MINOR: contrib/iprange: add a network IP range to mask converter
This tool has remained uncommitted in my development tree for almost a year.
Just minor polish and commit.
It can be used to convert some geolocation IP lists to ACLs.
diff --git a/contrib/iprange/iprange.c b/contrib/iprange/iprange.c
new file mode 100644
index 0000000..53d001b
--- /dev/null
+++ b/contrib/iprange/iprange.c
@@ -0,0 +1,187 @@
+/*
+ * 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)
+{
+ int bit;
+
+ if (low == high) {
+ /* single value */
+ printf("%s%s\n", get_ipv4_addr(low), eol);
+ return;
+ }
+ else if (low > high) {
+ int swap = low;
+ low = high;
+ high = swap;
+ }
+
+ if (low == high + 1) {
+ /* full range */
+ printf("0.0.0.0/0%s\n", 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/%d%s\n", 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/%d%s\n", 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 < 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", argv0);
+}
+
+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;
+
+ if (argc > 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);
+ convert_range(sa, da, he);
+ }
+}