From af5bc85dc1297079edc9890861aaa38de0ec30df Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Sun, 9 May 2010 18:02:38 +0200 Subject: [PATCH] loopback: configure lo device on bootup --- .gitignore | 1 + Makefile.am | 13 ++- loopback-setup.c | 276 +++++++++++++++++++++++++++++++++++++++++++++++ loopback-setup.h | 27 +++++ main.c | 5 +- test-loopback.c | 35 ++++++ 6 files changed, 355 insertions(+), 2 deletions(-) create mode 100644 loopback-setup.c create mode 100644 loopback-setup.h create mode 100644 test-loopback.c diff --git a/.gitignore b/.gitignore index d2ce04d30..b9cb51c0e 100644 --- a/.gitignore +++ b/.gitignore @@ -1,5 +1,6 @@ *~ test-ns +test-loopback systemd-initctl.service systemd-logger.service systemd-cgroups-agent diff --git a/Makefile.am b/Makefile.am index c98ad0b8b..c38c7d575 100644 --- a/Makefile.am +++ b/Makefile.am @@ -53,7 +53,8 @@ pkglibexec_PROGRAMS = \ noinst_PROGRAMS = \ test-engine \ test-job-type \ - test-ns + test-ns \ + test-loopback dbuspolicy_DATA = \ org.freedesktop.systemd1.conf @@ -155,6 +156,8 @@ COMMON_SOURCES = \ mount-setup.h \ hostname-setup.c \ hostname-setup.h \ + loopback-setup.c \ + loopback-setup.h \ utmp-wtmp.c \ utmp-wtmp.h \ specifier.c \ @@ -203,6 +206,14 @@ test_ns_SOURCES = \ test_ns_CPPFLAGS = $(systemd_CPPFLAGS) test_ns_LDADD = $(systemd_LDADD) +test_loopback_SOURCES = \ + $(BASIC_SOURCES) \ + test-loopback.c \ + loopback-setup.c + +test_loopback_CPPFLAGS = $(systemd_CPPFLAGS) +test_loopback_LDADD = $(systemd_LDADD) + systemd_logger_SOURCES = \ $(BASIC_SOURCES) \ logger.c diff --git a/loopback-setup.c b/loopback-setup.c new file mode 100644 index 000000000..e37bf4190 --- /dev/null +++ b/loopback-setup.c @@ -0,0 +1,276 @@ +/*-*- Mode: C; c-basic-offset: 8 -*-*/ + +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 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 + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with systemd; If not, see . +***/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "util.h" +#include "macro.h" +#include "loopback-setup.h" + +enum { + REQUEST_NONE = 0, + REQUEST_ADDRESS_IPV4 = 1, + REQUEST_ADDRESS_IPV6 = 2, + REQUEST_FLAGS = 4, + REQUEST_ALL = 7 +}; + +#define NLMSG_TAIL(nmsg) \ + ((struct rtattr *) (((uint8_t*) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len))) + +static int add_rtattr(struct nlmsghdr *n, size_t max_length, int type, const void *data, size_t data_length) { + size_t length; + struct rtattr *rta; + + length = RTA_LENGTH(data_length); + + if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(length) > max_length) + return -E2BIG; + + rta = NLMSG_TAIL(n); + rta->rta_type = type; + rta->rta_len = length; + memcpy(RTA_DATA(rta), data, data_length); + n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(length); + + return 0; +} + +static ssize_t sendto_loop(int fd, const void *buf, size_t buf_len, int flags, const struct sockaddr *sa, socklen_t sa_len) { + + for (;;) { + ssize_t l; + + if ((l = sendto(fd, buf, buf_len, flags, sa, sa_len)) >= 0) + return l; + + if (errno != EINTR) + return -errno; + } +} + +static ssize_t recvfrom_loop(int fd, void *buf, size_t buf_len, int flags, struct sockaddr *sa, socklen_t *sa_len) { + + for (;;) { + ssize_t l; + + if ((l = recvfrom(fd, buf, buf_len, flags, sa, sa_len)) >= 0) + return l; + + if (errno != EINTR) + return -errno; + } +} + +static int add_adresses(int fd, int if_loopback) { + union { + struct sockaddr sa; + struct sockaddr_nl nl; + } sa; + union { + struct nlmsghdr header; + uint8_t buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) + + NLMSG_ALIGN(sizeof(struct ifaddrmsg)) + + RTA_LENGTH(sizeof(struct in6_addr))]; + } request; + + struct ifaddrmsg *ifaddrmsg; + uint32_t ipv4_address = htonl(INADDR_LOOPBACK); + int r; + + zero(request); + + request.header.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)); + request.header.nlmsg_type = RTM_NEWADDR; + request.header.nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE|NLM_F_ACK; + request.header.nlmsg_seq = REQUEST_ADDRESS_IPV4; + + ifaddrmsg = NLMSG_DATA(&request.header); + ifaddrmsg->ifa_family = AF_INET; + ifaddrmsg->ifa_prefixlen = 8; + ifaddrmsg->ifa_flags = IFA_F_PERMANENT; + ifaddrmsg->ifa_scope = RT_SCOPE_HOST; + ifaddrmsg->ifa_index = if_loopback; + + if ((r = add_rtattr(&request.header, sizeof(request), IFA_LOCAL, &ipv4_address, sizeof(ipv4_address))) < 0) + return r; + + zero(sa); + sa.nl.nl_family = AF_NETLINK; + + if (sendto_loop(fd, &request, request.header.nlmsg_len, 0, &sa.sa, sizeof(sa)) < 0) + return -errno; + + request.header.