wireshark/capture/capture_ifinfo.c

/* capture_ifinfo.c
 * Routines for getting interface information from dumpcap
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"
#define WS_LOG_DOMAIN LOG_DOMAIN_CAPTURE

#ifdef HAVE_LIBPCAP

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include <glib.h>

#include "capture_opts.h"

#include "capture/capture_session.h"
#include "capture/capture_sync.h"
#include "extcap.h"

#include <capture/capture_ifinfo.h>
#include <wsutil/inet_addr.h>

#ifdef HAVE_PCAP_REMOTE
static GList *remote_interface_list = NULL;

static GList * append_remote_list(GList *iflist)
{
    GSList *list;
    GList *rlist;
    if_addr_t *if_addr, *temp_addr;
    if_info_t *if_info, *temp;

    for (rlist = g_list_nth(remote_interface_list, 0); rlist != NULL; rlist = g_list_next(rlist)) {
        if_info = (if_info_t *)rlist->data;
        temp = g_new0(if_info_t, 1);
        temp->name = g_strdup(if_info->name);
        temp->friendly_name = g_strdup(if_info->friendly_name);
        temp->vendor_description = g_strdup(if_info->vendor_description);
        for (list = g_slist_nth(if_info->addrs, 0); list != NULL; list = g_slist_next(list)) {
            temp_addr = g_new0(if_addr_t, 1);
            if_addr = (if_addr_t *)list->data;
            if (if_addr) {
                temp_addr->ifat_type = if_addr->ifat_type;
                if (temp_addr->ifat_type == IF_AT_IPv4) {
                    temp_addr->addr.ip4_addr = if_addr->addr.ip4_addr;
                } else {
                    memcpy(temp_addr->addr.ip6_addr, if_addr->addr.ip6_addr, sizeof(if_addr->addr));
                }
            } else {
                g_free(temp_addr);
                temp_addr = NULL;
            }
            if (temp_addr) {
                temp->addrs = g_slist_append(temp->addrs, temp_addr);
            }
        }
        temp->loopback = if_info->loopback;
        iflist = g_list_append(iflist, temp);
   }
   return iflist;
}
#endif

/**
 * Fetch the interface list from a child process (dumpcap).
 *
 * @return A GList containing if_info_t structs if successful, NULL (with err and possibly err_str set) otherwise.
 *
 */

/* XXX - We parse simple text output to get our interface list.  Should
 * we use "real" data serialization instead, e.g. via XML? */
GList *
capture_interface_list(int *err, char **err_str, void (*update_cb)(void))
{
    int        ret;
    GList     *if_list = NULL;
    int        i, j;
    gchar     *data, *primary_msg, *secondary_msg;
    gchar    **raw_list, **if_parts, **addr_parts;
    gchar     *name;
    if_info_t *if_info;
    if_addr_t *if_addr;

    *err = 0;
    if (err_str) {
        *err_str = NULL;
    }

    /* Try to get our interface list */
    ret = sync_interface_list_open(&data, &primary_msg, &secondary_msg, update_cb);
    if (ret != 0) {
        /* Add the extcap interfaces that can exist, even if no native interfaces have been found */
        ws_info("Loading External Capture Interface List ...");
        if_list = append_extcap_interface_list(if_list, err_str);
        /* err_str is ignored, as the error for the interface loading list will take precedence */
        if ( g_list_length(if_list) == 0 ) {

            ws_info("Capture Interface List failed. Error %d, %s (%s)",
                  *err, primary_msg ? primary_msg : "no message",
                  secondary_msg ? secondary_msg : "no secondary message");
            if (err_str) {
                *err_str = primary_msg;
            } else {
                g_free(primary_msg);
            }
            g_free(secondary_msg);
            *err = CANT_GET_INTERFACE_LIST;

        }
        return if_list;
    }

    /* Split our lines */
#ifdef _WIN32
    raw_list = g_strsplit(data, "\r\n", 0);
#else
    raw_list = g_strsplit(data, "\n", 0);
#endif
    g_free(data);

    for (i = 0; raw_list[i] != NULL; i++) {
        if_parts = g_strsplit(raw_list[i], "\t", 7);
        if (if_parts[0] == NULL || if_parts[1] == NULL || if_parts[2] == NULL ||
                if_parts[3] == NULL || if_parts[4] == NULL || if_parts[5] == NULL ||
                if_parts[6] == NULL) {
            g_strfreev(if_parts);
            continue;
        }

