wpa_event_listener: adds the Morse Micro supplicant event listener

This package is used to capture events emitted from wpa_supplicant,
primarily designed for managing DPP push button events

utils/wpa_event_listener/Makefile

@@ -0,0 +1,33 @@
+#
+# Copyright 2023 Morse Micro
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=wpa_event_listener
+PKG_RELEASE:=1
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/wpa_event_listener
+  SECTION:=utils
+  CATEGORY:=Base system
+  TITLE:= WPA supplicant s1g event listener
+  MAINTAINER:=Morse Micro
+  DEPENDS:= wpa_supplicant_s1g +libwpa_client
+endef
+
+define Package/wpa_event_listener/description
+ A Daemon to listen to wpa supplicant s1g events.
+endef
+
+define Package/wpa_event_listener/install
+	$(INSTALL_DIR) $(1)/usr/sbin
+
+	$(INSTALL_BIN) $(PKG_BUILD_DIR)/wpa_event_listener 	$(1)/usr/sbin
+endef
+
+$(eval $(call BuildPackage,wpa_event_listener))

utils/wpa_event_listener/src/Makefile

@@ -0,0 +1,24 @@
+#
+# Copyright (C) 2023-2024 Morse Micro Pty Ltd. All rights reserved
+#
+APP=wpa_event_listener
+
+LDFLAGS+=-lwpa_client -lubox
+
+ODIR=build
+
+_OBJ = wpa_event_listener.o
+OBJ = $(patsubst %,$(ODIR)/%,$(_OBJ))
+
+
+$(ODIR)/%.o: %.c
+	mkdir $(ODIR) -p
+	$(CC) -c -o $@ $< $(CFLAGS)
+
+$(APP): $(OBJ)
+	$(CC) -o $@ $^ $(CFLAGS) $(LDFLAGS)
+
+.PHONY: clean
+
+clean:
+	rm -rf $(ODIR) $(APP)

