From 12874f5d761b4b80ac27c1fc758a93b69d92c34c Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Wed, 30 Aug 2006 19:51:54 +0000 Subject: [PATCH] add netlink support git-svn-id: file:///home/lennart/svn/public/avahi/trunk@1287 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe --- avahi-autoipd/Makefile.am | 2 +- avahi-autoipd/iface-linux.c | 297 ++++++++++++++++++++++++++++++++++++ avahi-autoipd/iface.h | 35 +++++ avahi-autoipd/main.c | 105 +++++++++---- avahi-autoipd/main.h | 46 ++++++ 5 files changed, 452 insertions(+), 33 deletions(-) create mode 100644 avahi-autoipd/iface-linux.c create mode 100644 avahi-autoipd/iface.h create mode 100644 avahi-autoipd/main.h diff --git a/avahi-autoipd/Makefile.am b/avahi-autoipd/Makefile.am index 33df1f5..adfe70d 100644 --- a/avahi-autoipd/Makefile.am +++ b/avahi-autoipd/Makefile.am @@ -28,7 +28,7 @@ AM_CFLAGS+='-DDEBUG_TRAP=__asm__("int $$3")' sbin_PROGRAMS = avahi-autoipd -avahi_autoipd_SOURCES = main.c +avahi_autoipd_SOURCES = main.c ../avahi-daemon/setproctitle.c iface.h main.h iface-linux.c avahi_autoipd_CFLAGS = $(AM_CFLAGS) $(LIBDAEMON_CFLAGS) avahi_autoipd_LDADD = $(AM_LDADD) ../avahi-common/libavahi-common.la $(LIBDAEMON_LIBS) diff --git a/avahi-autoipd/iface-linux.c b/avahi-autoipd/iface-linux.c new file mode 100644 index 0000000..c2f24df --- /dev/null +++ b/avahi-autoipd/iface-linux.c @@ -0,0 +1,297 @@ +/* $Id$ */ + +/*** + This file is part of avahi. + + avahi 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. + + avahi 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 avahi; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 + USA. +***/ + +#ifdef HAVE_CONFIG_H +#include +#endif + +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#include + +#include +#include + +#include "iface.h" + +static int fd = -1; +static int ifindex = -1; + +typedef struct Address Address; + +struct Address { + uint32_t address; + AVAHI_LLIST_FIELDS(Address, addresses); +}; + +AVAHI_LLIST_HEAD(Address, addresses) = NULL; + +int iface_init(int i) { + struct sockaddr_nl addr; + + if ((fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE)) < 0) { + daemon_log(LOG_ERR, "socket(PF_NETLINK): %s", strerror(errno)); + goto fail; + } + + memset(&addr, 0, sizeof(addr)); + addr.nl_family = AF_NETLINK; + addr.nl_groups = RTMGRP_LINK|RTMGRP_IPV4_IFADDR; + addr.nl_pid = getpid(); + + if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { + daemon_log(LOG_ERR, "bind(): %s", strerror(errno)); + goto fail; + } + + ifindex = i; + + return fd; + +fail: + if (fd >= 0) { + close(fd); + fd = -1; + } + + return -1; +} + +static int process_nlmsg(struct nlmsghdr *n) { + assert(n); + + if (n->nlmsg_type == RTM_NEWLINK || n->nlmsg_type == RTM_DELLINK) { + /* A link appeared or was removed */ + + struct ifinfomsg *ifi; + ifi = NLMSG_DATA(n); + + if (ifi->ifi_family != AF_UNSPEC || ifi->ifi_index != ifindex) + return 0; + + if (n->nlmsg_type == RTM_DELLINK) { + daemon_log(LOG_ERR, "Interface vanished."); + return -1; + } + + assert(n->nlmsg_type == RTM_NEWLINK); + + if ((ifi->ifi_flags & IFF_LOOPBACK) || + (ifi->ifi_flags & IFF_NOARP) || + !