DeforaNetworks/fwknop
DeforaNetworks/fwknop
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Resolve ip address in all of tha nat modes (mrash/fwknop#43).

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This commit is contained in:
Franck Joncourt 2013-04-10 16:06:06 +02:00
parent 8f3e6a4ed1
commit fd767a1f47
2 changed files with 133 additions and 23 deletions
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155
client/fwknop.c
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@ -59,14 +59,117 @@ static void clean_exit(fko_ctx_t ctx, fko_cli_options_t *opts,
unsigned int exit_status);
static void *get_in_addr(struct sockaddr *sa);
static int resolve_dest_adr(const char *dns_str, struct addrinfo *hints, char *ip_str, size_t ip_bufsize);
static int is_hostname_str_with_port(const char *str, char *hostname, size_t hostname_bufsize, int *port);
#define MAX_CMDLINE_ARGS 50 /* should be way more than enough */
#define MAX_CMDLINE_ARGS 50 /*!< should be way more than enough */
#define IPV4_STR_TEMPLATE "%u.%u.%u.%u" /*!< Template for a string as an ipv4 address with sscanf */
#define NAT_ACCESS_STR_TEMPLATE "%s,%d" /*!< Template for a nat access string ip,port with sscanf*/
#define HOSTNAME_BUFSIZE 64 /*!< Maximum size of a hostname string */
/**
* @brief Check whether a string is an ipv4 address or not
*
* @param str String to check for an ipv4 address.
*
* @return 1 if the string is an ipv4 address, 0 otherwise.
*/
static int
is_ipv4_str(char *str)
{
int o1, o2, o3, o4;
int valid_ipv4;
/* Check format and values.
*/
if((sscanf(str, IPV4_STR_TEMPLATE, &o1, &o2, &o3, &o4)) == 4
&& o1 >= 0 && o1 <= 255
&& o2 >= 0 && o2 <= 255
&& o3 >= 0 && o3 <= 255
&& o4 >= 0 && o4 <= 255)
{
valid_ipv4 = 1;
}
else
valid_ipv4 = 0;
return valid_ipv4;
}
/**
* @brief Check whether a string is an ipv6 address or not
*
* @param str String to check for an ipv6 address.
*
* @return 1 if the string is an ipv6 address, 0 otherwise.
*/
static int
is_ipv6_str(char *str)
{
return 0;
}
/**
* @brief Check a string to find out if it is built as 'hostname,port'
*
* This function check if we can extract an hostname and a port from the string.
* If yes, we return 1, and both the hostname buffer and the port number are set
* accordingly.
*
* We could have used sscanf() here with a template "%[^,],%u", but this way we
* do not limit the size of the value copy in the hostname destination buffer.
* Limiting the string in the sscanf() can be done but would prevent any easy change
* for the hostname buffer size.
*
* @param str String to parse.
* @param hostname Buffer where to store the hostname value read from @str.
* @param hostname_bufsize Hostname buffer size.
* @param port Value of the port read from @str.
*
* @return 1 if the string is built as 'hostname,port', 0 otherwise.
*/
static int
is_hostname_str_with_port(const char *str, char *hostname, size_t hostname_bufsize, int *port)
{
int valid = 0; /* Result of the function */
char buf[MAX_LINE_LEN]; /* Copy of the buffer eg. "hostname,port" */
char *h; /* Pointer on the hostname string */
char *p; /* Ponter on the port string */
memset(buf, 0, sizeof(buf));
memset(hostname, 0, hostname_bufsize);
*port = 0;
/* Replace the comma in the string with a NULL char to split the
* buffer in two strings (hostname and port) */
strlcpy(buf, str, sizeof(buf));
p = strchr(buf, ',');
if(p != NULL)
{
*p++ = 0;
h = buf;
*port = atoi(p);
/* If the string does not match an ipv4 or ipv6 address we assume this
* is an hostname. We make sure the port is in the good range too */
if ( (is_ipv4_str(buf) == 0)
&& (is_ipv6_str(buf) == 0)
