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      1 /*
      2  * src/utils.c		Utilities
      3  *
      4  *	This library is free software; you can redistribute it and/or
      5  *	modify it under the terms of the GNU Lesser General Public
      6  *	License as published by the Free Software Foundation version 2.1
      7  *	of the License.
      8  *
      9  * Copyright (c) 2003-2009 Thomas Graf <tgraf (at) suug.ch>
     10  */
     11 
     12 /**
     13  * @defgroup cli Command Line Interface API
     14  *
     15  * @{
     16  *
     17  * These modules provide an interface for text based applications. The
     18  * functions provided are wrappers for their libnl equivalent with
     19  * added error handling. The functions check for allocation failures,
     20  * invalid input, and unknown types and will print error messages
     21  * accordingly via nl_cli_fatal().
     22  */
     23 
     24 #include <netlink/cli/utils.h>
     25 
     26 /**
     27  * Parse a text based 32 bit unsigned integer argument
     28  * @arg arg		Integer in text form.
     29  *
     30  * Tries to convert the number provided in arg to a uint32_t. Will call
     31  * nl_cli_fatal() if the conversion fails.
     32  *
     33  * @return 32bit unsigned integer.
     34  */
     35 uint32_t nl_cli_parse_u32(const char *arg)
     36 {
     37 	unsigned long lval;
     38 	char *endptr;
     39 
     40 	lval = strtoul(arg, &endptr, 0);
     41 	if (endptr == arg || lval == ULONG_MAX)
     42 		nl_cli_fatal(EINVAL, "Unable to parse \"%s\", not a number.",
     43 			     arg);
     44 
     45 	return (uint32_t) lval;
     46 }
     47 
     48 void nl_cli_print_version(void)
     49 {
     50 	printf("libnl tools version %s\n", LIBNL_VERSION);
     51 	printf(
     52 	"Copyright (C) 2003-2010 Thomas Graf <tgraf (at) redhat.com>\n"
     53 	"\n"
     54 	"This program comes with ABSOLUTELY NO WARRANTY. This is free \n"
     55 	"software, and you are welcome to redistribute it under certain\n"
     56 	"conditions. See the GNU General Public License for details.\n"
     57 	);
     58 
     59 	exit(0);
     60 }
     61 
     62 /**
     63  * Print error message and quit application
     64  * @arg err		Error code.
     65  * @arg fmt		Error message.
     66  *
     67  * Prints the formatted error message to stderr and quits the application
     68  * using the provided error code.
     69  */
     70 void nl_cli_fatal(int err, const char *fmt, ...)
     71 {
     72 	va_list ap;
     73 	char buf[256];
     74 
     75 	fprintf(stderr, "Error: ");
     76 
     77 	if (fmt) {
     78 		va_start(ap, fmt);
     79 		vfprintf(stderr, fmt, ap);
     80 		va_end(ap);
     81 		fprintf(stderr, "\n");
     82 	} else
     83 		fprintf(stderr, "%s\n", strerror_r(err, buf, sizeof(buf)));
     84 
     85 	exit(abs(err));
     86 }
     87 
     88 int nl_cli_connect(struct nl_sock *sk, int protocol)
     89 {
     90 	int err;
     91 
     92 	if ((err = nl_connect(sk, protocol)) < 0)
     93 		nl_cli_fatal(err, "Unable to connect netlink socket: %s",
     94 			     nl_geterror(err));
     95 
     96 	return err;
     97 }
     98 
     99 struct nl_sock *nl_cli_alloc_socket(void)
    100 {
    101 	struct nl_sock *sock;
    102 
    103 	if (!(sock = nl_socket_alloc()))
    104 		nl_cli_fatal(ENOBUFS, "Unable to allocate netlink socket");
    105 
    106 	return sock;
    107 }
    108 
    109 struct nl_addr *nl_cli_addr_parse(const char *str, int family)
    110 {
    111 	struct nl_addr *addr;
    112 	int err;
    113 
    114 	if ((err = nl_addr_parse(str, family, &addr)) < 0)
    115 		nl_cli_fatal(err, "Unable to parse address \"%s\": %s",
    116 			     str, nl_geterror(err));
    117 
    118 	return addr;
    119 }
    120 
    121 int nl_cli_parse_dumptype(const char *str)
    122 {
    123 	if (!strcasecmp(str, "brief"))
    124 		return NL_DUMP_LINE;
    125 	else if (!strcasecmp(str, "details") || !strcasecmp(str, "detailed"))
    126 		return NL_DUMP_DETAILS;
    127 	else if (!strcasecmp(str, "stats"))
    128 		return NL_DUMP_STATS;
    129 	else
    130 		nl_cli_fatal(EINVAL, "Invalid dump type \"%s\".\n", str);
    131 
    132 	return 0;
    133 }
    134 
    135 int nl_cli_confirm(struct nl_object *obj, struct nl_dump_params *params,
    136 		   int default_yes)
    137 {
    138 	nl_object_dump(obj, params);
    139 
    140 	for (;;) {
    141 		char buf[32] = { 0 };
    142 		int answer;
    143 
    144 		printf("Delete? (%c/%c) ",
    145 			default_yes ? 'Y' : 'y',
    146 			default_yes ? 'n' : 'N');
    147 
    148 		if (!fgets(buf, sizeof(buf), stdin)) {
    149 			fprintf(stderr, "Error while reading\n.");
    150 			continue;
    151 		}
    152 
    153 		switch ((answer = tolower(buf[0]))) {
    154 		case '\n':
    155 			answer = default_yes ? 'y' : 'n';
    156 		case 'y':
    157 		case 'n':
    158 			return answer == 'y';
    159 		}
    160 
    161 		fprintf(stderr, "Invalid input, try again.\n");
    162 	}
    163 
    164 	return 0;
    165 
    166 }
    167 
    168 struct nl_cache *nl_cli_alloc_cache(struct nl_sock *sock, const char *name,
    169 			    int (*ac)(struct nl_sock *, struct nl_cache **))
    170 {
    171 	struct nl_cache *cache;
    172 	int err;
    173 
    174 	if ((err = ac(sock, &cache)) < 0)
    175 		nl_cli_fatal(err, "Unable to allocate %s cache: %s",
    176 			     name, nl_geterror(err));
    177 
    178 	nl_cache_mngt_provide(cache);
    179 
    180 	return cache;
    181 }
    182 
    183 void nl_cli_load_module(const char *prefix, const char *name)
    184 {
    185 	char path[FILENAME_MAX+1];
    186 	void *handle;
    187 
    188 	snprintf(path, sizeof(path), "%s/%s/%s.so",
    189 		 PKGLIBDIR, prefix, name);
    190 
    191 	if (!(handle = dlopen(path, RTLD_NOW)))
    192 		nl_cli_fatal(ENOENT, "Unable to load module \"%s\": %s\n",
    193 			path, dlerror());
    194 }
    195 
    196 /** @} */
    197