utils.c

00001 /*
00002  * src/utils.c          Utilities
00003  *
00004  *      This library is free software; you can redistribute it and/or
00005  *      modify it under the terms of the GNU Lesser General Public
00006  *      License as published by the Free Software Foundation version 2.1
00007  *      of the License.
00008  *
00009  * Copyright (c) 2003-2009 Thomas Graf <tgraf@suug.ch>
00010  */
00011 
00012 /**
00013  * @defgroup cli Command Line Interface API
00014  *
00015  * @{
00016  *
00017  * These modules provide an interface for text based applications. The
00018  * functions provided are wrappers for their libnl equivalent with
00019  * added error handling. The functions check for allocation failures,
00020  * invalid input, and unknown types and will print error messages
00021  * accordingly via nl_cli_fatal().
00022  */
00023 
00024 #include <netlink/cli/utils.h>
00025 
00026 /**
00027  * Parse a text based 32 bit unsigned integer argument
00028  * @arg arg             Integer in text form.
00029  *
00030  * Tries to convert the number provided in arg to a uint32_t. Will call
00031  * nl_cli_fatal() if the conversion fails.
00032  *
00033  * @return 32bit unsigned integer.
00034  */
00035 uint32_t nl_cli_parse_u32(const char *arg)
00036 {
00037         unsigned long lval;
00038         char *endptr;
00039 
00040         lval = strtoul(arg, &endptr, 0);
00041         if (endptr == arg || lval == ULONG_MAX)
00042                 nl_cli_fatal(EINVAL, "Unable to parse \"%s\", not a number.",
00043                              arg);
00044 
00045         return (uint32_t) lval;
00046 }
00047 
00048 void nl_cli_print_version(void)
00049 {
00050         printf("libnl tools version %s\n", LIBNL_VERSION);
00051         printf(
00052         "Copyright (C) 2003-2010 Thomas Graf <tgraf@redhat.com>\n"
00053         "\n"
00054         "This program comes with ABSOLUTELY NO WARRANTY. This is free \n"
00055         "software, and you are welcome to redistribute it under certain\n"
00056         "conditions. See the GNU General Public License for details.\n"
00057         );
00058 
00059         exit(0);
00060 }
00061 
00062 /**
00063  * Print error message and quit application
00064  * @arg err             Error code.
00065  * @arg fmt             Error message.
00066  *
00067  * Prints the formatted error message to stderr and quits the application
00068  * using the provided error code.
00069  */
00070 void nl_cli_fatal(int err, const char *fmt, ...)
00071 {
00072         va_list ap;
00073 
00074         fprintf(stderr, "Error: ");
00075 
00076         if (fmt) {
00077                 va_start(ap, fmt);
00078                 vfprintf(stderr, fmt, ap);
00079                 va_end(ap);
00080                 fprintf(stderr, "\n");
00081         } else
00082                 fprintf(stderr, "%s\n", strerror(err));
00083 
00084         exit(abs(err));
00085 }
00086 
00087 int nl_cli_connect(struct nl_sock *sk, int protocol)
00088 {
00089         int err;
00090 
00091         if ((err = nl_connect(sk, protocol)) < 0)
00092                 nl_cli_fatal(err, "Unable to connect netlink socket: %s",
00093                              nl_geterror(err));
00094 
00095         return err;
00096 }
00097 
00098 struct nl_sock *nl_cli_alloc_socket(void)
00099 {
00100         struct nl_sock *sock;
00101 
00102         if (!(sock = nl_socket_alloc()))
00103                 nl_cli_fatal(ENOBUFS, "Unable to allocate netlink socket");
00104 
00105         return sock;
00106 }
00107 
00108 struct nl_addr *nl_cli_addr_parse(const char *str, int family)
00109 {
00110         struct nl_addr *addr;
00111         int err;
00112 
00113         if ((err = nl_addr_parse(str, family, &addr)) < 0)
00114                 nl_cli_fatal(err, "Unable to parse address \"%s\": %s",
00115                              str, nl_geterror(err));
00116 
00117         return addr;
00118 }
00119 
00120 int nl_cli_parse_dumptype(const char *str)
00121 {
00122         if (!strcasecmp(str, "brief"))
00123                 return NL_DUMP_LINE;
00124         else if (!strcasecmp(str, "details") || !strcasecmp(str, "detailed"))
00125                 return NL_DUMP_DETAILS;
00126         else if (!strcasecmp(str, "stats"))
00127                 return NL_DUMP_STATS;
00128         else
00129                 nl_cli_fatal(EINVAL, "Invalid dump type \"%s\".\n", str);
00130 
00131         return 0;
00132 }
00133 
00134 int nl_cli_confirm(struct nl_object *obj, struct nl_dump_params *params,
00135                    int default_yes)
00136 {
00137         nl_object_dump(obj, params);
00138 
00139         for (;;) {
00140                 char buf[32] = { 0 };
00141                 int answer;
00142 
00143                 printf("Delete? (%c/%c) ",
00144                         default_yes ? 'Y' : 'y',
00145                         default_yes ? 'n' : 'N');
00146 
00147                 if (!fgets(buf, sizeof(buf), stdin)) {
00148                         fprintf(stderr, "Error while reading\n.");
00149                         continue;
00150                 }
00151 
00152                 switch ((answer = tolower(buf[0]))) {
00153                 case '\n':
00154                         answer = default_yes ? 'y' : 'n';
00155                 case 'y':
00156                 case 'n':
00157                         return answer == 'y';
00158                 }
00159 
00160                 fprintf(stderr, "Invalid input, try again.\n");
00161         }
00162 
00163         return 0;
00164 
00165 }
00166 
00167 struct nl_cache *nl_cli_alloc_cache(struct nl_sock *sock, const char *name,
00168                             int (*ac)(struct nl_sock *, struct nl_cache **))
00169 {
00170         struct nl_cache *cache;
00171         int err;
00172 
00173         if ((err = ac(sock, &cache)) < 0)
00174                 nl_cli_fatal(err, "Unable to allocate %s cache: %s",
00175                              name, nl_geterror(err));
00176 
00177         nl_cache_mngt_provide(cache);
00178 
00179         return cache;
00180 }
00181 
00182 void nl_cli_load_module(const char *prefix, const char *name)
00183 {
00184         char path[FILENAME_MAX+1];
00185         void *handle;
00186 
00187         snprintf(path, sizeof(path), "%s/%s/%s.so",
00188                  PKGLIBDIR, prefix, name);
00189 
00190         if (!(handle = dlopen(path, RTLD_NOW)))
00191                 nl_cli_fatal(ENOENT, "Unable to load module \"%s\": %s\n",
00192                         path, dlerror());
00193 }
00194 
00195 /** @} */