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/Makefile b/contrib/iprange/Makefile
new file mode 100644 (file)
index 0000000..b3c72ed
--- /dev/null
+++ b/contrib/iprange/Makefile
@@ -0,0 +1,13 @@
+CC       = gcc
+OPTIMIZE = -O3
+LDFLAGS  = -s
+
+OBJS     = iprange
+
+all: $(OBJS)
+
+%: %.c
+       $(CC) $(LDFLAGS) $(OPTIMIZE) -o $@ $^
+
+clean:
+       rm -f $(OBJS) *.o *.a *~

diff --git a/contrib/iprange/iprange.c b/contrib/iprange/iprange.c
new file mode 100644 (file)
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);
+       }
+}