From c75acc64833eb7263b340079e7ba3153ebc60aec Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Thu, 30 May 2013 16:25:26 +1000 Subject: [PATCH 1/1] discover: Add network handling Signed-off-by: Jeremy Kerr --- configure.ac.in | 2 + discover/Makefile.am | 2 + discover/network.c | 426 +++++++++++++++++++++++++++++++++++++++++ discover/network.h | 11 ++ discover/pb-discover.c | 6 + lib/system/system.c | 2 + lib/system/system.h | 2 + 7 files changed, 451 insertions(+) create mode 100644 discover/network.c create mode 100644 discover/network.h diff --git a/configure.ac.in b/configure.ac.in index bfc2572..1d6703b 100644 --- a/configure.ac.in +++ b/configure.ac.in @@ -195,6 +195,8 @@ DEFINE_HOST_PROG(SFTP, sftp, [/usr/bin/sftp]) DEFINE_HOST_PROG(TFTP, tftp, [/usr/bin/tftp]) DEFINE_HOST_PROG(UMOUNT, umount, [/bin/umount]) DEFINE_HOST_PROG(WGET, wget, [/usr/bin/wget]) +DEFINE_HOST_PROG(IP, ip, [/sbin/ip]) +DEFINE_HOST_PROG(UDHCPC, udhcpc, [/sbin/udhcpc]) default_cflags="--std=gnu99 -g \ -Wall -W -Wunused -Wstrict-prototypes -Wmissing-prototypes \ diff --git a/discover/Makefile.am b/discover/Makefile.am index ddf37ef..a449818 100644 --- a/discover/Makefile.am +++ b/discover/Makefile.am @@ -58,6 +58,8 @@ pb_discover_SOURCES = \ parser-utils.h \ pb-discover.c \ pb-discover.h \ + network.c \ + network.h \ udev.c \ udev.h \ user-event.c \ diff --git a/discover/network.c b/discover/network.c new file mode 100644 index 0000000..4a4f932 --- /dev/null +++ b/discover/network.c @@ -0,0 +1,426 @@ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#include "network.h" + +#define HWADDR_SIZE 6 +#define PIDFILE_BASE (LOCAL_STATE_DIR "/petitboot/") + +#define for_each_nlmsg(buf, nlmsg, len) \ + for (nlmsg = (struct nlmsghdr *)buf; \ + NLMSG_OK(nlmsg, len) && nlmsg->nlmsg_type != NLMSG_DONE; \ + nlmsg = NLMSG_NEXT(nlmsg, len)) + +#define for_each_rta(buf, rta, attrlen) \ + for (rta = (struct rtattr *)(buf); RTA_OK(rta, attrlen); \ + rta = RTA_NEXT(rta, attrlen)) + + +struct interface { + int ifindex; + char name[IFNAMSIZ]; + uint8_t hwaddr[HWADDR_SIZE]; + + enum { + IFSTATE_NEW, + IFSTATE_UP_WAITING_LINK, + IFSTATE_CONFIGURED, + IFSTATE_IGNORED, + } state; + + struct list_item list; +}; + +struct network { + struct list interfaces; + struct waiter *waiter; + int netlink_sd; + bool manual_config; + bool dry_run; +}; + +static const struct network_config *find_config_by_hwaddr( + uint8_t *hwaddr) +{ + const struct config *config; + int i; + + config = config_get(); + if (!config) + return NULL; + + for (i = 0; i < config->n_network_configs; i++) { + struct network_config *netconf = config->network_configs[i]; + + if (!memcmp(netconf->hwaddr, hwaddr, HWADDR_SIZE)) + return netconf; + } + + return NULL; +} + +static struct interface *find_interface_by_ifindex(struct network *network, + int ifindex) +{ + struct interface *interface; + + list_for_each_entry(&network->interfaces, interface, list) + if (interface->ifindex == ifindex) + return interface; + + return NULL; +} + +static int network_init_netlink(struct network *network) +{ + struct sockaddr_nl addr; + int rc; + + memset(&addr, 0, sizeof(addr)); + addr.nl_family = AF_NETLINK; + addr.nl_groups = RTMGRP_LINK; + + network->netlink_sd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE); + if (network->netlink_sd < 0) { + perror("socket(AF_NETLINK)"); + return -1; + } + + rc = bind(network->netlink_sd, (struct sockaddr *)&addr, sizeof(addr)); + if (rc) { + perror("bind(sockaddr_nl)"); + close(network->netlink_sd); + return -1; + } + + return 0; +} + +static int network_send_link_query(struct network *network) +{ + int rc; + struct { + struct nlmsghdr nlmsg; + struct rtgenmsg rtmsg; + } msg; + + memset(&msg, 0, sizeof(msg)); + + msg.nlmsg.nlmsg_len = sizeof(msg); + msg.nlmsg.nlmsg_type = RTM_GETLINK; + msg.nlmsg.nlmsg_flags = NLM_F_REQUEST | NLM_F_ROOT; + msg.nlmsg.nlmsg_seq = 0; + msg.nlmsg.nlmsg_pid = 0; + msg.rtmsg.rtgen_family = AF_UNSPEC; + + rc = send(network->netlink_sd, &msg, sizeof(msg), MSG_NOSIGNAL); + if (rc != sizeof(msg)) + return -1; + + return 0; +} + +static int interface_up(struct network *network, struct interface *interface) +{ + int