Callbacks

Control Area Network - Ethernet - Gateway - Control (Utility) More...

Collaboration diagram for Callbacks:

Functions
int	main (int argc, char *argv[])
	creates an Ethernet package and sends it to a device. More...
int	nl_cb_general_errno (struct sockaddr_nl *nla, struct nlmsgerr *nlerr, void *arg)
	A callback wich prints the errno to stderr. More...
int	nl_cb_list_entry (struct nl_msg *msg, void *arg)
	will be called for every multipart message and prints informations to stdout. More...
int	nl_cb_list_finish (struct nl_msg *msg, void *arg)
	will be called at the end of a multipart message. More...
int	nl_cb_echo_answer (struct nl_msg *msg, void *arg)
	Callback witch receive the message sen bach by kernel. More...

Variables
int	verbose_flag
int	bidirectional_flag = 0
uint32_t	flags = 0
uint8_t	gw_type = TYPE_NET

Detailed Description

Control Area Network - Ethernet - Gateway - Control (Utility)

The gateway is configured here.

Function Documentation

int main	(	int	argc,
		char *	argv[]
	)

creates an Ethernet package and sends it to a device.

Parameters

argc	counts the arguments from the console param argv each word from the console is written down in this array

Returns

EXIT_SUCCESS if the program was succesful, EXIT_FAILURE if an error occured

Definition at line 48 of file main.c.

References bidirectional_flag, ce_gw_add(), ce_gw_del(), ce_gw_echo(), ce_gw_list(), F_CAN_FD, nl_sk_fam_exit(), nl_sk_fam_init(), TYPE_ETH, TYPE_NET, TYPE_NONE, TYPE_TCP, TYPE_UDP, and verbose_flag.

{
    int err = 0;

    err = nl_sk_fam_init();
    if (err != 0) {
        fprintf(stderr,
                "Error during initialisation of Socket or Netlink "
                "Family: %d\n", err);
        return EXIT_FAILURE;
    }

    int c;

    while (1) {
        static struct option long_options[] = {
            /* These options set a flag. */

            /* These options don't set a flag.
               We distinguish them by their indices. */
            {"bidirectional", no_argument, 0, 'b'},
            {"can-fd",        no_argument, 0, 'f'},
            {"type",    required_argument, 0, 't'},
            {0, 0, 0, 0},
        };
        /* getopt_long stores the option index here. */
        int option_index = 0;

        c = getopt_long (argc, argv, "bft:",
                         long_options, &option_index);

        /* Detect the end of the options. */
        if (c == -1)
            break;

        switch (c) {
        case 0:
            /* If this option set a flag, do nothing else now. */
            if (long_options[option_index].flag != 0)
                break;
            printf ("option %s", long_options[option_index].name);

            if (optarg)
                printf (" with arg %s", optarg);
            printf ("\n");
            break;

        case 'b':
            bidirectional_flag = 1;
            break;

        case 'f':
            flags = flags | F_CAN_FD;
            break;

        case 't':
            if(!strcmp(optarg, "none")) {
                gw_type = TYPE_NONE;
            } else if(!strcmp(optarg, "eth")) {
                gw_type = TYPE_ETH;
            } else if (!strcmp(optarg, "net")) {
                gw_type = TYPE_NET;
            } else if (!strcmp(optarg, "tcp")) {
                gw_type = TYPE_TCP;
            } else if (!strcmp(optarg, "udp")) {
                gw_type = TYPE_UDP;
            } else {
                fprintf(stderr, "%s: Supported Types: "
                        "none, eth, net, tcp, udp\n", argv[0]);
                return EXIT_FAILURE;
            }

            break;

        case '?':
            /* getopt_long already printed an error message. */
            break;

        default:
            abort();
        }
    }

    /* Instead of reporting ‘--verbose’
       and ‘--brief’ as they are encountered,
       we report the final status resulting from them. */
    if (verbose_flag)
        puts ("verbose flag is set\n");


    /***************************************************/
    /* Remaining command line arguments (not options). */
    /***************************************************/
    while (optind < argc) {