        /* Number followed by the name, e.g "1. eth0" */
        name = strchr(if_parts[0], ' ');
        if (name) {
            name++;
        } else {
            g_strfreev(if_parts);
            continue;
        }

        if_info = g_new0(if_info_t,1);
        if_info->name = g_strdup(name);
        if (strlen(if_parts[1]) > 0)
            if_info->vendor_description = g_strdup(if_parts[1]);
        if (strlen(if_parts[2]) > 0)
            if_info->friendly_name = g_strdup(if_parts[2]);
        if_info->type = (interface_type)(int)strtol(if_parts[3], NULL, 10);
        addr_parts = g_strsplit(if_parts[4], ",", 0);
        for (j = 0; addr_parts[j] != NULL; j++) {
            if_addr = g_new0(if_addr_t,1);
            if (ws_inet_pton4(addr_parts[j], &if_addr->addr.ip4_addr)) {
                if_addr->ifat_type = IF_AT_IPv4;
            } else if (ws_inet_pton6(addr_parts[j], (ws_in6_addr *)&if_addr->addr.ip6_addr)) {
                if_addr->ifat_type = IF_AT_IPv6;
            } else {
                g_free(if_addr);
                if_addr = NULL;
            }
            if (if_addr) {
                if_info->addrs = g_slist_append(if_info->addrs, if_addr);
            }
        }
        if (strcmp(if_parts[5], "loopback") == 0)
            if_info->loopback = TRUE;
        if_info->extcap = g_strdup(if_parts[6]);
        g_strfreev(if_parts);
        g_strfreev(addr_parts);
        if_list = g_list_append(if_list, if_info);
    }
    g_strfreev(raw_list);

#ifdef HAVE_PCAP_REMOTE
    if (remote_interface_list && g_list_length(remote_interface_list) > 0) {
        if_list = append_remote_list(if_list);
    }
#endif

    /* Add the extcap interfaces after the native and remote interfaces */
    ws_info("Loading External Capture Interface List ...");
    if_list = append_extcap_interface_list(if_list, err_str);

    return if_list;
}

/* XXX - We parse simple text output to get our interface list.  Should
 * we use "real" data serialization instead, e.g. via XML? */
if_capabilities_t *
capture_get_if_capabilities(const gchar *ifname, gboolean monitor_mode,
                            const gchar *auth_string,
                            char **err_primary_msg, char **err_secondary_msg,
                            void (*update_cb)(void))
{
    if_capabilities_t *caps;
    GList              *linktype_list = NULL, *timestamp_list = NULL;
    int                 err, i;
    gchar              *data, *primary_msg, *secondary_msg;
    gchar             **raw_list;

    /* see if the interface is from extcap */
    caps = extcap_get_if_dlts(ifname, err_primary_msg);
    if (caps != NULL)
        return caps;

    /* return if the extcap interface generated an error */
    if (err_primary_msg != NULL && *err_primary_msg != NULL)
        return NULL;

    /* Try to get our interface list */
    err = sync_if_capabilities_open(ifname, monitor_mode, auth_string, &data,
                                    &primary_msg, &secondary_msg, update_cb);
    if (err != 0) {
        ws_info("Capture Interface Capabilities failed. Error %d, %s",
              err, primary_msg ? primary_msg : "no message");
        if (err_primary_msg)
            *err_primary_msg = primary_msg;
        else
            g_free(primary_msg);
        if (err_secondary_msg)
            *err_secondary_msg = secondary_msg;
        else
            g_free(secondary_msg);
        return NULL;
    }

    /* Split our lines */
#ifdef _WIN32
    raw_list = g_strsplit(data, "\r\n", 0);
#else
    raw_list = g_strsplit(data, "\n", 0);
#endif
    g_free(data);

    /*
     * First line is 0 if monitor mode isn't supported, 1 if it is.
     */
    if (raw_list[0] == NULL || *raw_list[0] == '\0') {
        ws_info("Capture Interface Capabilities returned no information.");
        if (err_primary_msg) {
            *err_primary_msg = g_strdup("Dumpcap returned no interface capability information");
        }
        g_strfreev(raw_list);
        return NULL;
    }

