From 61089eace7d46c28d3e72abbe182f54762bda25f Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Fri, 10 Jul 2020 22:16:12 +0200 Subject: [PATCH] Keep track of interfaces and local addresses. --- src/discovery.c | 143 ++++++++++++++++++++++++++++++++++++++-- src/meshlink_internal.h | 4 ++ 2 files changed, 140 insertions(+), 7 deletions(-) diff --git a/src/discovery.c b/src/discovery.c index 34b49fa2..ece4fbe9 100644 --- a/src/discovery.c +++ b/src/discovery.c @@ -24,6 +24,7 @@ #include "discovery.h" #include "sockaddr.h" #include "logger.h" +#include "netutl.h" #include "node.h" #include "connection.h" #include "xalloc.h" @@ -91,7 +92,7 @@ static void discovery_create_services(meshlink_handle_t *mesh) { logger(mesh, MESHLINK_DEBUG, "Adding service\n"); - /* Ifthis is the first time we're called, let's create a new entry group */ + /* If this is the first time we're called, let's create a new entry group */ if(!(mesh->catta_group = catta_s_entry_group_new(mesh->catta_server, discovery_entry_group_callback, mesh))) { logger(mesh, MESHLINK_ERROR, "catta_entry_group_new() failed: %s\n", catta_strerror(catta_server_errno(mesh->catta_server))); goto fail; @@ -493,6 +494,113 @@ fail: return NULL; } +typedef struct discovery_address { + int index; + bool up; + sockaddr_t address; +} discovery_address_t; + +static int iface_compare(const void *va, const void *vb) { + const int *a = va; + const int *b = vb; + return *a - *b; +} + +static int address_compare(const void *va, const void *vb) { + const discovery_address_t *a = va; + const discovery_address_t *b = vb; + + if(a->index != b->index) { + return a->index - b->index; + } + + return sockaddrcmp_noport(&a->address, &b->address); +} + +static void send_mdns_packet(meshlink_handle_t *mesh, const discovery_address_t *addr) { + char *host = NULL, *port = NULL; + sockaddr2str(&addr->address, &host, &port); + fprintf(stderr, "Sending on iface %d %s port %s\n", addr->index, host, port); + free(host); + free(port); +} + +static void iface_up(meshlink_handle_t *mesh, int index) { + int *p = bsearch(&index, mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(*p), iface_compare); + + if(p) { + return; + } + + fprintf(stderr, "iface %d up\n", index); + mesh->discovery_ifaces = xrealloc(mesh->discovery_ifaces, ++mesh->discovery_iface_count * sizeof(*p)); + mesh->discovery_ifaces[mesh->discovery_iface_count - 1] = index; + qsort(mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(*p), iface_compare); + + for(int i = 0; i < mesh->discovery_iface_count; i++) { + fprintf(stderr, "%d", mesh->discovery_ifaces[i]); + } + + // Send an announcement for all addresses associated with this interface + for(int i = 0; i < mesh->discovery_address_count; i++) { + if(mesh->discovery_addresses[i].index == index) { + send_mdns_packet(mesh, &mesh->discovery_addresses[i]); + } + } +} + +static void iface_down(meshlink_handle_t *const mesh, int index) { + int *p = bsearch(&index, mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(int), iface_compare); + + if(!p) { + return; + } + + fprintf(stderr, "iface %d down\n", index); + memmove(p, p + 1, --mesh->discovery_iface_count * sizeof(*p)); +} + +static void addr_add(meshlink_handle_t *mesh, const discovery_address_t *addr) { + discovery_address_t *p = bsearch(addr, mesh->discovery_addresses, mesh->discovery_address_count, sizeof(int), address_compare); + + if(p) { + return; + } + + bool up = bsearch(&addr->index, mesh->discovery_ifaces, mesh->discovery_iface_count, sizeof(*p), iface_compare); + char *host = NULL, *port = NULL; + sockaddr2str(&addr->address, &host, &port); + fprintf(stderr, "address %d %s port %s up %d\n", addr->index, host, port, up); + free(host); + free(port); + + mesh->discovery_addresses = xrealloc(mesh->discovery_addresses, ++mesh->discovery_address_count * sizeof(*p)); + mesh->discovery_addresses[mesh->discovery_address_count - 1] = *addr; + qsort(mesh->discovery_addresses, mesh->discovery_address_count, sizeof(*p), address_compare); + + mesh->discovery_addresses[mesh->discovery_address_count - 1].up = up; + + if(up) { + send_mdns_packet(mesh, &mesh->discovery_addresses[mesh->discovery_address_count - 1]); + } +} + +static void addr_del(meshlink_handle_t *mesh, const discovery_address_t *addr) { + discovery_address_t *p = bsearch(addr, mesh->discovery_addresses, mesh->discovery_address_count, sizeof(*p), address_compare); + + if(!p) { + return; + } + + char *host = NULL, *port = NULL; + sockaddr2str(&addr->address, &host, &port); + fprintf(stderr, "address %d %s port %s down\n", addr->index, host, port); + free(host); + free(port); + + memmove(p, p + 1, --mesh->discovery_address_count * sizeof(*p)); +} + #if defined(__linux) static void netlink_getlink(int fd) { static const struct { @@ -522,13 +630,14 @@ static void netlink_getaddr(int fd) { send(fd, &msg, msg.nlm.nlmsg_len, 0); } + static void netlink_parse_link(meshlink_handle_t *mesh, const struct nlmsghdr *nlm) { const struct ifinfomsg *ifi = (const struct ifinfomsg *)(nlm + 1); if(ifi->ifi_flags & IFF_UP && ifi->ifi_flags & IFF_MULTICAST) { - logger(mesh, MESHLINK_INFO, "iface %d active\n", ifi->ifi_index); + iface_up(mesh, ifi->ifi_index); } else { - logger(mesh, MESHLINK_INFO, "iface %d inactive\n", ifi->ifi_index); + iface_down(mesh, ifi->ifi_index); } } @@ -545,15 +654,30 @@ static void netlink_parse_addr(meshlink_handle_t *mesh, const struct nlmsghdr *n } if(rta->rta_type == IFA_ADDRESS) { - char dest[40] = "?"; + discovery_address_t addr = { + .index = ifa->ifa_index, + }; if(rta->rta_len == 8) { - inet_ntop(AF_INET, ptr + 4, dest, sizeof dest); + addr.address.sa.sa_family = AF_INET; + memcpy(&addr.address.in.sin_addr, ptr + 4, 4); + addr.address.in.sin_port = 5353; } else if(rta->rta_len == 20) { - inet_ntop(AF_INET6, ptr + 4, dest, sizeof dest); + addr.address.sa.sa_family = AF_INET6; + memcpy(&addr.address.in6.sin6_addr, ptr + 4, 16); + addr.address.in6.sin6_port = 5353; + addr.address.in6.sin6_scope_id = ifa->ifa_index; + } else { + addr.address.sa.sa_family = AF_UNKNOWN; } - logger(mesh, MESHLINK_INFO, "iface %d address %s %s\n", ifa->ifa_index, dest, nlm->nlmsg_type == RTM_NEWADDR ? "new" : "del"); + if(addr.address.sa.sa_family != AF_UNKNOWN) { + if(nlm->nlmsg_type == RTM_NEWADDR) { + addr_add(mesh, &addr); + } else { + addr_del(mesh, &addr); + } + } } unsigned short rta_len = (rta->rta_len + 3) & ~3; @@ -742,6 +866,11 @@ void discovery_stop(meshlink_handle_t *mesh) { assert(mesh); + free(mesh->discovery_ifaces); + free(mesh->discovery_addresses); + mesh->discovery_iface_count = 0; + mesh->discovery_address_count = 0; + if(mesh->pfroute_io.cb) { close(mesh->pfroute_io.fd); io_del(&mesh->loop, &mesh->pfroute_io); diff --git a/src/meshlink_internal.h b/src/meshlink_internal.h index a092e1b6..127a9935 100644 --- a/src/meshlink_internal.h +++ b/src/meshlink_internal.h @@ -193,6 +193,10 @@ struct meshlink_handle { // PFROUTE io_t pfroute_io; + int *discovery_ifaces; + struct discovery_address *discovery_addresses; + int discovery_iface_count; + int discovery_address_count; // ADNS pthread_t adns_thread; -- 2.39.5