utils.c

/*
 * src/utils.c          Utilities
 *
 *      This library is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU Lesser General Public
 *      License as published by the Free Software Foundation version 2.1
 *      of the License.
 *
 * Copyright (c) 2003-2009 Thomas Graf <tgraf@suug.ch>
 */

/**
 * @defgroup cli Command Line Interface API
 *
 * @{
 *
 * These modules provide an interface for text based applications. The
 * functions provided are wrappers for their libnl equivalent with
 * added error handling. The functions check for allocation failures,
 * invalid input, and unknown types and will print error messages
 * accordingly via nl_cli_fatal().
 */

#include <netlink/cli/utils.h>

/**
 * Parse a text based 32 bit unsigned integer argument
 * @arg arg             Integer in text form.
 *
 * Tries to convert the number provided in arg to a uint32_t. Will call
 * nl_cli_fatal() if the conversion fails.
 *
 * @return 32bit unsigned integer.
 */
uint32_t nl_cli_parse_u32(const char *arg)
{
        unsigned long lval;
        char *endptr;

        lval = strtoul(arg, &endptr, 0);
        if (endptr == arg || lval == ULONG_MAX)
                nl_cli_fatal(EINVAL, "Unable to parse \"%s\", not a number.",
                             arg);

        return (uint32_t) lval;
}

void nl_cli_print_version(void)
{
        printf("libnl tools version %s\n", LIBNL_VERSION);
        printf(
        "Copyright (C) 2003-2010 Thomas Graf <tgraf@redhat.com>\n"
        "\n"
        "This program comes with ABSOLUTELY NO WARRANTY. This is free \n"
        "software, and you are welcome to redistribute it under certain\n"
        "conditions. See the GNU General Public License for details.\n"
        );

        exit(0);
}

/**
 * Print error message and quit application
 * @arg err             Error code.
 * @arg fmt             Error message.
 *
 * Prints the formatted error message to stderr and quits the application
 * using the provided error code.
 */
void nl_cli_fatal(int err, const char *fmt, ...)
{
        va_list ap;
        char buf[256];

        fprintf(stderr, "Error: ");

        if (fmt) {
                va_start(ap, fmt);
                vfprintf(stderr, fmt, ap);
                va_end(ap);
                fprintf(stderr, "\n");
        } else
                fprintf(stderr, "%s\n", strerror_r(err, buf, sizeof(buf)));

        exit(abs(err));
}

int nl_cli_connect(struct nl_sock *sk, int protocol)
{
        int err;

        if ((err = nl_connect(sk, protocol)) < 0)
                nl_cli_fatal(err, "Unable to connect netlink socket: %s",
                             nl_geterror(err));

        return err;
}

struct nl_sock *nl_cli_alloc_socket(void)
{
        struct nl_sock *sock;

        if (!(sock = nl_socket_alloc()))
                nl_cli_fatal(ENOBUFS, "Unable to allocate netlink socket");

        return sock;
}

struct nl_addr *nl_cli_addr_parse(const char *str, int family)
{
        struct nl_addr *addr;
        int err;

        if ((err = nl_addr_parse(str, family, &addr)) < 0)
                nl_cli_fatal(err, "Unable to parse address \"%s\": %s",
                             str, nl_geterror(err));

        return addr;
}

int nl_cli_parse_dumptype(const char *str)
{
        if (!strcasecmp(str, "brief"))
                return NL_DUMP_LINE;
        else if (!strcasecmp(str, "details") || !strcasecmp(str, "detailed"))
                return NL_DUMP_DETAILS;
        else if (!strcasecmp(str, "stats"))
                return NL_DUMP_STATS;
        else
                nl_cli_fatal(EINVAL, "Invalid dump type \"%s\".\n", str);

        return 0;
}

int nl_cli_confirm(struct nl_object *obj, struct nl_dump_params *params,
                   int default_yes)
{
        nl_object_dump(obj, params);

        for (;;) {
                char buf[32] = { 0 };
                int answer;

                printf("Delete? (%c/%c) ",
                        default_yes ? 'Y' : 'y',
                        default_yes ? 'n' : 'N');

                if (!fgets(buf, sizeof(buf), stdin)) {
                        fprintf(stderr, "Error while reading\n.");
                        continue;
                }

                switch ((answer = tolower(buf[0]))) {
                case '\n':
                        answer = default_yes ? 'y' : 'n';
                case 'y':
                case 'n':
                        return answer == 'y';
                }

                fprintf(stderr, "Invalid input, try again.\n");
        }

        return 0;

}

struct nl_cache *nl_cli_alloc_cache(struct nl_sock *sock, const char *name,
                            int (*ac)(struct nl_sock *, struct nl_cache **))
{
        struct nl_cache *cache;
        int err;

        if ((err = ac(sock, &cache)) < 0)
                nl_cli_fatal(err, "Unable to allocate %s cache: %s",
                             name, nl_geterror(err));

        nl_cache_mngt_provide(cache);

        return cache;
}

void nl_cli_load_module(const char *prefix, const char *name)
{
        char path[FILENAME_MAX+1];
        void *handle;

        snprintf(path, sizeof(path), "%s/%s/%s.so",
                 PKGLIBDIR, prefix, name);

        if (!(handle = dlopen(path, RTLD_NOW)))
                nl_cli_fatal(ENOENT, "Unable to load module \"%s\": %s\n",
                        path, dlerror());
}

/** @} */