rc; + const char *argv[] = { + pb_system_apps.ip, + "link", + "set", + interface->name, + "up", + NULL, + }; + + rc = pb_run_cmd(argv, 1, network->dry_run); + if (rc) { + pb_log("failed to bring interface %s up\n", interface->name); + return -1; + } + return 0; +} + +static void configure_interface_dhcp(struct network *network, + struct interface *interface) +{ + char pidfile[256]; + const char *argv[] = { + pb_system_apps.udhcpc, + "-R", + "-n", + "-p", pidfile, + "-i", interface->name, + NULL, + }; + snprintf(pidfile, sizeof(pidfile), "%s/udhcpc-%s.pid", + PIDFILE_BASE, interface->name); + + pb_run_cmd(argv, 0, network->dry_run); + return; +} + +static void configure_interface_static(struct network *network, + struct interface *interface, + const struct network_config *config) +{ + const char *addr_argv[] = { + pb_system_apps.ip, + "address", + "add", + config->static_config.address, + "dev", + interface->name, + NULL, + }; + const char *route_argv[] = { + pb_system_apps.ip, + "route", + "add", + "default", + "via", + config->static_config.gateway, + NULL, + }; + int rc; + + + rc = pb_run_cmd(addr_argv, 1, network->dry_run); + if (rc) { + pb_log("failed to add address %s to interface %s\n", + config->static_config.address, + interface->name); + return; + } + + /* we need the interface up before we can route through it */ + rc = interface_up(network, interface); + if (rc) + return; + + if (config->static_config.gateway) + rc = pb_run_cmd(route_argv, 1, network->dry_run); + + if (rc) { + pb_log("failed to add default route %s on interface %s\n", + config->static_config.gateway, + interface->name); + } + + return; +} + +static void configure_interface(struct network *network, + struct interface *interface, bool up, bool link) +{ + const struct network_config *config = NULL; + + if (interface->state == IFSTATE_IGNORED) + return; + + /* old interface? check that we're still up and running */ + if (interface->state == IFSTATE_CONFIGURED) { + if (!up) + interface->state = IFSTATE_NEW; + else if (!link) + interface->state = IFSTATE_UP_WAITING_LINK; + else + return; + } + + /* always up the lookback, no other handling required */ + if (!strcmp(interface->name, "lo")) { + if (interface->state == IFSTATE_NEW) + interface_up(network, interface); + interface->state = IFSTATE_CONFIGURED; + return; + } + + config = find_config_by_hwaddr(interface->hwaddr); + if (config && config->ignore) { + pb_log("network: ignoring interface %s\n", interface->name); + interface->state = IFSTATE_IGNORED; + return; + } + + /* if we're in manual config mode, we need an interface configuration */ + if (network->manual_config && !config) { + interface->state = IFSTATE_IGNORED; + pb_log("network: skipping %s: manual config mode, " + "but no config for this interface\n", + interface->name); + return; + } + + /* new interface? bring up to the point so we can detect a link */ + if (interface->state == IFSTATE_NEW) { + if (!up) { + interface_up(network, interface); + pb_log("network: bringing up interface %s\n", + interface->name); + return; + + } else if (!link) { + interface->state = IFSTATE_UP_WAITING_LINK; + } + } + + /* no link? wait for a notification */ + if (interface->state == IFSTATE_UP_WAITING_LINK && !link) + return; + + pb_log("network: configuring interface %s\n", interface->name); + + if (!config || config->method == CONFIG_METHOD_DHCP) { + configure_interface_dhcp(network, interface); + + } else if (config->method == CONFIG_METHOD_STATIC) { + configure_interface_static(network, interface, config); + } +} + +static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg) +{ + bool have_ifaddr, have_ifname; + struct interface *interface; + struct ifinfomsg *info; + struct rtattr *attr; + uint8_t ifaddr[6]; + char ifname[IFNAMSIZ+1]; + int attrlen, type; + + + /* we're only interested in NEWLINK messages */ + type = nlmsg->nlmsg_type; + if (!