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)); + request.header.nlmsg_seq = REQUEST_ADDRESS_IPV6; + + ifaddrmsg->ifa_family = AF_INET6; + ifaddrmsg->ifa_prefixlen = 128; + + if ((r = add_rtattr(&request.header, sizeof(request), IFA_LOCAL, &in6addr_loopback, sizeof(in6addr_loopback))) < 0) + return r; + + if (sendto_loop(fd, &request, request.header.nlmsg_len, 0, &sa.sa, sizeof(sa)) < 0) + return -errno; + + return 0; +} + +static int start_interface(int fd, int if_loopback) { + union { + struct sockaddr sa; + struct sockaddr_nl nl; + } sa; + union { + struct nlmsghdr header; + uint8_t buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) + + NLMSG_ALIGN(sizeof(struct ifinfomsg))]; + } request; + + struct ifinfomsg *ifinfomsg; + + zero(request); + + request.header.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)); + request.header.nlmsg_type = RTM_NEWLINK; + request.header.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK; + request.header.nlmsg_seq = REQUEST_FLAGS; + + ifinfomsg = NLMSG_DATA(&request.header); + ifinfomsg->ifi_family = AF_UNSPEC; + ifinfomsg->ifi_index = if_loopback; + ifinfomsg->ifi_flags = IFF_UP; + ifinfomsg->ifi_change = IFF_UP; + + zero(sa); + sa.nl.nl_family = AF_NETLINK; + + if (sendto_loop(fd, &request, request.header.nlmsg_len, 0, &sa.sa, sizeof(sa)) < 0) + return -errno; + + return 0; +} + +static int read_response(int fd) { + union { + struct sockaddr sa; + struct sockaddr_nl nl; + } sa; + union { + struct nlmsghdr header; + uint8_t buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) + + NLMSG_ALIGN(sizeof(struct nlmsgerr))]; + } response; + + ssize_t l; + socklen_t sa_len = sizeof(sa); + struct nlmsgerr *nlmsgerr; + + if ((l = recvfrom_loop(fd, &response, sizeof(response), 0, &sa.sa, &sa_len)) < 0) + return -errno; + + if (sa_len != sizeof(sa.nl) || + sa.nl.nl_family != AF_NETLINK) + return -EIO; + + if (sa.nl.nl_pid != 0) + return 0; + + if ((size_t) l < sizeof(struct nlmsghdr)) + return -EIO; + + if (response.header.nlmsg_type != NLMSG_ERROR || + (pid_t) response.header.nlmsg_pid != getpid() || + response.header.nlmsg_seq >= REQUEST_ALL) + return 0; + + if ((size_t) l < NLMSG_LENGTH(sizeof(struct nlmsgerr)) || + response.header.nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) + return -EIO; + + nlmsgerr = NLMSG_DATA(&response.header); + + if (nlmsgerr->error < 0 && nlmsgerr->error != -EEXIST) + return nlmsgerr->error; + + return response.header.nlmsg_seq; +} + +int loopback_setup(void) { + int r, if_loopback; + union { + struct sockaddr sa; + struct sockaddr_nl nl; + struct sockaddr_storage storage; + } sa; + int requests = REQUEST_NONE; + + int fd; + + errno = 0; + if ((if_loopback = (int) if_nametoindex("lo")) <= 0) + return errno ? -errno : -ENODEV; + + if ((fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) < 0) + return -errno; + + zero(sa); + sa.nl.nl_family = AF_NETLINK; + + if (bind(fd, &sa.sa, sizeof(sa)) < 0) { + r = -errno; + goto finish; + } + + if ((r = add_adresses(fd, if_loopback)) < 0) + goto finish; + + if ((r = start_interface(fd, if_loopback)) < 0) + goto finish; + + do { + if ((r = read_response(fd)) < 0) + goto finish; + + requests |= r; + + } while (requests != REQUEST_ALL); + + r = 0; + +finish: + if (r < 0) + log_error("Failed to configure loopback device: %s", strerror(-r)); + + if (fd >= 0) + close_nointr_nofail(fd); + + return r; +} diff --git a/loopback-setup.h b/loopback-setup.h new file mode 100644 index 000000000..b4614fa5b --- /dev/null +++ b/loopback-setup.h @@ -0,0 +1,27 @@ +/*-*- Mode: C; c-basic-offset: 8 -*-*/ + +#ifndef fooloopbacksetuphfoo +#define fooloopbacksetuphfoo + +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 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 + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with systemd; If not, see . +***/ + +int loopback_setup(void); + +#endif diff --git a/main.c b/main.c index 0128787d1..aa58040ff 100644 --- a/main.c +++ b/main.c @@ -36,6 +36,7 @@ #include "log.h" #include "mount-setup.h" #include "hostname-setup.h" +#include "loopback-setup.h" #include "load-fragment.h" #include "fdset.h" @@ -641,8 +642,10 @@ int main(int argc, char *argv[]) { log_debug("systemd running in %s mode.", manager_running_as_to_string(running_as)); - if (running_as == MANAGER_INIT) + if (running_as == MANAGER_INIT) { hostname_setup(); + loopback_setup(); + } if ((r = manager_new(running_as, confirm_spawn, &m)) < 0) { log_error("Failed to allocate manager object: %s", strerror(-r)); diff --git a/test-loopback.c b/test-loopback.c new file mode 100644 index 000000000..5cd7b41e1 --- /dev/null +++ b/test-loopback.c @@ -0,0 +1,35 @@ +/*-*- Mode: C; c-basic-offset: 8 -*-*/ + +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 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 + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with systemd; If not, see . +***/ + +#include +#include +#include + +#include "loopback-setup.h" + +int main(int argc, char* argv[]) { + int r; + + if ((r = loopback_setup()) < 0) + fprintf(stderr, "loopback: %s\n", strerror(-r)); + + return 0; +} -- 2.30.2