        /* add route SRC DST */
        if(!strcmp(argv[optind], "add") &&
            !strcmp(argv[optind+1], "route") && optind+4 <= argc) {

            err = ce_gw_add(argv[optind+3], argv[optind+2],
                            gw_type, flags);
            if (err != 0) {
                fprintf(stderr, "%s: Error during add: %d",
                        argv[0], err);
                return EXIT_FAILURE;
            }

            if (bidirectional_flag == 1) {
                err = ce_gw_add(argv[optind+2], argv[optind+3],
                                gw_type, flags);
                if (err != 0) {
                    fprintf(stderr, "%s: Error during "
                            "add: %d", argv[0], err);
                    return EXIT_FAILURE;
                }
            }

            optind += 4;

            /* add dev [NAME] */
        } else if (!strcmp(argv[optind], "add") &&
                   !strcmp(argv[optind+1], "dev") && optind+2 <= argc) {

            if (optind+3 <= argc) {
                err = ce_gw_add(argv[optind+2], NULL, gw_type,
                                flags);
                if (err != 0) {
                    fprintf(stderr, "%s: Error during "
                            "add: %d", argv[0], err);
                    return EXIT_FAILURE;
                }

                optind += 3;
            } else {

                err = ce_gw_add("cegw%d", NULL, gw_type, flags);
                if (err != 0) {
                    fprintf(stderr, "%s: Error during "
                            "add: %d", argv[0], err);
                    return EXIT_FAILURE;
                }

                optind += 2;
            }

            /* del route ID */
        } else if(!strcmp(argv[optind], "del") &&
                  !strcmp(argv[optind+1], "route") && optind+3 <= argc ) {

            uintmax_t num = strtoumax(argv[optind+2], NULL, 0);
            if (num == UINTMAX_MAX && errno == ERANGE) {
                fprintf(stderr, "%s: Error: Parameter "
                        "ID is not a number %d\n",
                        argv[0], errno);
            }

            err = ce_gw_del((uint32_t) num, NULL);
            if (err != 0) {
                fprintf(stderr, "%s: Error during del: %d\n",
                        argv[0], err);
                return EXIT_FAILURE;
            }

            optind += 3;

            /* del dev DEV_NAME */
        } else if(!strcmp(argv[optind], "del") &&
                  !strcmp(argv[optind+1], "dev") && optind+3 <= argc ) {

            err = ce_gw_del(0, argv[optind+2]);
            if (err != 0) {
                fprintf(stderr, "%s: Error during del: %d\n",
                        argv[0], err);
                return EXIT_FAILURE;
            }

            optind += 3;

            /* echo MSG */
        } else if(!strcmp(argv[optind], "echo") && optind+2 <= argc) {

            err = ce_gw_echo(argv[optind+1]);
            if (err != 0) {
                fprintf(stderr, "%s: Error during echo: %d",
                        argv[0], err);
                return EXIT_FAILURE;
            }

            optind += 2;

            /* route */
        } else if(!strcmp(argv[optind], "route") && optind+1 <= argc) {

            if (optind+2 <= argc) {
                uintmax_t num = strtoumax(argv[optind+1],
                                          NULL, 0);
                if (num == UINTMAX_MAX && errno == ERANGE) {
                    fprintf(stderr, "%s: Error: Parameter "
                            "ID is not a number %d\n",
                            argv[0], errno);
                }

                err = ce_gw_list(num);
                optind += 2;

            } else {
                err = ce_gw_list(0);
                optind += 1;
            }

            if (err != 0) {
                fprintf(stderr, "%s: Error during list: %d",
                        argv[0], err);
                return EXIT_FAILURE;
            }


            /* unrecognized command */
        } else {
            optind += 1;

            while(optind < argc) {
                printf(" %s", argv[optind]);
                optind += 1;
            }

            printf("'\n");
            return EXIT_FAILURE;
        }
    }

    nl_sk_fam_exit();
    return EXIT_SUCCESS;
}

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int nl_cb_echo_answer	(	struct nl_msg *	msg,
		void *	arg
	)

Callback witch receive the message sen bach by kernel.

Parameters

msg	Netlink Message arg a file

Return values

NL_OK

See Also

defined as callback in ce_gw_echo()

Definition at line 448 of file netlink.c.

Referenced by ce_gw_echo().

