer *p_create(peerspec *spec) { peer *p = CREATE(peer); - T( trace(T_PEER, "peer: creating new peer `%s'", name); ) - p->name = xstrdup(name); + + T( trace(T_PEER, "peer: creating new peer `%s'", spec->name); ) + p->spec = *spec; + p->spec.name = xstrdup(spec->name); p->ks = 0; p->prev = 0; - memcpy(&p->peer.sa, sa, sz); - p->sasz = sz; - if (kx_init(&p->kx, p, &p->ks)) + p->pings = 0; + memset(&p->st, 0, sizeof(stats)); + p->st.t_start = time(0); + if ((p->t = spec->tops->create(p)) == 0) goto tidy_0; - if (tun_create(&p->t, p)) + p_setkatimer(p); + if (kx_init(&p->kx, p, &p->ks)) goto tidy_1; p->next = peers; if (peers) peers->prev = p; peers = p; + a_notify("ADD", + "?PEER", p, + "%s", p->t->ops->ifname(p->t), + "?ADDR", &p->spec.sa, + A_END); + a_notify("KXSTART", "?PEER", p, A_END); + /* Couldn't tell anyone before */ return (p); tidy_1: - kx_free(&p->kx); + if (spec->t_ka) + sel_rmtimer(&p->tka); + p->t->ops->destroy(p->t); tidy_0: - xfree(p->name); + xfree(p->spec.name); DESTROY(p); return (0); } @@ -319,7 +721,16 @@ tidy_0: * Returns: A pointer to the peer's name. */ -const char *p_name(peer *p) { return (p->name); } +const char *p_name(peer *p) { return (p->spec.name); } + +/* --- @p_spec@ --- * + * + * Arguments: @peer *p@ = pointer to a peer block + * + * Returns: Pointer to the peer's specification + */ + +const peerspec *p_spec(peer *p) { return (&p->spec); } /* --- @p_find@ --- * * @@ -334,7 +745,7 @@ peer *p_find(const char *name) { peer *p; for (p = peers; p; p = p->next) { - if (strcmp(name, p->name) == 0) + if (strcmp(name, p->spec.name) == 0) return (p); } return (0); @@ -351,11 +762,20 @@ peer *p_find(const char *name) void p_destroy(peer *p) { - T( trace(T_PEER, "peer: destroying peer `%s'", p->name); ) - ks_free(&p->ks); + ping *pg, *ppg; + + T( trace(T_PEER, "peer: destroying peer `%s'", p->spec.name); ) + a_notify("KILL", "%s", p->spec.name, A_END); + ksl_free(&p->ks); kx_free(&p->kx); - tun_destroy(&p->t); - xfree(p->name); + p->t->ops->destroy(p->t); + if (p->spec.t_ka) + sel_rmtimer(&p->tka); + xfree(p->spec.name); + for (pg = p->pings; pg; pg = ppg) { + ppg = pg->next; + p_pingdone(pg, PING_PEERDIED); + } if (p->next) p->next->prev = p->prev; if (p->prev)