&& ((*port > 0) && (*port < 65536)) )
{
strlcpy(hostname, h, hostname_bufsize);
valid = 1;
}
}
return valid;
}
/**
* @brief Grab the sin address from the sockaddr structure.
*
* This functions returns the sin address as a sockaddr_in or sockaddr_in6
* This function returns the sin address as a sockaddr_in or sockaddr_in6
* structure according to the family set (ipv4 or ipv6) in the sockaddr
* structure.
*
@ -74,7 +177,8 @@ static int resolve_dest_adr(const char *dns_str, struct addrinfo *hints, char *i
*
* @return the sin addr if the sa family is AF_INET or the sin6_addr otherwise.
*/
static void *get_in_addr(struct sockaddr *sa)
static void *
get_in_addr(struct sockaddr *sa)
{
if (sa->sa_family == AF_INET)
{
@ -97,7 +201,8 @@ static void *get_in_addr(struct sockaddr *sa)
*
* @return 0 if successful, 1 if an error occured.
*/
static int resolve_dest_adr(const char *dns_str, struct addrinfo *hints, char *ip_str, size_t ip_bufsize)
static int
resolve_dest_adr(const char *dns_str, struct addrinfo *hints, char *ip_str, size_t ip_bufsize)
{
int error; /* Function error return code */
struct addrinfo *result; /* Result of getaddrinfo() */
@ -747,7 +852,9 @@ set_nat_access(fko_ctx_t ctx, fko_cli_options_t *options, const char * const acc
char nat_access_buf[MAX_LINE_LEN] = {0};
char tmp_access_port[MAX_PORT_STR_LEN+1], *ndx = NULL;
int access_port = 0, i = 0, is_err = 0;
char dst_ip_str[INET_ADDRSTRLEN];
char dst_ip_str[INET_ADDRSTRLEN] = {0};
char hostname[HOSTNAME_BUFSIZE] = {0};
int port = 0;
struct addrinfo hints;
memset(nat_access_buf, 0x0, MAX_LINE_LEN);
@ -781,22 +888,7 @@ set_nat_access(fko_ctx_t ctx, fko_cli_options_t *options, const char * const acc
if (options->nat_local && options->nat_access_str[0] == 0x0)
{
/* Speed up the name resolution by forcing ipv4 (AF_INET).
* A NULL pointer could be used instead if there is no constraint.
* Maybe when ipv6 support will be enable the structure could initialize the
* family to either AF_INET or AF_INET6 */
hints.ai_family = AF_INET;
if (resolve_dest_adr(options->spa_server_str, &hints, dst_ip_str, sizeof(dst_ip_str)) != 0)
{
fprintf(stderr, "[*] Unable to resolve %s as an ip address\n",
options->spa_server_str);
clean_exit(ctx, options, EXIT_FAILURE);
}
strlcpy(options->spa_server_str, dst_ip_str, sizeof(options->spa_server_str));
snprintf(nat_access_buf, MAX_LINE_LEN, "%s,%d",
snprintf(nat_access_buf, MAX_LINE_LEN, NAT_ACCESS_STR_TEMPLATE,
options->spa_server_str, access_port);
}
@ -809,11 +901,30 @@ set_nat_access(fko_ctx_t ctx, fko_cli_options_t *options, const char * const acc
}
else
{
snprintf(nat_access_buf, MAX_LINE_LEN, "%s,%d",
snprintf(nat_access_buf, MAX_LINE_LEN, NAT_ACCESS_STR_TEMPLATE,
options->nat_access_str, access_port);
}
}
if (is_hostname_str_with_port(nat_access_buf, hostname, sizeof(hostname), &port))
{
/* Speed up the name resolution by forcing ipv4 (AF_INET).
* A NULL pointer could be used instead if there is no constraint.
* Maybe when ipv6 support will be enable the structure could initialize the
* family to either AF_INET or AF_INET6 */
hints.ai_family = AF_INET;
if (resolve_dest_adr(hostname, &hints, dst_ip_str, sizeof(dst_ip_str)) != 0)
{
fprintf(stderr, "[*] Unable to resolve %s as an ip address\n",
hostname);
clean_exit(ctx, options, EXIT_FAILURE);
}
snprintf(nat_access_buf, MAX_LINE_LEN, NAT_ACCESS_STR_TEMPLATE,
dst_ip_str, port);
}
if(options->nat_rand_port)
{
/* Must print to stdout what the random port is since

1
test/local_spa.key
View File

@ -1,4 +1,3 @@
127.0.0.1: fwknoptest
localhost: fwknoptest
some.host.through.proxy.com: fwknoptest
74.220.215.85: fwknoptest