Knowing that Hurd uses NetBSD drivers and knowing I'm very intimate with the NetBSD network stack, how true is it that IFF_RUNNING reflects carrier state?
On BSD, carrier state is part of if_data - if_link_state. Every driver in every BSD supports this even if LINK_STATE_UNKNOWN. Some drivers (but not all) also report link state via MEDIA. MacOS deviates from BSD here and does not have if_link_state and soely relies on MEDIA. On every BSD IFF_RUNNING means that kernel resources have been allocated (ie tx/rx rings setup etc etc). On Linux IFF_RUNNING means yes we have a carrier. Roy From: Martin-Éric Racine <[email protected]> To: "Roy Marples"<[email protected]> Date: Sun, 03 May 2026 09:31:19 +0100 Subject: Fwd: [PATCH 4/6] New GNU/Hurd backend ---------- Forwarded message --------- Lähettäjä: Joan Lledó < mailto:[email protected] > Date: ma 6.4.2026 klo 16.00 Subject: [PATCH 4/6] New GNU/Hurd backend To: < mailto:[email protected] > Cc: < mailto:[email protected] >, Joan Lledó < mailto:[email protected] > From: Joan Lledó < mailto:[email protected] > This adds a new main module to port dhcpdp to the Hurd. * The Hurd module relies on libpcap to work with BPF filters. * Addresses and routes are configured via ioctls to the stack. * Only IPv4 over Ethernet is supported so far. * Privilege separation and detection of network configuration changes is not implemented yet. * libpcap and liblwip are required dependencies. * Only 32-bit Hurd has been tested so far. --- src/if-hurd.c | 448 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 448 insertions(+) create mode 100644 src/if-hurd.c diff --git a/src/if-hurd.c b/src/if-hurd.c new file mode 100644 index 00000000..00482af8 --- /dev/null +++ b/src/if-hurd.c @@ -0,0 +1,448 @@ +/* SPDX-License-Identifier: BSD-2-Clause */ +/* + * libpcap interface driver for dhcpcd + * Copyright (c) 2025 Joan Lledó < mailto:[email protected] > + * All rights reserved + + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <string.h> +#include <sys/ioctl.h> +#include <net/if_arp.h> +#include <hurd.h> +#include <hurd/paths.h> +#include <hurd/pfinet.h> +#include <device/device.h> + +#include "logerr.h" +#include "if.h" +#include "dhcpcd.h" + +#define ETH_HWADDR_LEN 6 + +/* Get the MAC address from an array of int */ +#define GET_HWADDR_BYTE(x,n) (((unsigned char*)x)[n]) + +/* + * We should just use `struct ifrtreq` from net/route.h instead of defining this. + * Regrettably, dhcpcd defines some macros inside `struct rt` that conflict with + * `struct ifrtreq` fields, so we need to mimic `struct ifrtreq` here, but + * renaming the fields. + */ +struct kroute { + char ifname[IF_NAMESIZE]; + in_addr_t dest; + in_addr_t mask; + in_addr_t gateway; + int flags; + int mtu; + int metric; + char padding[sizeof(int) * 4]; +}; + +int +if_getssid(__unused struct interface *ifp) { + /* Not supported. Returning -1 means interface is not wireless */ + errno = EOPNOTSUPP; + return -1; +} + +bool +if_roaming(__unused struct interface *ifp) { + /* Not supported */ + errno = EOPNOTSUPP; + return false; +} + +static int +if_copyrt(struct dhcpcd_ctx *ctx, struct rt *dest, struct kroute *src) { + struct interface *ifp; + + ifp = if_find(ctx->ifaces, src->ifname); + if (ifp == NULL) { + logerr("%s: interface not found: %s", __func__, src->ifname); + return -1; + } + + memset(dest, 0, sizeof(struct rt)); + + dest->rt_ifp = ifp; + dest->rt_ss_dest.sin.sin_family = AF_INET; + dest->rt_ss_dest.sin.sin_len = sizeof(struct sockaddr_in); + dest->rt_ss_dest.sin.sin_addr.s_addr = src->dest; + dest->rt_ss_netmask.sin.sin_family = AF_INET; + dest->rt_ss_netmask.sin.sin_len = sizeof(struct sockaddr_in); + dest->rt_ss_netmask.sin.sin_addr.s_addr = src->mask; + dest->rt_ss_gateway.sin.sin_family = AF_INET; + dest->rt_ss_gateway.sin.sin_len = sizeof(struct sockaddr_in); + dest->rt_ss_gateway.sin.sin_addr.s_addr = src->gateway; + dest->rt_flags = (unsigned int)src->flags; + dest->rt_mtu = (unsigned int)src->mtu; +#ifdef HAVE_ROUTE_METRIC + dest->rt_metric = (unsigned int)src->metric; +#endif + + return 0; +} + +static int +if_copykrt(struct kroute *dst, const struct rt *src) { + memset(dst, 0, sizeof(struct kroute)); + + strncpy(dst->ifname, src->rt_ifp->name, IF_NAMESIZE); + dst->dest = src->rt_ss_dest.sin.sin_addr.s_addr;; + dst->mask = src->rt_ss_netmask.sin.sin_addr.s_addr; + dst->gateway = src->rt_ss_gateway.sin.sin_addr.s_addr; + dst->flags = (int)src->rt_flags; + dst->mtu = (int)src->rt_mtu; +#ifdef HAVE_ROUTE_METRIC + dst->metric = (int)src->rt_metric; +#endif + + /* Set flags. Required by pfinet, ignored by lwip */ + + /* All dhcp routes must be marked as static */ + dst->flags |= RTF_STATIC; + + /* Flag route type */ + if (dst->mask == INADDR_NONE) + /* All ones netmask means host route */ + dst->flags |= RTF_HOST; + else if (dst->mask != INADDR_ANY) + /* Subnet route */ + dst->flags &= ~RTF_HOST; + else if (dst->gateway != INADDR_ANY) + /* Netmask is any, and we got a gateway so default route */ + dst->flags |= RTF_GATEWAY; + + return 0; +} + +/* Get all routes for existing interfaces and add them to th RB tree */ +int +if_initrt(struct dhcpcd_ctx *ctx, rb_tree_t *routes, int af) { + mach_port_t pfinet; + char socket_inet[32]; + char *raw_data; + struct kroute *kroutes; + unsigned int i, len = 0, kroutes_count; + struct rt rt, *rtn = NULL; + error_t err; + + snprintf(socket_inet, sizeof(socket_inet), _SERVERS_SOCKET "/%d", af); + pfinet = file_name_lookup (socket_inet, O_RDONLY, 0); + if (pfinet == MACH_PORT_NULL) { + logerr("%s: cannot open file: %s", __func__, socket_inet); + return -1; + } + + err = pfinet_getroutes (pfinet, (vm_size_t)-1, &raw_data, &len); + if (err) { + errno = err; + logerr("%s: cannot get routes from stack", __func__); + goto errout; + } + + kroutes = (struct kroute *)raw_data; + kroutes_count = len / sizeof(struct kroute); + + for (i = 0; i < kroutes_count; i++) { + if (if_copyrt(ctx, &rt, &kroutes[i]) != 0) + goto errout; + + if ((rtn = rt_new(rt.rt_ifp)) == NULL) { + goto errout; + } + + memcpy(rtn, &rt, sizeof(*rtn)); + + if (rb_tree_insert_node(routes, rtn) != rtn) + rt_free(rtn); + } + + mach_port_deallocate (mach_task_self (), pfinet); + vm_deallocate (mach_task_self(), (vm_address_t)raw_data, len); + + return 0; + +errout: + mach_port_deallocate (mach_task_self (), pfinet); + + if (raw_data) + vm_deallocate (mach_task_self(), (vm_address_t)raw_data, len); + + return -1; +} + +int +if_vimaster(__unused struct dhcpcd_ctx *ctx, __unused const char *ifname) { + /* Used mostly for wlan. Not supported */ + errno = EOPNOTSUPP; + return -1; +} + +#ifdef INET +int +if_route(unsigned char cmd, const struct rt *rt) { + struct dhcpcd_ctx *ctx; + struct kroute krt; + + if (cmd == RTM_CHANGE) { + /* + * Asked to change route, the hurd doesn't provide a way to do this, + * available ioctls only allow adding and deleting. + * ESRCH is the expected error in this scenario. + */ + errno = ESRCH; + return -1; + } + + ctx = rt->rt_ifp->ctx; + + if_copykrt(&krt, rt); + return if_ioctl(ctx, cmd == RTM_DELETE ? SIOCDELRT : SIOCADDRT, &krt, sizeof(krt)); +} + +static int +if_ioctl_addr(struct dhcpcd_ctx *ctx, const char *ifname, + const struct in_addr *addr, ioctl_request_t cmd) { + struct ifreq ifr; + struct sockaddr_in *sin; + + memset(&ifr, 0, sizeof(ifr)); + strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)); + sin = (struct sockaddr_in *)&ifr.ifr_addr; + sin->sin_family = AF_INET; + sin->sin_addr = *addr; + sin->sin_len = sizeof(struct sockaddr_in); + + return if_ioctl(ctx, cmd, &ifr, sizeof(ifr)); +} + +int +if_address(unsigned char cmd, const struct ipv4_addr *ia) { + int err; + struct in_addr addr; + + if (cmd == RTM_DELADDR) { + addr.s_addr = ia->addr.s_addr; + err = if_ioctl_addr(ia->iface->ctx, ia->iface->name, &addr, SIOCDIFADDR); + if (err) { + logerr("%s: cannot delete address", __func__); + return -1; + } + + return 0; + } + + addr.s_addr = ia->addr.s_addr; + err = if_ioctl_addr(ia->iface->ctx, ia->iface->name, &addr, SIOCSIFADDR); + if (err) { + logerr("%s: cannot set address", __func__); + return -1; + } + + addr.s_addr = ia->mask.s_addr; + err = if_ioctl_addr(ia->iface->ctx, ia->iface->name, &addr, SIOCSIFNETMASK); + if (err) { + logerr("%s: cannot set network mask", __func__); + return -1; + } + + addr.s_addr = ia->brd.s_addr; + err = if_ioctl_addr(ia->iface->ctx, ia->iface->name, &addr, SIOCSIFBRDADDR); + if (err && errno != ENOTTY) { + /* We have to accept ENOTTY as a success state here because lwip doesn't + * accept setting a broadcast address, it's a computed value. + * About pfinet, we expect to get a ENOTTY only when it doesn't get an + * authorized user. Not possible here because in that case previous calls + * would fail and the code wouldn't reach here. + */ + logerr("%s: cannot set broadcast address", __func__); + return -1; + } + + return 0; +} + +int +if_addrflags(__unused const struct interface *ifp, __unused const struct in_addr *addr, + __unused const char *alias) { + /* Not supported. Set flags to 0 */ + return 0; +} +#endif + +#ifdef INET6 +int +if_address6(__unused unsigned char cmd, __unused const struct ipv6_addr *ia) { + /* TODO */ + return -1; +} + +int +if_getlifetime6(__unused struct ipv6_addr *addr) { + /* TODO */ + return -1; +} + +int +if_addrflags6(__unused const struct interface *ifp, __unused const struct in6_addr *addr, + __unused const char *alias) { + /* TODO */ + return -1; +} + +void +if_setup_inet6(__unused const struct interface *ifp) { + /* TODO */ +} + +int +if_applyra(__unused const struct ra *rap) { + /* TODO */ + return -1; +} +#endif + +#ifdef PRIVSEP +ssize_t +ps_root_os(__unused struct dhcpcd_ctx *ctx, __unused struct ps_msghdr *psm, __unused struct msghdr *msg, + __unused void **rdata, __unused size_t *rlen, __unused bool *free_data) { + /* TODO */ + return -1; +} +#endif + +int +os_init(void) { + /* Not needed for now */ + return 0; +} + +/* + * Initialize the given interface. + * Try to get its MAC address and index + */ +int +if_init(struct interface *ifp) { + struct ifreq ifr; + + memset(&ifr, 0, sizeof(ifr)); + strlcpy(ifr.ifr_name, ifp->name, IFNAMSIZ); + + /* Don't try to get HW address for loopback interfaces */ + if ((ifp->flags & IFF_LOOPBACK) == 0) { + if (ioctl(ifp->ctx->pf_inet_fd, SIOCGIFHWADDR, &ifr) == -1) { + logerr("%s: SIOCGIFHWADDR", ifp->name); + return -1; + } + memcpy(ifp->hwaddr, ifr.ifr_hwaddr.sa_data, ETH_HWADDR_LEN); + ifp->hwtype = ifr.ifr_hwaddr.sa_family; + ifp->hwlen = ifr.ifr_hwaddr.sa_len; + } + + if (ioctl(ifp->ctx->pf_inet_fd, SIOCGIFINDEX, &ifr) == -1) { + logerr("%s: SIOCGIFINDEX", ifp->name); + return -1; + } + ifp->index = (unsigned int)ifr.ifr_ifindex; + + return 0; +} + +int +if_opensockets_os(__unused struct dhcpcd_ctx *ctx) { + ctx->link_fd = -1; + + return 0; +} + +void +if_closesockets_os(__unused struct dhcpcd_ctx *ctx) { + /* Nothing to do, as link_fd is not initialized */ +} + +int +if_conf(__unused struct interface *ifp) { + /* Not needed for now */ + return 0; +} + +int +if_handlelink(__unused struct dhcpcd_ctx *ctx) { + /* No needed if link_fd is not initialized */ + return 0; +} + +int +if_setmac(__unused struct interface *ifp, __unused void *mac, __unused uint8_t maclen) { + errno = EOPNOTSUPP; + return -1; +} + +unsigned short +if_vlanid(__unused const struct interface *ifp) { + /* We don't support vlans for now */ + return 0; +} + +int +if_carrier(struct interface *ifp, __unused const void *ifadata) { + struct ifreq ifr; + + memset(&ifr, 0, sizeof(ifr)); + strlcpy(ifr.ifr_name, ifp->name, IFNAMSIZ); + + if (ioctl(ifp->ctx->pf_inet_fd, SIOCGIFFLAGS, &ifr) == -1) { + logerr("%s: SIOCGIFFLAGS", ifp->name); + return LINK_UNKNOWN; + } + + if (ifr.ifr_flags & IFF_RUNNING) + return LINK_UP; + + return LINK_DOWN; +} + +bool +if_ignore(__unused struct dhcpcd_ctx *ctx, __unused const char *ifname) { + /* + * Return `true` for interfaces we want dhcpcd to ignore. + * + * Other OSs use this to ignore taps, bridges, and other kinds of + * virtual interfaces. + * + * We don't use this for now. + */ + return false; +} + +int +if_machinearch(__unused char *str, __unused size_t len) { + /* + * dhcpcd already has uname info. + * We don't need to add extra architecture info for now. + */ + return 0; +} -- 2.50.1
