diff options
author | Lennart Poettering <lennart@poettering.net> | 2015-09-07 16:52:24 +0200 |
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committer | Lennart Poettering <lennart@poettering.net> | 2015-09-07 18:44:30 +0200 |
commit | 7a8f63251df2202e59a76e537a688fe7500cb1ad (patch) | |
tree | 03d8862040b6db029825b25603762244fa98d089 /src/nspawn/nspawn-expose-ports.c | |
parent | e83bebeff7d9d734e17c3e38ac13daabc09518e1 (diff) |
nspawn: split all port exposure code into nspawn-expose-port.[ch]
Diffstat (limited to 'src/nspawn/nspawn-expose-ports.c')
-rw-r--r-- | src/nspawn/nspawn-expose-ports.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/src/nspawn/nspawn-expose-ports.c b/src/nspawn/nspawn-expose-ports.c new file mode 100644 index 0000000000..a6b8175e84 --- /dev/null +++ b/src/nspawn/nspawn-expose-ports.c @@ -0,0 +1,278 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2015 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "sd-netlink.h" + +#include "util.h" +#include "in-addr-util.h" +#include "firewall-util.h" +#include "local-addresses.h" +#include "netlink-util.h" + +#include "nspawn.h" +#include "nspawn-expose-ports.h" + +int expose_port_parse(ExposePort **l, const char *s) { + + const char *split, *e; + uint16_t container_port, host_port; + int protocol; + ExposePort *p; + int r; + + assert(l); + assert(s); + + if ((e = startswith(s, "tcp:"))) + protocol = IPPROTO_TCP; + else if ((e = startswith(s, "udp:"))) + protocol = IPPROTO_UDP; + else { + e = s; + protocol = IPPROTO_TCP; + } + + split = strchr(e, ':'); + if (split) { + char v[split - e + 1]; + + memcpy(v, e, split - e); + v[split - e] = 0; + + r = safe_atou16(v, &host_port); + if (r < 0 || host_port <= 0) + return -EINVAL; + + r = safe_atou16(split + 1, &container_port); + } else { + r = safe_atou16(e, &container_port); + host_port = container_port; + } + + if (r < 0 || container_port <= 0) + return -EINVAL; + + LIST_FOREACH(ports, p, *l) + if (p->protocol == protocol && p->host_port == host_port) + return -EEXIST; + + p = new(ExposePort, 1); + if (!p) + return -ENOMEM; + + p->protocol = protocol; + p->host_port = host_port; + p->container_port = container_port; + + LIST_PREPEND(ports, *l, p); + + return 0; +} + +void expose_port_free_all(ExposePort *p) { + + while (p) { + ExposePort *q = p; + LIST_REMOVE(ports, p, q); + free(q); + } +} + +int expose_port_flush(ExposePort* l, union in_addr_union *exposed) { + ExposePort *p; + int r, af = AF_INET; + + assert(exposed); + + if (!l) + return 0; + + if (in_addr_is_null(af, exposed)) + return 0; + + log_debug("Lost IP address."); + + LIST_FOREACH(ports, p, l) { + r = fw_add_local_dnat(false, + af, + p->protocol, + NULL, + NULL, 0, + NULL, 0, + p->host_port, + exposed, + p->container_port, + NULL); + if (r < 0) + log_warning_errno(r, "Failed to modify firewall: %m"); + } + + *exposed = IN_ADDR_NULL; + return 0; +} + +int expose_port_execute(sd_netlink *rtnl, ExposePort *l, union in_addr_union *exposed) { + _cleanup_free_ struct local_address *addresses = NULL; + _cleanup_free_ char *pretty = NULL; + union in_addr_union new_exposed; + ExposePort *p; + bool add; + int af = AF_INET, r; + + assert(exposed); + + /* Invoked each time an address is added or removed inside the + * container */ + + if (!l) + return 0; + + r = local_addresses(rtnl, 0, af, &addresses); + if (r < 0) + return log_error_errno(r, "Failed to enumerate local addresses: %m"); + + add = r > 0 && + addresses[0].family == af && + addresses[0].scope < RT_SCOPE_LINK; + + if (!add) + return expose_port_flush(l, exposed); + + new_exposed = addresses[0].address; + if (in_addr_equal(af, exposed, &new_exposed)) + return 0; + + in_addr_to_string(af, &new_exposed, &pretty); + log_debug("New container IP is %s.", strna(pretty)); + + LIST_FOREACH(ports, p, l) { + + r = fw_add_local_dnat(true, + af, + p->protocol, + NULL, + NULL, 0, + NULL, 0, + p->host_port, + &new_exposed, + p->container_port, + in_addr_is_null(af, exposed) ? NULL : exposed); + if (r < 0) + log_warning_errno(r, "Failed to modify firewall: %m"); + } + + *exposed = new_exposed; + return 0; +} + +int expose_port_send_rtnl(int send_fd) { + union { + struct cmsghdr cmsghdr; + uint8_t buf[CMSG_SPACE(sizeof(int))]; + } control = {}; + struct msghdr mh = { + .msg_control = &control, + .msg_controllen = sizeof(control), + }; + struct cmsghdr *cmsg; + _cleanup_close_ int fd = -1; + ssize_t k; + + assert(send_fd >= 0); + + fd = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_ROUTE); + if (fd < 0) + return log_error_errno(errno, "Failed to allocate container netlink: %m"); + + cmsg = CMSG_FIRSTHDR(&mh); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + cmsg->cmsg_len = CMSG_LEN(sizeof(int)); + memcpy(CMSG_DATA(cmsg), &fd, sizeof(int)); + + mh.msg_controllen = cmsg->cmsg_len; + + /* Store away the fd in the socket, so that it stays open as + * long as we run the child */ + k = sendmsg(send_fd, &mh, MSG_NOSIGNAL); + if (k < 0) + return log_error_errno(errno, "Failed to send netlink fd: %m"); + + return 0; +} + +int expose_port_watch_rtnl( + sd_event *event, + int recv_fd, + sd_netlink_message_handler_t handler, + union in_addr_union *exposed, + sd_netlink **ret) { + + union { + struct cmsghdr cmsghdr; + uint8_t buf[CMSG_SPACE(sizeof(int))]; + } control = {}; + struct msghdr mh = { + .msg_control = &control, + .msg_controllen = sizeof(control), + }; + struct cmsghdr *cmsg; + _cleanup_netlink_unref_ sd_netlink *rtnl = NULL; + int fd, r; + ssize_t k; + + assert(event); + assert(recv_fd >= 0); + assert(ret); + + k = recvmsg(recv_fd, &mh, MSG_NOSIGNAL); + if (k < 0) + return log_error_errno(errno, "Failed to recv netlink fd: %m"); + + cmsg = CMSG_FIRSTHDR(&mh); + assert(cmsg->cmsg_level == SOL_SOCKET); + assert(cmsg->cmsg_type == SCM_RIGHTS); + assert(cmsg->cmsg_len == CMSG_LEN(sizeof(int))); + memcpy(&fd, CMSG_DATA(cmsg), sizeof(int)); + + r = sd_netlink_open_fd(&rtnl, fd); + if (r < 0) { + safe_close(fd); + return log_error_errno(r, "Failed to create rtnl object: %m"); + } + + r = sd_netlink_add_match(rtnl, RTM_NEWADDR, handler, exposed); + if (r < 0) + return log_error_errno(r, "Failed to subscribe to RTM_NEWADDR messages: %m"); + + r = sd_netlink_add_match(rtnl, RTM_DELADDR, handler, exposed); + if (r < 0) + return log_error_errno(r, "Failed to subscribe to RTM_DELADDR messages: %m"); + + r = sd_netlink_attach_event(rtnl, event, 0); + if (r < 0) + return log_error_errno(r, "Failed to add to even loop: %m"); + + *ret = rtnl; + rtnl = NULL; + + return 0; +} |