utils.c

/* SPDX-License-Identifier: LGPL-2.1-only */
/*
 * 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>
#include <locale.h>
 
#include "lib/defs.h"
 
#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#endif
 
/**
 * 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;
 
        fprintf(stderr, "Error: ");
 
        if (fmt) {
                va_start(ap, fmt);
                vfprintf(stderr, fmt, ap);
                va_end(ap);
                fprintf(stderr, "\n");
        } else {
                char *buf;
#ifdef HAVE_STRERROR_L
                locale_t loc = newlocale(LC_MESSAGES_MASK, "", (locale_t)0);
                if (loc == (locale_t)0) {
                        if (errno == ENOENT)
                                loc = newlocale(LC_MESSAGES_MASK,
                                                "POSIX", (locale_t)0);
                        if (loc == (locale_t)0)
                                buf = "newlocale() failed";
                }
                if (loc != (locale_t)0)
                        buf = strerror_l(err, loc);
#else
                buf = strerror(err);
#endif
                fprintf(stderr, "%s\n", buf);
#ifdef HAVE_STRERROR_L
                if (loc != (locale_t)0)
                        freelocale(loc);
#endif
        }
 
        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';
                        /* fall through */
                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;
}
 
struct nl_cache *nl_cli_alloc_cache_flags(struct nl_sock *sock,
                            const char *name, unsigned int flags,
                            int (*ac)(struct nl_sock *, struct nl_cache **,
                                      unsigned int))
{
        struct nl_cache *cache;
        int err;
 
        if ((err = ac(sock, &cache, flags)) < 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];
 
        snprintf(path, sizeof(path), "%s/%s/%s.so",
                 PKGLIBDIR, prefix, name);
 
#ifdef HAVE_DLFCN_H
        {
                void *handle;
 
                handle = dlopen(path, RTLD_NOW);
                if (!handle) {
                        nl_cli_fatal(ENOENT, "Unable to load module \"%s\": %s\n",
                                     path, dlerror());
                }
                /* We intentionally leak the dlopen handle. */
                /* coverity[RESOURCE_LEAK] */
        }
#else
        nl_cli_fatal(ENOTSUP, "Unable to load module \"%s\": built without dynamic libraries support\n",
                     path);
#endif
}
 
/** @} */