    /*
     * Allocate the interface capabilities structure.
     */
    caps = (if_capabilities_t *)g_malloc(sizeof *caps);
    switch (*raw_list[0]) {

    case '0':
        caps->can_set_rfmon = FALSE;
        break;

    case '1':
        caps->can_set_rfmon = TRUE;
        break;

    default:
        ws_info("Capture Interface Capabilities returned bad information.");
        if (err_primary_msg) {
            *err_primary_msg = ws_strdup_printf("Dumpcap returned \"%s\" for monitor-mode capability",
                                       raw_list[0]);
        }
        g_free(caps);
        g_strfreev(raw_list);
        return NULL;
    }

    /*
     * The following are link-layer types.
     */
    for (i = 1; raw_list[i] != NULL && *raw_list[i] != '\0'; i++) {
        data_link_info_t *data_link_info;
        /* ...and what if the interface name has a tab in it, Mr. Clever Programmer? */
        char **lt_parts = g_strsplit(raw_list[i], "\t", 3);
        if (lt_parts[0] == NULL || lt_parts[1] == NULL || lt_parts[2] == NULL) {
            g_strfreev(lt_parts);
            continue;
        }

        data_link_info = g_new(data_link_info_t,1);
        data_link_info->dlt = (int) strtol(lt_parts[0], NULL, 10);
        data_link_info->name = g_strdup(lt_parts[1]);
        if (strcmp(lt_parts[2], "(not supported)") != 0)
            data_link_info->description = g_strdup(lt_parts[2]);
        else
            data_link_info->description = NULL;
        g_strfreev(lt_parts);

        linktype_list = g_list_append(linktype_list, data_link_info);
    }

    if (raw_list[i]) { /* Oh, timestamp types! */
        for (i++; raw_list[i] != NULL && *raw_list[i] != '\0'; i++) {
            timestamp_info_t *timestamp_info;
            char **tt_parts = g_strsplit(raw_list[i], "\t", 2);
            if (tt_parts[0] == NULL || tt_parts[1] == NULL) {
                g_strfreev(tt_parts);
                continue;
            }

            timestamp_info = g_new(timestamp_info_t,1);
            timestamp_info->name = g_strdup(tt_parts[0]);
            timestamp_info->description = g_strdup(tt_parts[1]);
            g_strfreev(tt_parts);

            timestamp_list = g_list_append(timestamp_list, timestamp_info);
        }
    }

    g_strfreev(raw_list);

    caps->data_link_types = linktype_list;
    /* Might be NULL. Not all systems report timestamp types */
    caps->timestamp_types = timestamp_list;

    return caps;
}

#ifdef HAVE_PCAP_REMOTE
void add_interface_to_remote_list(if_info_t *if_info)
{
    GSList *list;
    if_addr_t *if_addr, *temp_addr;

    if_info_t *temp = g_new0(if_info_t, 1);
    temp->name = g_strdup(if_info->name);
    temp->friendly_name = g_strdup(if_info->friendly_name);
    temp->vendor_description = g_strdup(if_info->vendor_description);
    for (list = g_slist_nth(if_info->addrs, 0); list != NULL; list = g_slist_next(list)) {
        temp_addr = g_new0(if_addr_t, 1);
        if_addr = (if_addr_t *)list->data;
        if (if_addr) {
            temp_addr->ifat_type = if_addr->ifat_type;
            if (temp_addr->ifat_type == IF_AT_IPv4) {
                temp_addr->addr.ip4_addr = if_addr->addr.ip4_addr;
            } else {
                memcpy(temp_addr->addr.ip6_addr, if_addr->addr.ip6_addr, sizeof(if_addr->addr));
            }
        } else {
            g_free(temp_addr);
            temp_addr = NULL;
        }
        if (temp_addr) {
            temp->addrs = g_slist_append(temp->addrs, temp_addr);
        }
    }
    temp->loopback = if_info->loopback;
    remote_interface_list = g_list_append(remote_interface_list, temp);
}
#endif
#endif /* HAVE_LIBPCAP */