(type == RTM_NEWLINK || type == RTM_DELLINK)) + return 0; + + info = NLMSG_DATA(nlmsg); + + have_ifaddr = have_ifname = false; + + attrlen = nlmsg->nlmsg_len - sizeof(*info); + + /* extract the interface name and hardware address attributes */ + for_each_rta(info + 1, attr, attrlen) { + void *data = RTA_DATA(attr); + + switch (attr->rta_type) { + case IFLA_ADDRESS: + memcpy(ifaddr, data, sizeof(ifaddr)); + have_ifaddr = true; + break; + + case IFLA_IFNAME: + strncpy(ifname, data, IFNAMSIZ); + have_ifname = true; + break; + } + } + + if (!have_ifaddr || !have_ifname) + return -1; + + if (type == RTM_DELLINK) { + interface = find_interface_by_ifindex(network, info->ifi_index); + if (!interface) + return 0; + pb_log("network: interface %s removed\n", interface->name); + list_remove(&interface->list); + talloc_free(interface); + return 0; + } + + + interface = find_interface_by_ifindex(network, info->ifi_index); + if (!interface) { + interface = talloc_zero(network, struct interface); + interface->ifindex = info->ifi_index; + interface->state = IFSTATE_NEW; + memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr)); + strncpy(interface->name, ifname, sizeof(interface->name) - 1); + } + + configure_interface(network, interface, + info->ifi_flags & IFF_UP, + info->ifi_flags & IFF_LOWER_UP); + + return 0; +} + +static int network_netlink_process(void *arg) +{ + struct network *network = arg; + struct nlmsghdr *nlmsg; + unsigned int len; + char buf[4096]; + int rc; + + rc = recv(network->netlink_sd, buf, sizeof(buf), 0); + if (rc < 0) { + perror("netlink recv"); + return -1; + } + + len = rc; + + for_each_nlmsg(buf, nlmsg, len) + network_handle_nlmsg(network, nlmsg); + + return 0; +} + +struct network *network_init(void *ctx, struct waitset *waitset, bool dry_run) +{ + struct network *network; + int rc; + + network = talloc(ctx, struct network); + list_init(&network->interfaces); + network->manual_config = false; + network->dry_run = dry_run; + + rc = network_init_netlink(network); + if (rc) + goto err; + + network->waiter = waiter_register_io(waitset, network->netlink_sd, + WAIT_IN, network_netlink_process, network); + + if (!network->waiter) + goto err; + + rc = network_send_link_query(network); + if (rc) + goto err; + + return network; + +err: + network_shutdown(network); + return NULL; +} + + +int network_shutdown(struct network *network) +{ + if (network->waiter) + waiter_remove(network->waiter); + + close(network->netlink_sd); + talloc_free(network); + return 0; +} diff --git a/discover/network.h b/discover/network.h new file mode 100644 index 0000000..c90af40 --- /dev/null +++ b/discover/network.h @@ -0,0 +1,11 @@ +#ifndef NETWORK_H +#define NETWORK_H + +struct network; +struct waitset; + +struct network *network_init(void *ctx, struct waitset *waitset, bool dry_run); +int network_shutdown(struct network *network); + +#endif /* NETWORK_H */ + diff --git a/discover/pb-discover.c b/discover/pb-discover.c index fac1c9d..986401d 100644 --- a/discover/pb-discover.c +++ b/discover/pb-discover.c @@ -17,6 +17,7 @@ #include "user-event.h" #include "discover-server.h" #include "device-handler.h" +#include "network.h" static void print_version(void) { @@ -108,6 +109,7 @@ int main(int argc, char *argv[]) { struct device_handler *handler; struct discover_server *server; + struct network *network; struct waitset *waitset; struct opts opts; struct pb_udev *udev; @@ -154,6 +156,10 @@ int main(int argc, char *argv[]) if (!server) return EXIT_FAILURE; + network = network_init(server, waitset, opts.dry_run == opt_yes); + if (!network) + return EXIT_FAILURE; + handler = device_handler_init(server, waitset, opts.dry_run == opt_yes); if (!handler) return EXIT_FAILURE; diff --git a/lib/system/system.c b/lib/system/system.c index 13dc146..dbdef46 100644 --- a/lib/system/system.c +++ b/lib/system/system.c @@ -26,6 +26,8 @@ const struct pb_system_apps pb_system_apps = { .tftp = HOST_PROG_TFTP, .umount = HOST_PROG_UMOUNT, .wget = HOST_PROG_WGET, + .ip = HOST_PROG_IP, + .udhcpc = HOST_PROG_UDHCPC, }; int pb_mkdir_recursive(const char *dir) diff --git a/lib/system/system.h b/lib/system/system.h index f8f18a3..271c435 100644 --- a/lib/system/system.h +++ b/lib/system/system.h @@ -11,6 +11,8 @@ struct pb_system_apps { const char *tftp; const char *umount; const char *wget; + const char *ip; + const char *udhcpc; }; extern const struct pb_system_apps pb_system_apps; -- 2.39.2