wpa_ctrl.c

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#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/time.h>
#ifndef CONFIG_NATIVE_WINDOWS
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/un.h>
#endif /* CONFIG_NATIVE_WINDOWS */

#include "wpa_ctrl.h"
#ifdef CONFIG_NATIVE_WINDOWS
#include "common.h"
#endif /* CONFIG_NATIVE_WINDOWS */


struct wpa_ctrl {
        int s;
#ifdef CONFIG_CTRL_IFACE_UDP
        struct sockaddr_in local;
        struct sockaddr_in dest;
#else /* CONFIG_CTRL_IFACE_UDP */
        struct sockaddr_un local;
        struct sockaddr_un dest;
#endif /* CONFIG_CTRL_IFACE_UDP */
};


struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
{
        struct wpa_ctrl *ctrl;
#ifndef CONFIG_CTRL_IFACE_UDP
        static int counter = 0;
#endif /* CONFIG_CTRL_IFACE_UDP */

        ctrl = malloc(sizeof(*ctrl));
        if (ctrl == NULL)
                return NULL;
        memset(ctrl, 0, sizeof(*ctrl));

#ifdef CONFIG_CTRL_IFACE_UDP
        ctrl->s = socket(PF_INET, SOCK_DGRAM, 0);
        if (ctrl->s < 0) {
                perror("socket");
                free(ctrl);
                return NULL;
        }

        ctrl->local.sin_family = AF_INET;
        ctrl->local.sin_addr.s_addr = htonl((127 << 24) | 1);
        if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
                 sizeof(ctrl->local)) < 0) {
                close(ctrl->s);
                free(ctrl);
                return NULL;
        }

        ctrl->dest.sin_family = AF_INET;
        ctrl->dest.sin_addr.s_addr = htonl((127 << 24) | 1);
        ctrl->dest.sin_port = htons(WPA_CTRL_IFACE_PORT);
        if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
                    sizeof(ctrl->dest)) < 0) {
                perror("connect");
                close(ctrl->s);
                free(ctrl);
                return NULL;
        }
#else /* CONFIG_CTRL_IFACE_UDP */
        ctrl->s = socket(PF_UNIX, SOCK_DGRAM, 0);
        if (ctrl->s < 0) {
                free(ctrl);
                return NULL;
        }

        ctrl->local.sun_family = AF_UNIX;
        snprintf(ctrl->local.sun_path, sizeof(ctrl->local.sun_path),
                 "/tmp/wpa_ctrl_%d-%d", getpid(), counter++);
        if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
                    sizeof(ctrl->local)) < 0) {
                close(ctrl->s);
                free(ctrl);
                return NULL;
        }

        ctrl->dest.sun_family = AF_UNIX;
        snprintf(ctrl->dest.sun_path, sizeof(ctrl->dest.sun_path), "%s",
                 ctrl_path);
        if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
                    sizeof(ctrl->dest)) < 0) {
                close(ctrl->s);
                unlink(ctrl->local.sun_path);
                free(ctrl);
                return NULL;
        }
#endif /* CONFIG_CTRL_IFACE_UDP */

        return ctrl;
}


void wpa_ctrl_close(struct wpa_ctrl *ctrl)
{
#ifndef CONFIG_CTRL_IFACE_UDP
        unlink(ctrl->local.sun_path);
#endif /* CONFIG_CTRL_IFACE_UDP */
        close(ctrl->s);
        free(ctrl);
}


int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
                     char *reply, size_t *reply_len,
                     void (*msg_cb)(char *msg, size_t len))
{
        struct timeval tv;
        int res;
        fd_set rfds;

        if (send(ctrl->s, cmd, cmd_len, 0) < 0)
                return -1;

        for (;;) {
                tv.tv_sec = 2;
                tv.tv_usec = 0;
                FD_ZERO(&rfds);
                FD_SET(ctrl->s, &rfds);
                res = select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
                if (FD_ISSET(ctrl->s, &rfds)) {
                        res = recv(ctrl->s, reply, *reply_len, 0);
                        if (res < 0)
                                return res;
                        if (res > 0 && reply[0] == '<') {
                                /* This is an unsolicited message from
                                 * wpa_supplicant, not the reply to the
                                 * request. Use msg_cb to report this to the
                                 * caller. */
                                if (msg_cb) {
                                        /* Make sure the message is nul
                                         * terminated. */
                                        if ((size_t) res == *reply_len)
                                                res = (*reply_len) - 1;
                                        reply[res] = '\0';
                                        msg_cb(reply, res);
                                }
                                continue;
                        }
                        *reply_len = res;
                        break;
                } else {
                        return -2;
                }
        }
        return 0;
}


static int wpa_ctrl_attach_helper(struct wpa_ctrl *ctrl, int attach)
{
        char buf[10];
        int ret;
        size_t len = 10;

        ret = wpa_ctrl_request(ctrl, attach ? "ATTACH" : "DETACH", 6,
                               buf, &len, NULL);
        if (ret < 0)
                return ret;
        if (len == 3 && memcmp(buf, "OK\n", 3) == 0)
                return 0;
        return -1;
}


int wpa_ctrl_attach(struct wpa_ctrl *ctrl)
{
        return wpa_ctrl_attach_helper(ctrl, 1);
}


int wpa_ctrl_detach(struct wpa_ctrl *ctrl)
{
        return wpa_ctrl_attach_helper(ctrl, 0);
}


int wpa_ctrl_recv(struct wpa_ctrl *ctrl, char *reply, size_t *reply_len)
{
        int res;

        res = recv(ctrl->s, reply, *reply_len, 0);
        if (res < 0)
                return res;
        *reply_len = res;
        return 0;
}


int wpa_ctrl_pending(struct wpa_ctrl *ctrl)
{
        struct timeval tv;
        int res;
        fd_set rfds;
        tv.tv_sec = 0;
        tv.tv_usec = 0;
        FD_ZERO(&rfds);
        FD_SET(ctrl->s, &rfds);
        res = select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
        return FD_ISSET(ctrl->s, &rfds);
}


int wpa_ctrl_get_fd(struct wpa_ctrl *ctrl)
{
        return ctrl->s;
}

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