diff --git a/conf.c b/conf.c index 3aa3314..e2a7d68 100644 --- a/conf.c +++ b/conf.c @@ -775,7 +775,15 @@ static void usage(const char *name) info( " -g, --gateway ADDR Pass IPv4 or IPv6 address as gateway"); info( " default: gateway from interface with default route"); info( " -i, --interface NAME Interface for addresses and routes"); - info( " default: interface with first default route"); + info( " default: from --outbound-if4 and --outbound-if6, if any"); + info( " otherwise interface with first default route"); + info( " -o, --outbound ADDR Bind to address as outbound source"); + info( " can be specified zero to two times (for IPv4 and IPv6)"); + info( " default: use source address from routing tables"); + info( " --outbound-if4 NAME Bind to outbound interface for IPv4"); + info( " default: use interface from default route"); + info( " --outbound-if6 NAME Bind to outbound interface for IPv6"); + info( " default: use interface from default route"); info( " -D, --dns ADDR Use IPv4 or IPv6 address as DNS"); info( " can be specified multiple times"); info( " a single, empty option disables DNS information"); @@ -900,7 +908,7 @@ pasta_opts: */ static void conf_print(const struct ctx *c) { - char buf4[INET_ADDRSTRLEN], ifn[IFNAMSIZ]; + char buf4[INET_ADDRSTRLEN], buf6[INET6_ADDRSTRLEN], ifn[IFNAMSIZ]; int i; info("Template interface: %s%s%s%s%s", @@ -910,6 +918,26 @@ static void conf_print(const struct ctx *c) c->ifi6 ? if_indextoname(c->ifi6, ifn) : "", c->ifi6 ? " (IPv6)" : ""); + if (*c->ip4.ifname_out || *c->ip6.ifname_out) { + info("Outbound interface: %s%s%s%s%s", + *c->ip4.ifname_out ? c->ip4.ifname_out : "", + *c->ip4.ifname_out ? " (IPv4)" : "", + (*c->ip4.ifname_out && *c->ip6.ifname_out) ? ", " : "", + *c->ip6.ifname_out ? c->ip6.ifname_out : "", + *c->ip6.ifname_out ? " (IPv6)" : ""); + } + + if (!IN4_IS_ADDR_UNSPECIFIED(&c->ip4.addr_out) || + !IN6_IS_ADDR_UNSPECIFIED(&c->ip6.addr_out)) { + info("Outbound address: %s%s%s", + IN4_IS_ADDR_UNSPECIFIED(&c->ip4.addr_out) ? "" : + inet_ntop(AF_INET, &c->ip4.addr_out, buf4, sizeof(buf4)), + (!IN4_IS_ADDR_UNSPECIFIED(&c->ip4.addr_out) && + !IN6_IS_ADDR_UNSPECIFIED(&c->ip6.addr_out)) ? ", " : "", + IN6_IS_ADDR_UNSPECIFIED(&c->ip6.addr_out) ? "" : + inet_ntop(AF_INET6, &c->ip6.addr_out, buf6, sizeof(buf6))); + } + if (c->mode == MODE_PASTA) info("Namespace interface: %s", c->pasta_ifn); @@ -948,8 +976,6 @@ static void conf_print(const struct ctx *c) } if (c->ifi6) { - char buf6[INET6_ADDRSTRLEN]; - if (!c->no_ndp && !c->no_dhcpv6) info("NDP/DHCPv6:"); else if (!c->no_ndp) @@ -1125,6 +1151,7 @@ void conf(struct ctx *c, int argc, char **argv) {"mac-addr", required_argument, NULL, 'M' }, {"gateway", required_argument, NULL, 'g' }, {"interface", required_argument, NULL, 'i' }, + {"outbound", required_argument, NULL, 'o' }, {"dns", required_argument, NULL, 'D' }, {"search", required_argument, NULL, 'S' }, {"no-tcp", no_argument, &c->no_tcp, 1 }, @@ -1157,6 +1184,8 @@ void conf(struct ctx *c, int argc, char **argv) {"runas", required_argument, NULL, 12 }, {"log-size", required_argument, NULL, 13 }, {"version", no_argument, NULL, 14 }, + {"outbound-if4", required_argument, NULL, 15 }, + {"outbound-if6", required_argument, NULL, 16 }, { 0 }, }; struct get_bound_ports_ns_arg ns_ports_arg = { .c = c }; @@ -1166,8 +1195,8 @@ void conf(struct ctx *c, int argc, char **argv) struct in6_addr *dns6 = c->ip6.dns; struct fqdn *dnss = c->dns_search; struct in_addr *dns4 = c->ip4.dns; + unsigned int ifi4 = 0, ifi6 = 0; const char *optstring; - unsigned int ifi = 0; int name, ret, b, i; size_t logsize = 0; uid_t uid; @@ -1175,9 +1204,9 @@ void conf(struct ctx *c, int argc, char **argv) if (c->mode == MODE_PASTA) { c->no_dhcp_dns = c->no_dhcp_dns_search = 1; - optstring = "dqfel:hF:I:p:P:m:a:n:M:g:i:D:S:46t:u:T:U:"; + optstring = "dqfel:hF:I:p:P:m:a:n:M:g:i:o:D:S:46t:u:T:U:"; } else { - optstring = "dqfel:hs:F:p:P:m:a:n:M:g:i:D:S:461t:u:"; + optstring = "dqfel:hs:F:p:P:m:a:n:M:g:i:o:D:S:461t:u:"; } c->tcp.fwd_in.mode = c->tcp.fwd_out.mode = 0; @@ -1295,6 +1324,26 @@ void conf(struct ctx *c, int argc, char **argv) c->mode == MODE_PASST ? "passt " : "pasta "); fprintf(stdout, VERSION_BLOB); exit(EXIT_SUCCESS); + case 15: + if (*c->ip4.ifname_out) + die("Redundant outbound interface: %s", optarg); + + ret = snprintf(c->ip4.ifname_out, + sizeof(c->ip4.ifname_out), "%s", optarg); + if (ret <= 0 || ret >= (int)sizeof(c->ip4.ifname_out)) + die("Invalid interface name: %s", optarg); + + break; + case 16: + if (*c->ip6.ifname_out) + die("Redundant outbound interface: %s", optarg); + + ret = snprintf(c->ip6.ifname_out, + sizeof(c->ip6.ifname_out), "%s", optarg); + if (ret <= 0 || ret >= (int)sizeof(c->ip6.ifname_out)) + die("Invalid interface name: %s", optarg); + + break; case 'd': if (c->debug) die("Multiple --debug options given"); @@ -1459,13 +1508,33 @@ void conf(struct ctx *c, int argc, char **argv) die("Invalid gateway address: %s", optarg); break; case 'i': - if (ifi) + if (ifi4 || ifi6) die("Redundant interface: %s", optarg); - if (!(ifi = if_nametoindex(optarg))) + if (!(ifi4 = ifi6 = if_nametoindex(optarg))) die("Invalid interface name %s: %s", optarg, strerror(errno)); break; + case 'o': + if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.addr_out) && + inet_pton(AF_INET6, optarg, &c->ip6.addr_out) && + !IN6_IS_ADDR_UNSPECIFIED(&c->ip6.addr_out) && + !IN6_IS_ADDR_LOOPBACK(&c->ip6.addr_out) && + !IN6_IS_ADDR_V4MAPPED(&c->ip6.addr_out) && + !IN6_IS_ADDR_V4COMPAT(&c->ip6.addr_out) && + !IN6_IS_ADDR_MULTICAST(&c->ip6.addr_out)) + break; + + if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.addr_out) && + inet_pton(AF_INET, optarg, &c->ip4.addr_out) && + !IN4_IS_ADDR_UNSPECIFIED(&c->ip4.addr_out) && + !IN4_IS_ADDR_BROADCAST(&c->ip4.addr_out) && + !IN4_IS_ADDR_MULTICAST(&c->ip4.addr_out)) + break; + + die("Invalid or redundant outbound address: %s", + optarg); + break; case 'D': if (!strcmp(optarg, "none")) { if (c->no_dns) @@ -1557,6 +1626,12 @@ void conf(struct ctx *c, int argc, char **argv) if (*c->sock_path && c->fd_tap >= 0) die("Options --socket and --fd are mutually exclusive"); + if (!ifi4 && *c->ip4.ifname_out) + ifi4 = if_nametoindex(c->ip4.ifname_out); + + if (!ifi6 && *c->ip6.ifname_out) + ifi6 = if_nametoindex(c->ip6.ifname_out); + conf_ugid(runas, &uid, &gid); if (logfile) { @@ -1566,10 +1641,12 @@ void conf(struct ctx *c, int argc, char **argv) nl_sock_init(c, false); if (!v6_only) - c->ifi4 = conf_ip4(ifi, &c->ip4, c->mac); + c->ifi4 = conf_ip4(ifi4, &c->ip4, c->mac); if (!v4_only) - c->ifi6 = conf_ip6(ifi, &c->ip6, c->mac); - if (!c->ifi4 && !c->ifi6) + c->ifi6 = conf_ip6(ifi6, &c->ip6, c->mac); + if ((!c->ifi4 && !c->ifi6) || + (*c->ip4.ifname_out && !c->ifi4) || + (*c->ip6.ifname_out && !c->ifi6)) die("External interface not usable"); /* Inbound port options can be parsed now (after IPv4/IPv6 settings) */ diff --git a/icmp.c b/icmp.c index b842fa8..ddf83f8 100644 --- a/icmp.c +++ b/icmp.c @@ -170,8 +170,16 @@ int icmp_tap_handler(const struct ctx *c, int af, const void *addr, iref.icmp.id = id = ntohs(ih->un.echo.id); if ((s = icmp_id_map[V4][id].sock) <= 0) { - s = sock_l4(c, AF_INET, IPPROTO_ICMP, NULL, NULL, id, - iref.u32); + const struct in_addr *bind_addr = NULL; + const char *bind_if; + + bind_if = *c->ip4.ifname_out ? c->ip4.ifname_out : NULL; + + if (!IN4_IS_ADDR_UNSPECIFIED(&c->ip4.addr_out)) + bind_addr = &c->ip4.addr_out; + + s = sock_l4(c, AF_INET, IPPROTO_ICMP, bind_addr, + bind_if, id, iref.u32); if (s < 0) goto fail_sock; if (s > SOCKET_MAX) { @@ -216,8 +224,16 @@ int icmp_tap_handler(const struct ctx *c, int af, const void *addr, iref.icmp.id = id = ntohs(ih->icmp6_identifier); if ((s = icmp_id_map[V6][id].sock) <= 0) { - s = sock_l4(c, AF_INET6, IPPROTO_ICMPV6, NULL, NULL, id, - iref.u32); + const struct in6_addr *bind_addr = NULL; + const char *bind_if; + + bind_if = *c->ip6.ifname_out ? c->ip6.ifname_out : NULL; + + if (!IN6_IS_ADDR_UNSPECIFIED(&c->ip6.addr_out)) + bind_addr = &c->ip6.addr_out; + + s = sock_l4(c, AF_INET6, IPPROTO_ICMPV6, bind_addr, + bind_if, id, iref.u32); if (s < 0) goto fail_sock; if (s > SOCKET_MAX) { diff --git a/passt.1 b/passt.1 index f317c33..6136fa5 100644 --- a/passt.1 +++ b/passt.1 @@ -180,8 +180,33 @@ to allow mapping of local traffic to guest and target namespace. See the .TP .BR \-i ", " \-\-interface " " \fIname Use host interface \fIname\fR to derive addresses and routes. -Default is to use the interfaces with the first default routes for each IP -version. +Default is to use the interfaces specified by \fB--outbound-if4\fR and +\fB--outbound-if6\fR, for IPv4 and IPv6 addresses and routes, respectively. If +no interfaces are given, the interface with the first default routes for each IP +version is selected. + +.TP +.BR \-o ", " \-\-outbound " " \fIaddr +Use an IPv4 \fIaddr\fR as source address for IPv4 outbound TCP connections, UDP +flows, ICMP requests, or an IPv6 \fIaddr\fR for IPv6 ones, by binding outbound +sockets to it. +This option can be specified zero (for defaults) to two times (once for IPv4, +once for IPv6). +By default, the source address is selected by the routing tables. + +.TP +.BR \-\-outbound-if4 " " \fIname +Bind IPv4 outbound sockets to host interface \fIname\fR, and, unless another +interface is specified via \fB-i\fR, \fB--interface\fR, use this interface to +derive IPv4 addresses and routes. +By default, the interface given by the default route is selected. + +.TP +.BR \-\-outbound-if6 " " \fIname +Bind IPv6 outbound sockets to host interface \fIname\fR, and, unless another +interface is specified via \fB-i\fR, \fB--interface\fR, use this interface to +derive IPv6 addresses and routes. +By default, the interface given by the default route is selected. .TP .BR \-D ", " \-\-dns " " \fIaddr diff --git a/passt.h b/passt.h index cc60c84..b73f4ff 100644 --- a/passt.h +++ b/passt.h @@ -106,6 +106,8 @@ enum passt_modes { * @dns: DNS addresses for DHCP, zero-terminated, network order * @dns_match: Forward DNS query if sent to this address, network order * @dns_host: Use this DNS on the host for forwarding, network order + * @addr_out: Optional source address for outbound traffic + * @ifname_out: Optional interface name to bind outbound sockets to */ struct ip4_ctx { struct in_addr addr; @@ -115,6 +117,9 @@ struct ip4_ctx { struct in_addr dns[MAXNS + 1]; struct in_addr dns_match; struct in_addr dns_host; + + struct in_addr addr_out; + char ifname_out[IFNAMSIZ]; }; /** @@ -127,6 +132,8 @@ struct ip4_ctx { * @dns: DNS addresses for DHCPv6 and NDP, zero-terminated * @dns_match: Forward DNS query if sent to this address * @dns_host: Use this DNS on the host for forwarding + * @addr_out: Optional source address for outbound traffic + * @ifname_out: Optional interface name to bind outbound sockets to */ struct ip6_ctx { struct in6_addr addr; @@ -137,6 +144,9 @@ struct ip6_ctx { struct in6_addr dns[MAXNS + 1]; struct in6_addr dns_match; struct in6_addr dns_host; + + struct in6_addr addr_out; + char ifname_out[IFNAMSIZ]; }; #include diff --git a/tcp.c b/tcp.c index b674311..8e8d653 100644 --- a/tcp.c +++ b/tcp.c @@ -1946,6 +1946,61 @@ static uint16_t tcp_conn_tap_mss(const struct ctx *c, return MIN(mss, USHRT_MAX); } +/** + * tcp_bind_outbound() - Bind socket to outbound address and interface if given + * @c: Execution context + * @s: Outbound TCP socket + * @af: Address family + */ +static void tcp_bind_outbound(const struct ctx *c, int s, sa_family_t af) +{ + if (af == AF_INET) { + if (!IN4_IS_ADDR_UNSPECIFIED(&c->ip4.addr_out)) { + struct sockaddr_in addr4 = { + .sin_family = AF_INET, + .sin_port = 0, + .sin_addr = c->ip4.addr_out, + }; + + if (bind(s, (struct sockaddr *)&addr4, sizeof(addr4))) { + debug("Can't bind IPv4 TCP socket address: %s", + strerror(errno)); + } + } + + if (*c->ip4.ifname_out) { + if (setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, + c->ip4.ifname_out, + strlen(c->ip4.ifname_out))) { + debug("Can't bind IPv4 TCP socket to interface:" + " %s", strerror(errno)); + } + } + } else if (af == AF_INET6) { + if (!IN6_IS_ADDR_UNSPECIFIED(&c->ip6.addr_out)) { + struct sockaddr_in6 addr6 = { + .sin6_family = AF_INET6, + .sin6_port = 0, + .sin6_addr = c->ip6.addr_out, + }; + + if (bind(s, (struct sockaddr *)&addr6, sizeof(addr6))) { + debug("Can't bind IPv6 TCP socket address: %s", + strerror(errno)); + } + } + + if (*c->ip6.ifname_out) { + if (setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, + c->ip6.ifname_out, + strlen(c->ip6.ifname_out))) { + debug("Can't bind IPv6 TCP socket to interface:" + " %s", strerror(errno)); + } + } + } +} + /** * tcp_conn_from_tap() - Handle connection request (SYN segment) from tap * @c: Execution context @@ -2052,6 +2107,11 @@ static void tcp_conn_from_tap(struct ctx *c, int af, const void *addr, if (errno != EADDRNOTAVAIL && errno != EACCES) conn_flag(c, conn, LOCAL); + if ((af == AF_INET && !IN4_IS_ADDR_LOOPBACK(&addr4.sin_addr)) || + (af == AF_INET6 && !IN6_IS_ADDR_LOOPBACK(&addr6.sin6_addr) && + !IN6_IS_ADDR_LINKLOCAL(&addr6.sin6_addr))) + tcp_bind_outbound(c, s, af); + if (connect(s, sa, sl)) { if (errno != EINPROGRESS) { tcp_rst(c, conn); diff --git a/udp.c b/udp.c index b7cbfdc..ef486fe 100644 --- a/udp.c +++ b/udp.c @@ -843,20 +843,6 @@ int udp_tap_handler(struct ctx *c, int af, const void *addr, sa = (struct sockaddr *)&s_in; sl = sizeof(s_in); - if (!(s = udp_tap_map[V4][src].sock)) { - union udp_epoll_ref uref = { .udp.port = src }; - - s = sock_l4(c, AF_INET, IPPROTO_UDP, NULL, NULL, src, - uref.u32); - if (s < 0) - return p->count; - - udp_tap_map[V4][src].sock = s; - bitmap_set(udp_act[V4][UDP_ACT_TAP], src); - } - - udp_tap_map[V4][src].ts = now->tv_sec; - if (IN4_ARE_ADDR_EQUAL(&s_in.sin_addr, &c->ip4.dns_match) && ntohs(s_in.sin_port) == 53) { s_in.sin_addr = c->ip4.dns_host; @@ -868,13 +854,37 @@ int udp_tap_handler(struct ctx *c, int af, const void *addr, else s_in.sin_addr = c->ip4.addr_seen; } + + if (!(s = udp_tap_map[V4][src].sock)) { + union udp_epoll_ref uref = { .udp.port = src }; + in_addr_t bind_addr = { 0 }; + const char *bind_if = NULL; + + if (!IN6_IS_ADDR_LOOPBACK(&s_in.sin_addr) && + *c->ip6.ifname_out) + bind_if = c->ip6.ifname_out; + + if (!IN4_IS_ADDR_UNSPECIFIED(&c->ip4.addr_out) && + !IN4_IS_ADDR_LOOPBACK(&s_in.sin_addr)) + bind_addr = c->ip4.addr_out.s_addr; + + s = sock_l4(c, AF_INET, IPPROTO_UDP, &bind_addr, + bind_if, src, uref.u32); + if (s < 0) + return p->count; + + udp_tap_map[V4][src].sock = s; + bitmap_set(udp_act[V4][UDP_ACT_TAP], src); + } + + udp_tap_map[V4][src].ts = now->tv_sec; } else { s_in6 = (struct sockaddr_in6) { .sin6_family = AF_INET6, .sin6_port = uh->dest, .sin6_addr = *(struct in6_addr *)addr, }; - const void *bind_addr = &in6addr_any; + const struct in6_addr *bind_addr = &in6addr_any; sa = (struct sockaddr *)&s_in6; sl = sizeof(s_in6); @@ -898,9 +908,19 @@ int udp_tap_handler(struct ctx *c, int af, const void *addr, if (!(s = udp_tap_map[V6][src].sock)) { union udp_epoll_ref uref = { .udp.v6 = 1, .udp.port = src }; + const char *bind_if = NULL; - s = sock_l4(c, AF_INET6, IPPROTO_UDP, bind_addr, NULL, - src, uref.u32); + if (!IN6_IS_ADDR_LOOPBACK(&s_in6.sin6_addr) && + *c->ip6.ifname_out) + bind_if = c->ip6.ifname_out; + + if (!IN6_IS_ADDR_UNSPECIFIED(&c->ip6.addr_out) && + !IN6_IS_ADDR_LOOPBACK(&s_in6.sin6_addr) && + !IN6_IS_ADDR_LINKLOCAL(&s_in6.sin6_addr)) + bind_addr = &c->ip6.addr_out; + + s = sock_l4(c, AF_INET6, IPPROTO_UDP, bind_addr, + bind_if, src, uref.u32); if (s < 0) return p->count;