utils/wpa_event_listener/src/wpa_event_listener.c

@@ -0,0 +1,401 @@
+/*
+ *  copyright (C) 2023-2024 Morse Micro Pty Ltd. All rights reserved.
+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <libubox/uloop.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <wpa_ctrl.h>
+
+#define CONFIG_CTRL_IFACE_DIR "/var/run/wpa_supplicant_s1g"
+#define wpa_el_version "V1.0.0"
+
+enum event_value_types {
+    TYPE_CONF_RECEIVED,
+    TYPE_ENCRYPTION,
+    TYPE_SSID,
+    TYPE_PSK,
+    TYPE_CONNECTOR,
+    TYPE_C_SIGN_KEY,
+    TYPE_PP_KEY,
+    TYPE_NET_ACCESS_KEY,
+    TYPE_CTRL_EVENT_TERMINATING,
+    TYPE_PB_RESULT,
+    TYPE_PB_STATUS,
+};
+
+struct event {
+    const char *const event_title;
+    const enum event_value_types event_type;
+};
+
+/* dpp connector, c-sign-key, pp-key and net access key will be received after
+ * qrcode provisionning but they are ignored by now.
+ */
+static struct event interresting_events[] = {
+    {"DPP-CONF-RECEIVED", TYPE_CONF_RECEIVED},
+    {"DPP-CONFOBJ-AKM", TYPE_ENCRYPTION},
+    {"DPP-CONFOBJ-SSID", TYPE_SSID},
+    {"DPP-CONFOBJ-PASS", TYPE_PSK},
+    // { "DPP-CONNECTOR"       , TYPE_CONNECTOR },
+    // { "DPP-C-SIGN-KEY"      , TYPE_C_SIGN_KEY },
+    // { "DPP-PP-KEY"          , TYPE_PP_KEY },
+    // { "DPP-NET-ACCESS-KEY"  , TYPE_NET_ACCESS_KEY },
+    {"DPP-PB-STATUS", TYPE_PB_STATUS},
+    {"DPP-PB-RESULT", TYPE_PB_RESULT},
+    {"CTRL-EVENT-TERMINATING", TYPE_CTRL_EVENT_TERMINATING},
+};
+
+static struct {
+    char *encryption;
+    char *ssid;
+    char *psk;
+    // char* connector;
+    // char* c_sign_key;
+    // char* pp_key;
+    // char* net_access_key;
+} cached_confs;
+
+static struct wpa_ctrl *ctrl_conn;
+static struct uloop_fd listener;
+
+static void led_timeout_cb(struct uloop_timeout*);
+static struct uloop_timeout led_timeout = {
+    .cb = led_timeout_cb,
+};
+static void led_failed_cb(struct uloop_timeout *);
+static struct uloop_timeout failed_timeout = {
+    .cb = led_failed_cb,
+};
+
+static char *ctrl_ifname = NULL;
+static char *action_script = NULL;
+static const char *ctrl_iface_dir = CONFIG_CTRL_IFACE_DIR;
+static const char *pid_file = NULL;
+static int exit_on_config_receive = 1;
+
+void cache_received_confs(char **config, const char *const value) {
+    // check if the config is already allocated.
+    if (*config)
+        free(*config);
+    *config = strdup(value);
+}
+
+void clean_pointer(char **ptr) {
+    if (*ptr) {
+        free(*ptr);
+        *ptr = NULL;
+    }
+}
+
+void clear_cached_confs() {
+    clean_pointer(&cached_confs.encryption);
+    clean_pointer(&cached_confs.ssid);
+    clean_pointer(&cached_confs.psk);
+}
+
+void clear_env() {
+    unsetenv("iface_name");
+    unsetenv("encryption");
+    unsetenv("ssid");
+    unsetenv("psk");
+}
+
+void apply_cached_confs() {
+    // make sure that all needed configs are cached.
+    if (!cached_confs.encryption || !cached_confs.ssid || !cached_confs.psk)
+        return;
+
+    printf("Configs: \n");
+    printf("    encryption: %s\n", cached_confs.encryption);
+    printf("    ssid: %s\n", cached_confs.ssid);
+    printf("    psk: %s\n", cached_confs.psk);
+
+    pid_t pid = 0;
+    // only fork if we don't want to exit after receiving configs.
+    if (exit_on_config_receive == 0) {
+        pid = fork();
+        if (pid == -1) {
+            printf("Unable to fork action script\n");
+            return;
+        }
+        // forked process will have pid=0.
+        if (pid > 0)
+            return;
+    }
+
+    setenv("iface_name", ctrl_ifname, 1);
+    setenv("encryption", cached_confs.encryption, 1);
+    setenv("ssid", cached_confs.ssid, 1);
+    setenv("psk", cached_confs.psk, 1);
+    if (execl(action_script, action_script, "config", (char *)NULL) == -1) {
+        perror("Could not execv");
+        clear_env();
+        return;
+    }
+    clear_env();
+}
+
+void call_action_script(const char *arg) {
+    pid_t pid = fork();
+    if (pid == -1) {
+        printf("Unable to fork action script");
+        return;
+    }
+    if (pid > 0) {
+        int status;
+        waitpid(pid, &status, 0);
+    } else if (execl(action_script, action_script, arg, (char *)NULL) == -1) {
+        perror("Could not execv");
+        exit(1);
+    }
+}
+
+static void led_timeout_cb(struct uloop_timeout *t) {
+    printf("led timeout\n");
+    call_action_script("finished");
+}
+
+static void led_finished() {
+    // Stop the blink.
+    printf("Stopping led blink\n");
+    uloop_timeout_cancel(&led_timeout);
+    call_action_script("finished");
+}
+
+static void led_failed_cb(struct uloop_timeout *t) {
+    // Start the fail blink with a short timeout.
+    printf("Starting led fail blink\n");
+    uloop_timeout_set(&led_timeout, 5000);
+    call_action_script("failed");
+}
+
+static void led_failed() {
+    // Issue the failed command after a small delay. This is because
+    // wpa_supplicant emits back to back failed and started events when a
+    // dpp_push_button occurs while another is still running, so save some time
+    // for led_started to cancel the failed_timeout.
+    uloop_timeout_set(&failed_timeout, 1000);
+}
+
+static void led_started() {
+    // Start the blink. Set a long timeout for the blink in case we don't see hostapd PB_RESULT event.
+    printf("Starting led blink\n");
+    uloop_timeout_cancel(&failed_timeout);
+    uloop_timeout_set(&led_timeout, 120000);
+    call_action_script("started");
+}
+
+static void message_process(char *const message) {
+    const int good_events_count = sizeof(interresting_events) / sizeof(struct event);
+
+    for (int i = 0; i < good_events_count; i++) {
+        char *ptr = strstr(message, interresting_events[i].event_title);
+        if (ptr) {
+            const char *const value = ptr + strlen(interresting_events[i].event_title) +
+                                      1; // 1 for the space between title and value
+            switch (interresting_events[i].event_type) {
