diff options
Diffstat (limited to 'package/6rd/src')
| -rw-r--r-- | package/6rd/src/6rdcalc.c | 126 | ||||
| -rw-r--r-- | package/6rd/src/Makefile | 7 |
2 files changed, 133 insertions, 0 deletions
diff --git a/package/6rd/src/6rdcalc.c b/package/6rd/src/6rdcalc.c new file mode 100644 index 000000000..56e07d255 --- /dev/null +++ b/package/6rd/src/6rdcalc.c @@ -0,0 +1,126 @@ +/* + * Utility used to calculate the 6rd subnet. + * + * Copyright 2012, Stéphan Kochen <stephan@kochen.nl> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/errno.h> +#include <arpa/inet.h> +#include <netinet/in.h> + +#define INET_PREFIXSTRLEN (INET_ADDRSTRLEN+3) +#define INET6_PREFIXSTRLEN (INET6_ADDRSTRLEN+4) + +static void print_usage() +{ + fprintf(stderr, "Usage: 6rdcalc <v6 prefix>/<mask> <v4 address>/<mask>\n"); + exit(1); +} + +static void print_error() +{ + fprintf(stderr, "%s", strerror(errno)); + exit(1); +} + +static void parse_str(int af, char *str, void *addr, unsigned long *mask) +{ + int ret; + char *slash; + + /* Split the address at the slash. */ + if ((slash = strchr(str, '/')) == NULL) + print_usage(); + *slash = '\0'; + + /* Parse the address. */ + if ((ret = inet_pton(af, str, addr)) != 1) { + if (ret == 0) + print_usage(); + else + print_error(); + } + + /* Parse the mask. */ + *mask = strtoul(slash+1, NULL, 10); + if ((af == AF_INET && *mask > 32) || + (af == AF_INET6 && *mask > 128)) + print_usage(); +} + +int main(int argc, const char **argv) +{ + char v6str[INET6_PREFIXSTRLEN], v4str[INET_PREFIXSTRLEN]; + struct in6_addr v6; + struct in_addr v4; + unsigned long v6it, v4it, mask; + unsigned char *byte4, *byte6; + unsigned char bit4, bit6; + + /* Check parameters. */ + if (argc != 3) + print_usage(); + + /* Parse the v6 address. */ + strncpy(v6str, argv[1], INET6_PREFIXSTRLEN); + v6str[INET6_PREFIXSTRLEN-1] = '\0'; + parse_str(AF_INET6, v6str, &v6, &v6it); + + /* Parse the v4 address */ + strncpy(v4str, argv[2], INET_PREFIXSTRLEN); + v6str[INET_PREFIXSTRLEN-1] = '\0'; + parse_str(AF_INET, v4str, &v4, &v4it); + + /* Check if the combined mask is within bounds. */ + mask = (32 - v4it) + v6it; + if (mask > 128) + print_usage(); + + /* Combine the addresses. */ + while (v4it < 32) { + byte6 = (unsigned char *)(&v6.s6_addr) + (v6it >> 3); + byte4 = (unsigned char *)(&v4.s_addr) + (v4it >> 3); + bit6 = 128 >> (v6it & 0x07); + bit4 = 128 >> (v4it & 0x07); + + if (*byte4 & bit4) + *byte6 |= bit6; + else + *byte6 &= ~bit6; + + v4it++; v6it++; + } + + /* Clear remaining bits. */ + while (v6it < 128) { + byte6 = (unsigned char *)(&v6.s6_addr) + (v6it >> 2); + bit6 = 128 >> (v6it & 0x07); + + *byte6 &= ~bit6; + + v6it++; + } + + /* Print the subnet prefix. */ + if (inet_ntop(AF_INET6, &v6, v6str, sizeof(v6str)) == NULL) + print_error(); + printf("%s/%lu\n", v6str, mask); + return 0; +} diff --git a/package/6rd/src/Makefile b/package/6rd/src/Makefile new file mode 100644 index 000000000..2881d4358 --- /dev/null +++ b/package/6rd/src/Makefile @@ -0,0 +1,7 @@ +all: 6rdcalc + +6rdcalc: 6rdcalc.c + $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $< + +clean: + rm -f 6rdcalc |