diff options
Diffstat (limited to 'admin/iprange/iprange.c')
-rw-r--r-- | admin/iprange/iprange.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/admin/iprange/iprange.c b/admin/iprange/iprange.c new file mode 100644 index 0000000..abae007 --- /dev/null +++ b/admin/iprange/iprange.c @@ -0,0 +1,202 @@ +/* + * network range to IP+mask converter + * + * Copyright 2011-2012 Willy Tarreau <w@1wt.eu> + * + * This program reads lines starting by two IP addresses and outputs them with + * the two IP addresses replaced by a netmask covering the range between these + * IPs (inclusive). When multiple ranges are needed, as many lines are emitted. + * The IP addresses may be delimited by spaces, tabs or commas. Quotes are + * stripped, and lines beginning with a sharp character ('#') are ignored. The + * IP addresses may be either in the dotted format or represented as a 32-bit + * integer value in network byte order. + * + * 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. + */ + +#include <sys/types.h> +#include <sys/socket.h> +#include <arpa/inet.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#define MAXLINE 1024 + +/* returns a string version of an IPv4 address in host order */ +static const char *get_ipv4_addr(unsigned int addr) +{ + struct in_addr a; + + a.s_addr = ntohl(addr); + return inet_ntoa(a); +} + +/* print all networks present between address <low> and address <high> in + * cidr format, followed by <eol>. + */ +static void convert_range(unsigned int low, unsigned int high, const char *eol, const char *pfx) +{ + int bit; + + if (low == high) { + /* single value */ + printf("%s%s%s%s\n", pfx?pfx:"", pfx?" ":"", get_ipv4_addr(low), eol); + return; + } + else if (low > high) { + int swap = low; + low = high; + high = swap; + } + + if (low == high + 1) { + /* full range */ + printf("%s%s0.0.0.0/0%s\n", pfx?pfx:"", pfx?" ":"", eol); + return; + } + //printf("low=%08x high=%08x\n", low, high); + + bit = 0; + while (bit < 32 && low + (1 << bit) - 1 <= high) { + /* enlarge mask */ + if (low & (1 << bit)) { + /* can't aggregate anymore, dump and retry from the same bit */ + printf("%s%s%s/%d%s\n", pfx?pfx:"", pfx?" ":"", get_ipv4_addr(low), 32-bit, eol); + low += (1 << bit); + } + else { + /* try to enlarge the mask as much as possible first */ + bit++; + //printf(" ++bit=%d\n", bit); + } + } + //printf("stopped 1 at low=%08x, bit=%d\n", low, bit); + + bit = 31; + while (bit >= 0 && high - low + 1 != 0) { + /* shrink mask */ + if ((high - low + 1) & (1 << bit)) { + /* large bit accepted, dump and go on from the same bit */ + //printf("max: %08x/%d\n", low, 32-bit); + printf("%s%s%s/%d%s\n", pfx?pfx:"", pfx?" ":"", get_ipv4_addr(low), 32-bit, eol); + low += (1 << bit); + } + else { + bit--; + //printf(" --bit=%d, low=%08x\n", bit, low); + } + } + //printf("stopped at low=%08x\n", low); +} + +static void usage(const char *argv0) +{ + fprintf(stderr, + "Usage: %s [<addr> ...] < iplist.csv\n" + "\n" + "This program reads lines starting by two IP addresses and outputs them with\n" + "the two IP addresses replaced by a netmask covering the range between these\n" + "IPs (inclusive). When multiple ranges are needed, as many lines are emitted.\n" + "The IP addresses may be delimited by spaces, tabs or commas. Quotes are\n" + "stripped, and lines beginning with a sharp character ('#') are ignored. The\n" + "IP addresses may be either in the dotted format or represented as a 32-bit\n" + "integer value in network byte order.\n" + "\n" + "For each optional <addr> specified, only the network it belongs to is returned,\n" + "prefixed with the <addr> value.\n" + "\n", argv0); +} + +int main(int argc, char **argv) +{ + char line[MAXLINE]; + int l, lnum; + char *lb, *le, *hb, *he, *err; + struct in_addr src_addr, dst_addr; + unsigned int sa, da, ta; + + if (argc > 1 && *argv[1] == '-') { + usage(argv[0]); + exit(1); + } + + lnum = 0; + while (fgets(line, sizeof(line), stdin) != NULL) { + l = strlen(line); + if (l && line[l - 1] == '\n') + line[--l] = '\0'; + + lnum++; + /* look for the first field which must be the low address of a range, + * in dotted IPv4 format or as an integer. spaces and commas are + * considered as delimiters, quotes are removed. + */ + for (lb = line; *lb == ' ' || *lb == '\t' || *lb == ',' || *lb == '"'; lb++); + if (!*lb || *lb == '#') + continue; + for (le = lb + 1; *le != ' ' && *le != '\t' && *le != ',' && *le != '"' && *le; le++); + if (!*le) + continue; + /* we have the low address between lb(included) and le(excluded) */ + *(le++) = 0; + + for (hb = le; *hb == ' ' || *hb == '\t' || *hb == ',' || *hb == '"'; hb++); + if (!*hb || *hb == '#') + continue; + for (he = hb + 1; *he != ' ' && *he != '\t' && *he != ',' && *he != '"' && *he; he++); + if (!*he) + continue; + /* we have the high address between hb(included) and he(excluded) */ + *(he++) = 0; + + /* we want to remove a possible ending quote and a possible comma, + * not more. + */ + while (*he == '"') + *(he++) = ' '; + while (*he == ',' || *he == ' ' || *he == '\t') + *(he++) = ' '; + + /* if the trailing string is not empty, prefix it with a space */ + if (*(he-1) == ' ') + he--; + + if (inet_pton(AF_INET, lb, &src_addr) <= 0) { + /* parsing failed, retry with a plain numeric IP */ + src_addr.s_addr = ntohl(strtoul(lb, &err, 10)); + if (err && *err) { + fprintf(stderr, "Failed to parse source address <%s> at line %d, skipping line\n", lb, lnum); + continue; + } + } + + if (inet_pton(AF_INET, hb, &dst_addr) <= 0) { + /* parsing failed, retry with a plain numeric IP */ + dst_addr.s_addr = ntohl(strtoul(hb, &err, 10)); + if (err && *err) { + fprintf(stderr, "Failed to parse destination address <%s> at line %d, skipping line\n", hb, lnum); + continue; + } + } + + sa = htonl(src_addr.s_addr); + da = htonl(dst_addr.s_addr); + if (argc > 1) { + for (l = 1; l < argc; l++) { + if (inet_pton(AF_INET, argv[l], &dst_addr) <= 0) + continue; + ta = htonl(dst_addr.s_addr); + if ((sa <= ta && ta <= da) || (da <= ta && ta <= sa)) + convert_range(sa, da, he, argv[l]); + } + } + else { + convert_range(sa, da, he, NULL); + } + } + exit(0); +} |