(ifi->ifi_flags & IFF_UP) || + ifi->ifi_type != ARPHRD_ETHER) { + daemon_log(LOG_ERR, "Interface not suitable."); + return -1; + } + + } else if (n->nlmsg_type == RTM_NEWADDR || n->nlmsg_type == RTM_DELADDR) { + + /* An address was added or removed */ + + struct rtattr *a = NULL; + struct ifaddrmsg *ifa; + int l; + uint32_t address = 0; + Address *i; + char buf[32]; + + ifa = NLMSG_DATA(n); + + if (ifa->ifa_family != AF_INET || ifa->ifa_index != ifindex) + return 0; + + l = NLMSG_PAYLOAD(n, sizeof(*ifa)); + a = IFLA_RTA(ifa); + + while(RTA_OK(a, l)) { + + switch(a->rta_type) { + case IFA_LOCAL: + case IFA_ADDRESS: + assert(RTA_PAYLOAD(a) == 4); + memcpy(&address, RTA_DATA(a), sizeof(uint32_t)); + break; + } + + a = RTA_NEXT(a, l); + } + + daemon_log(LOG_INFO, "%s", inet_ntop(AF_INET, &address, buf, sizeof(buf))); + + if (!address || is_ll_address(address)) + return 0; + + for (i = addresses; i; i = i->addresses_next) + if (i->address == address) + break; + + if (n->nlmsg_type == RTM_DELADDR && i) { + AVAHI_LLIST_REMOVE(Address, addresses, addresses, i); + avahi_free(i); + } if (n->nlmsg_type == RTM_NEWADDR && !i) { + i = avahi_new(Address, 1); + i->address = address; + AVAHI_LLIST_PREPEND(Address, addresses, addresses, i); + } + } + + return 0; +} + +static int process_response(int wait_for_done, unsigned seq) { + assert(fd >= 0); + + do { + size_t bytes; + ssize_t r; + char replybuf[2048]; + struct nlmsghdr *p = (struct nlmsghdr *) replybuf; + + if ((r = recv(fd, replybuf, sizeof(replybuf), 0)) < 0) { + daemon_log(LOG_ERR, "recv() failed: %s", strerror(errno)); + return -1; + } + + bytes = (size_t) r; + + for (; bytes > 0; p = NLMSG_NEXT(p, bytes)) { + + if (!NLMSG_OK(p, bytes) || bytes < sizeof(struct nlmsghdr) || bytes < p->nlmsg_len) { + daemon_log(LOG_ERR, "Netlink packet too small."); + return -1; + } + + if (p->nlmsg_type == NLMSG_DONE && wait_for_done && p->nlmsg_seq == seq) + return 0; + + if (p->nlmsg_type == NLMSG_ERROR) { + struct nlmsgerr *e = (struct nlmsgerr *) NLMSG_DATA (p); + + if (e->error) { + daemon_log(LOG_ERR, "Netlink error: %s", strerror(-e->error)); + return -1; + } + } + + if ((pid_t) p->nlmsg_pid != getpid()) + continue; + + if (process_nlmsg(p) < 0) + return -1; + } + } while (wait_for_done); + + return 0; +} + +int iface_get_initial_state(State *state) { + struct nlmsghdr *n; + struct ifinfomsg *ifi; + struct ifaddrmsg *ifa; + uint8_t req[1024]; + int seq = 0; + + assert(fd >= 0); + assert(state); + + memset(&req, 0, sizeof(req)); + n = (struct nlmsghdr*) req; + n->nlmsg_len = NLMSG_LENGTH(sizeof(*ifi)); + n->nlmsg_type = RTM_GETLINK; + n->nlmsg_seq = seq; + n->nlmsg_flags = NLM_F_MATCH|NLM_F_REQUEST|NLM_F_ACK; + n->nlmsg_pid = 0; + + ifi = NLMSG_DATA(n); + ifi->ifi_family = AF_UNSPEC; + ifi->ifi_change = -1; + + if (send(fd, n, n->nlmsg_len, 0) < 0) { + daemon_log(LOG_ERR, "send(): %s", strerror(errno)); + return -1; + } + + if (process_response(1, 0) < 0) + return -1; + + n->nlmsg_type = RTM_GETADDR; + n->nlmsg_len = NLMSG_LENGTH(sizeof(*ifa)); + n->nlmsg_seq = ++seq; + + ifa = NLMSG_DATA(n); + ifa->ifa_family = AF_INET; + ifa->ifa_index = ifindex; + + if (send(fd, n, n->nlmsg_len, 0) < 0) { + daemon_log(LOG_ERR, "send(): %s", strerror(errno)); + return -1; + } + + if (process_response(1, seq) < 0) + return -1; + + *state = addresses ? STATE_SLEEPING : STATE_START; + + return 0; +} + +int iface_process(Event *event) { + int b; + assert(fd >= 0); + + b = !!addresses; + + if (process_response(0, 0) < 0) + return -1; + + if (b && !!addresses) + *event = EVENT_ROUTABLE_ADDR_UNCONFIGURED; + else if (!b && addresses) + *event = EVENT_ROUTABLE_ADDR_CONFIGURED; + + return 0; +} + +void iface_done(void) { + Address *a; + + if (fd >= 0) { + close(fd); + fd = -1; + } + + while ((a = addresses)) { + AVAHI_LLIST_REMOVE(Address, addresses, addresses, a); + avahi_free(a); + } +} + + diff --git a/avahi-autoipd/iface.h b/avahi-autoipd/iface.h new file