+            case TYPE_CONF_RECEIVED:
+                clear_cached_confs();
+                break;
+            case TYPE_ENCRYPTION:
+                cache_received_confs(&cached_confs.encryption, value);
+                break;
+            case TYPE_SSID:
+                cache_received_confs(&cached_confs.ssid, value);
+                break;
+            case TYPE_PSK:
+                cache_received_confs(&cached_confs.psk, value);
+                break;
+            case TYPE_PB_RESULT:
+                // AP side we wont have confs, so apply_cached_confs does nothing.
+                if (strstr(value, "success")) {
+                    led_finished();
+                    apply_cached_confs();
+                    clear_cached_confs();
+                } else if (strstr(value, "failed")) {
+                    led_failed();
+                }
+                break;
+            case TYPE_PB_STATUS:
+                if (strcmp(value, "started") == 0) {
+                    led_started();
+                }
+                break;
+            case TYPE_CTRL_EVENT_TERMINATING:
+                printf("Connection to wpa_supplicant lost - exiting\n");
+                uloop_end();
+                break;
+            default:
+                break;
+            }
+            return;
+        }
+    }
+}
+
+static void listener_cb(struct uloop_fd *fd, unsigned int events) {
+    while (wpa_ctrl_pending(ctrl_conn) > 0) {
+        char buf[4096];
+        size_t len = sizeof(buf) - 1;
+        if (wpa_ctrl_recv(ctrl_conn, buf, &len) == 0) {
+            buf[len] = '\0';
+            printf("New Message:%s\n", buf);
+            message_process(buf);
+        } else {
+            printf("Could not read pending message.\n");
+            break;
+        }
+    }
+    if (wpa_ctrl_pending(ctrl_conn) < 0) {
+        printf("Connection to wpa_supplicant lost - exiting\n");
+        uloop_end();
+    }
+}
+
+static char *wpa_cli_get_default_ifname(void) {
+    char *ifname = NULL;
+
+    struct dirent *dent;
+    DIR *dir = opendir(ctrl_iface_dir);
+    if (!dir) {
+        return NULL;
+    }
+    while ((dent = readdir(dir))) {
+#ifdef _DIRENT_HAVE_D_TYPE
+        /*
+         * Skip the file if it is not a socket. Also accept
+         * DT_UNKNOWN (0) in case the C library or underlying
+         * file system does not support d_type.
+         */
+        if (dent->d_type != DT_SOCK && dent->d_type != DT_UNKNOWN)
+            continue;
+#endif /* _DIRENT_HAVE_D_TYPE */
+        /* Skip current/previous directory and special P2P Device
+         * interfaces. */
+        if (strcmp(dent->d_name, ".") == 0 || strcmp(dent->d_name, "..") == 0 ||
+            strncmp(dent->d_name, "p2p-dev-", 8) == 0)
+            continue;
+        printf("Selected interface '%s'\n", dent->d_name);
+        ifname = strdup(dent->d_name);
+        break;
+    }
+    closedir(dir);
+
+    return ifname;
+}
+
+static void usage(void) {
+    printf("wpa_event_listener  [-p<path to ctrl socket dir>] -i<ifname> [-hvBN] "
+           "-a<action file> \\\n"
+           "                    [-P<pid file>] "
+           "\\\n"
+           "        "
+           "  -h = help (show this usage text)\n"
+           "  -v = shown version information\n"
+           "  -N = No Exit: don't exit after the configs are received.\n"
+           "  -a = run in daemon mode executing the action file based on "
+           "events from\n"
+           "  -B = run a daemon in the background\n"
+           "  default path: " CONFIG_CTRL_IFACE_DIR "\n"
+           "  default interface: first interface found in socket path\n");
+}
+
+int main(int argc, char *argv[]) {
+    int c;
+    int daemonize = 0;
+    for (;;) {
+        c = getopt(argc, argv, "a:Bg:G:hNi:p:P:rs:v");
+        if (c < 0)
+            break;
+        switch (c) {
+        case 'a':
+            action_script = optarg;
+            break;
+        case 'B':
+            daemonize = 1;
+            break;
+        case 'h':
+            usage();
+            return 0;
+        case 'v':
+            printf("%s\n", wpa_el_version);
+            return 0;
+        case 'i':
+            ctrl_ifname = strdup(optarg);
+            break;
+        case 'p':
+            ctrl_iface_dir = optarg;
+            break;
+        case 'P':
+            pid_file = optarg;
+            break;
+        case 'N':
+            printf("No exit after receive config.\n");
+            exit_on_config_receive = 0;
+            break;
+        default:
+            usage();
+            return -1;
+        }
+    }
+
+    if (ctrl_ifname == NULL)
+        ctrl_ifname = wpa_cli_get_default_ifname();
+    if (ctrl_ifname == NULL) {
+        printf("No WPA supplicant ctrl interface found.\n");
+        return -1;
+    }
+
+    if (daemonize) {
+        if (!action_script) {
+            printf("Daemonizing requires an action script.\n");
+            return -1;
+        }
+
+        if (daemon(0, 0)) {
+            perror("daemon");
+            return -1;
+        }
+        if (pid_file) {
+            FILE *f = fopen(pid_file, "w");
+            if (f) {
+                fprintf(f, "%u\n", getpid());
+                fclose(f);
+            }
+        }
+    }
+
+    char *path = malloc(strlen(ctrl_iface_dir) + strlen(ctrl_ifname) + 2);
+    sprintf(path, "%s/%s", ctrl_iface_dir, ctrl_ifname);
+
+    if (!(ctrl_conn = wpa_ctrl_open(path))) {
+        printf("unable to open control interface on %s.\n", path);
+        return -1;
+    }
+
+    uloop_init();
+
+    if (wpa_ctrl_attach(ctrl_conn) == 0) {
+        listener.cb = listener_cb;
+        listener.fd = wpa_ctrl_get_fd(ctrl_conn);
+        uloop_fd_add(&listener, ULOOP_READ);
+        listener_cb(NULL, 0);
+    } else {
+        printf("Failed to attach to wpa_supplicant.\n");
+        wpa_ctrl_close(ctrl_conn);
+        return -1;
+    }
+
+    uloop_run();
+    printf("Exiting\n");
+    if (pid_file)
+        remove(pid_file);
+
+    return 0;
+}