{
    struct nlmsghdr *msghdr = nlmsg_hdr(msg);
    struct genlmsghdr *gemsghdr =  nlmsg_data(msghdr);

    struct nlattr *a_msg = genlmsg_attrdata(gemsghdr, 0);
    char * a_msg_data = (char *) nla_data(a_msg);
    printf("kernel says: %s\n", a_msg_data);

    return NL_OK;
}

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int nl_cb_general_errno	(	struct sockaddr_nl *	nla,
		struct nlmsgerr *	nlerr,
		void *	arg
	)

A callback wich prints the errno to stderr.

Parameters

nla	Socket address informations
nlerr	error Message arg a file

A callback wich prints the errno to stderr. In nl_sk_fam_init() it is delcared as standart error callback.

Return values

NL_STOP

Definition at line 203 of file netlink.c.

Referenced by ce_gw_list(), and nl_sk_fam_init().

{
    int err = nlerr->error;
    fprintf(stderr, "NETLINK returned Error: %s\n", strerror(err));

    return NL_STOP;
}

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int nl_cb_list_entry	(	struct nl_msg *	msg,
		void *	arg
	)

will be called for every multipart message and prints informations to stdout.

Parameters

msg	Netlink Message arg a file

Return values

NL_OK

See Also

defined as callback in ce_gw_list()

Definition at line 335 of file netlink.c.

References CE_GW_A_DROP, CE_GW_A_DST, CE_GW_A_FLAGS, CE_GW_A_HNDL, CE_GW_A_ID, CE_GW_A_MAX, CE_GW_A_SRC, CE_GW_A_TYPE, ce_gw_genl_policy, enum2str(), flags2str(), flags_array, type_array, TYPE_MAX, and USER_HDR_SIZE.

Referenced by ce_gw_list().

{
    int err;

    struct nlmsghdr *msghdr = nlmsg_hdr(msg);

    struct nlattr *attrs[CE_GW_A_MAX+1];
    err = genlmsg_parse(msghdr, USER_HDR_SIZE, attrs,
                        CE_GW_A_MAX, ce_gw_genl_policy);
    if (err < 0)
        fprintf(stderr, "ERROR Kernel Message Parsing Failed\n");

    char *a_msg_src_data = (char *)nla_data(attrs[CE_GW_A_SRC]);
    char *a_msg_dst_data = (char *)nla_data(attrs[CE_GW_A_DST]);
    uint32_t *a_msg_id_data = (uint32_t *)nla_data(attrs[CE_GW_A_ID]);
    uint32_t *a_msg_flags_data = (uint32_t *)nla_data(attrs[CE_GW_A_FLAGS]);
    uint8_t *a_msg_type_data = (uint8_t *)nla_data(attrs[CE_GW_A_TYPE]);
    uint32_t *a_msg_hndl_data = (uint32_t *)nla_data(attrs[CE_GW_A_HNDL]);
    uint32_t *a_msg_drop_data = (uint32_t *)nla_data(attrs[CE_GW_A_DROP]);

    char *type_str;
    type_str = enum2str(*a_msg_type_data, type_array, 6, TYPE_MAX);
    char *flags_str;
    /* 256 should be big enough */
    flags_str = flags2str(*a_msg_flags_data, flags_array, 256);

    printf(" %-8d %-6s %-6s %-6s %-8d %-8d %s\n", *a_msg_id_data,
           a_msg_src_data, a_msg_dst_data, type_str, *a_msg_hndl_data,
           *a_msg_drop_data, flags_str);

    free(type_str);
    free(flags_str);
    return NL_OK;
}

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int nl_cb_list_finish	(	struct nl_msg *	msg,
		void *	arg
	)

will be called at the end of a multipart message.

Parameters

msg	Netlink Message arg a file

Return values

NL_STOP

See Also

defined as callback in ce_gw_list()

Definition at line 379 of file netlink.c.

Referenced by ce_gw_list().

{
    return NL_STOP;
}

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Variable Documentation

int bidirectional_flag = 0

Definition at line 44 of file main.c.

Referenced by main().

uint32_t flags = 0

Definition at line 45 of file main.c.

uint8_t gw_type = TYPE_NET

Definition at line 46 of file main.c.

int verbose_flag

Definition at line 43 of file main.c.

Referenced by main().