mode 100644 index 0000000..4480c97 --- /dev/null +++ b/avahi-autoipd/iface.h @@ -0,0 +1,35 @@ +#ifndef fooavahiifacehfoo +#define fooavahiifacehfoo + +/* $Id$ */ + +/*** + This file is part of avahi. + + avahi 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. + + avahi 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 avahi; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 + USA. +***/ + +#include + +#include "main.h" + +int iface_init(int ifindex); +int iface_process(Event *event); +void iface_done(void); + +int iface_get_initial_state(State *state); + +#endif diff --git a/avahi-autoipd/main.c b/avahi-autoipd/main.c index 8ce7da1..200cab0 100644 --- a/avahi-autoipd/main.c +++ b/avahi-autoipd/main.c @@ -43,12 +43,17 @@ #include #include +#include + #include #include #include #include #include +#include "main.h" +#include "iface.h" + #ifndef __linux__ #error "avahi-autoipd is only available on Linux for now" #endif @@ -74,17 +79,6 @@ #define ETHER_ADDRLEN 6 #define ARP_PACKET_SIZE (8+4+4+2*ETHER_ADDRLEN) -typedef enum State { - STATE_INVALID, - STATE_WAITING_PROBE, - STATE_PROBING, - STATE_WAITING_ANNOUNCE, - STATE_ANNOUNCING, - STATE_RUNNING, - STATE_SLEEPING, - STATE_MAX -} State; - typedef enum ArpOperation { ARP_REQUEST = 1, ARP_RESPONSE = 2 @@ -97,7 +91,7 @@ typedef struct ArpPacketInfo { uint8_t sender_hw_address[ETHER_ADDRLEN], target_hw_address[ETHER_ADDRLEN]; } ArpPacketInfo; -static State state = STATE_INVALID; +static State state = STATE_START; static int n_iteration = 0; static int n_conflict = 0; @@ -212,7 +206,7 @@ static int packet_parse(const void *data, size_t packet_len, ArpPacketInfo *info static void set_state(State st, int reset_counter) { const char* const state_table[] = { - [STATE_INVALID] = "INVALID", + [STATE_START] = "START", [STATE_WAITING_PROBE] = "WAITING_PROBE", [STATE_PROBING] = "PROBING", [STATE_WAITING_ANNOUNCE] = "WAITING_ANNOUNCE", @@ -347,7 +341,7 @@ fail: return -1; } -static int is_ll_address(uint32_t addr) { +int is_ll_address(uint32_t addr) { return (ntohl(addr) & IPV4LL_NETMASK) == IPV4LL_NETWORK; } @@ -366,6 +360,12 @@ static struct timeval *elapse_time(struct timeval *tv, unsigned msec, unsigned j } static int loop(int iface, uint32_t addr) { + enum { + FD_ARP, + FD_IFACE, + FD_MAX + }; + int fd = -1, ret = -1; struct timeval next_wakeup; int next_wakeup_valid = 0; @@ -375,17 +375,19 @@ static int loop(int iface, uint32_t addr) { void *out_packet = NULL; size_t out_packet_len; uint8_t hw_address[ETHER_ADDRLEN]; - struct pollfd pollfds[1]; + struct pollfd pollfds[FD_MAX]; + int iface_fd; + Event event = EVENT_NULL; - enum { - EVENT_NULL, - EVENT_PACKET, - EVENT_TIMEOUT - } event = EVENT_NULL; - if ((fd = open_socket(iface, hw_address)) < 0) goto fail; + if ((iface_fd = iface_init(iface)) < 0) + goto fail; + + if (iface_get_initial_state(&state) < 0) + goto fail; + if (addr && !is_ll_address(addr)) { daemon_log(LOG_WARNING, "Requested address %s is not from IPv4LL range 169.254/16, ignoring.", inet_ntop(AF_INET, &addr, buf, sizeof(buf))); addr = 0; @@ -403,15 +405,20 @@ static int loop(int iface, uint32_t addr) { daemon_log(LOG_INFO, "Starting with address %s", inet_ntop(AF_INET, &addr, buf, sizeof(buf))); + if (state == STATE_SLEEPING) + daemon_log(LOG_INFO, "Routable address already assigned, sleeping."); + memset(pollfds, 0, sizeof(pollfds)); - pollfds[0].fd = fd; - pollfds[0].events = POLLIN; + pollfds[FD_ARP].fd = fd; + pollfds[FD_ARP].events = POLLIN; + pollfds[FD_IFACE].fd = iface_fd; + pollfds[FD_IFACE].events = POLLIN; for (;;) { int r, timeout; AvahiUsec usec; - if (state == STATE_INVALID) { + if (state == STATE_START) { /* First, wait a random time */ set_state(STATE_WAITING_PROBE, 1); @@ -488,10 +495,10 @@ static int loop(int iface, uint32_t addr) { daemon_log(LOG_INFO, "Trying address %s", inet_ntop(AF_INET, &addr, buf, sizeof(buf))); - set_state(STATE_WAITING_PROBE, 1); - n_conflict++; + set_state(STATE_WAITING_PROBE, 1); + if (n_conflict >= MAX_CONFLICTS) { daemon_log(LOG_WARNING, "Got too many conflicts, rate limiting new probes."); elapse_time(&next_wakeup, RATE_LIMIT_INTERVAL*1000, PROBE_WAIT*1000); @@ -502,6 +509,25 @@ static int loop(int iface, uint32_t addr) { } else daemon_log(LOG_DEBUG, "Ignoring ARP packet."); } + + } else if (event == EVENT_ROUTABLE_ADDR_CONFIGURED) { + + daemon_log(LOG_INFO, "A routable address has been configured."); + + set_state(STATE_SLEEPING, 1); + + if (state == STATE_RUNNING || state == STATE_ANNOUNCING) + remove_address(iface, addr); + + } else if (event == EVENT_ROUTABLE_ADDR_UNCONFIGURED && state == STATE_SLEEPING) { + + daemon_log(LOG_INFO, "No longer a routable address configured, restarting probe process."); + + set_state(STATE_WAITING_PROBE, 1); + + elapse_time(&next_wakeup, 0, PROBE_WAIT*1000); + next_wakeup_valid = 1; + } if (out_packet) { @@ -519,6 +545,7 @@ static int loop(int iface, uint32_t addr) { in_packet = NULL; } + event = EVENT_NULL; timeout = -1; if (next_wakeup_valid) { @@ -528,7 +555,7 @@ static int loop(int iface, uint32_t addr) { daemon_log(LOG_DEBUG, "sleeping %ims", timeout); - while ((r = poll(pollfds, 1, timeout)) < 0 && errno == EINTR) + while ((r = poll(pollfds, FD_MAX, timeout)) < 0 && errno == EINTR) ; if (r < 0) { @@ -538,13 +565,21 @@ static int loop(int iface, uint32_t addr) { event = EVENT_TIMEOUT; next_wakeup_valid = 0; } else { - assert(pollfds[0].revents == POLLIN); - if (recv_packet(fd, &in_packet, &in_packet_len) < 0) - goto fail; + if (pollfds[FD_ARP].revents == POLLIN) { + if (recv_packet(fd, &in_packet, &in_packet_len) < 0) + goto fail; + + if (in_packet) + event = EVENT_PACKET; + } - if (in_packet) - event = EVENT_PACKET; + if (event == EVENT_NULL && + pollfds[FD_IFACE].revents == POLLIN) { + + if (iface_process(&event) < 0) + goto fail; + } } } @@ -557,6 +592,9 @@ fail: if (fd >= 0) close(fd); + + if (iface_fd >= 0) + iface_done(); return ret; } @@ -594,6 +632,8 @@ int main(int argc, char*argv[]) { int ifindex; uint32_t addr = 0; + avahi_init_proc_title(argc, argv); + init_rand_seed(); if ((ifindex = get_ifindex(argc >= 2 ? argv[1] : "eth0")) < 0) @@ -624,5 +664,6 @@ fail: - signals - store last used address - cmdline +- setproctitle */ diff --git a/avahi-autoipd/main.h b/avahi-autoipd/main.h new file mode 100644 index 0000000..61d5ed6 --- /dev/null +++ b/avahi-autoipd/main.h @@ -0,0 +1,46 @@ +#ifndef fooavahimainhfoo +#define fooavahimainhfoo + +/* $Id$ */ + +/*** + This file is part of avahi. + + avahi 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. + + avahi 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 avahi; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 + USA. +***/ + +typedef enum Event { + EVENT_NULL, + EVENT_PACKET, + EVENT_TIMEOUT, + EVENT_ROUTABLE_ADDR_CONFIGURED, + EVENT_ROUTABLE_ADDR_UNCONFIGURED, +} Event; + +typedef enum State { + STATE_START, + STATE_WAITING_PROBE, + STATE_PROBING, + STATE_WAITING_ANNOUNCE, + STATE_ANNOUNCING, + STATE_RUNNING, + STATE_SLEEPING, + STATE_MAX +} State; + +int is_ll_address(uint32_t addr); + +#endif -- 2.39.5