GeoIP: support for the MaxMind DB (MMDB) databases

The MaxMind DB format is now recognized, with the fallback to the
legacy format (reached End-of-Life in May 2022).  Migration requires
switching to MMDB database files:

    geoip_country  /usr/share/GeoIP/GeoLite2-Country.mmdb;
    geoip_city     /usr/share/GeoIP/GeoLite2-City.mmdb;
    geoip_org      /usr/share/GeoIP/GeoLite2-ASN.mmdb;

Either libmaxminddb or libGeoIP is sufficient to build the modules;
configure fails if neither is found.

Notes on the MMDB lookups:

*) $geoip_country_code3 and $geoip_city_country_code3 are converted from
   the alpha-2 codes with a compiled-in ISO 3166-1 table, as the MMDB
   databases provide alpha-2 codes only.

*) $geoip_org looks up "autonomous_system_organization", "isp",
   "organization", and "domain" in turn, to match the legacy ASNum, ISP,
   Org, and Domain database editions.

*) $geoip_area_code has no MMDB counterpart and is never found.

*) $geoip_region and $geoip_region_name come from subdivisions[0], and
   thus may differ in value from the legacy ones.

*) $geoip_dma_code comes from location.metro_code, which is deprecated
   by MaxMind and may be absent.

Co-authored-by: Nitin Swami <n.swami@f5.com>

auto/lib/geoip/conf

@@ -3,8 +3,11 @@
 # Copyright (C) Nginx, Inc.
 
 
+GEOIP=NO
+
+
     ngx_feature="GeoIP library"
-    ngx_feature_name=
+    ngx_feature_name=NGX_HAVE_GEOIP
     ngx_feature_run=no
     ngx_feature_incs="#include <GeoIP.h>"
     ngx_feature_path=
@@ -83,6 +86,8 @@ fi
 
 if [ $ngx_found = yes ]; then
 
+    GEOIP=YES
+
     CORE_INCS="$CORE_INCS $ngx_feature_path"
 
     if [ $USE_GEOIP = YES ]; then
@@ -101,11 +106,108 @@ if [ $ngx_found = yes ]; then
     ngx_feature_test="printf(\"%d\", GEOIP_CITY_EDITION_REV0_V6);"
     . auto/feature
 
-else
+fi
+
+
+    ngx_feature="MaxMind DB library"
+    ngx_feature_name=NGX_HAVE_MAXMINDDB
+    ngx_feature_run=no
+    ngx_feature_incs="#include <maxminddb.h>"
+    ngx_feature_path=
+    ngx_feature_libs="-lmaxminddb"
+    ngx_feature_test="MMDB_s mmdb; MMDB_open(NULL, MMDB_MODE_MMAP, &mmdb)"
+    . auto/feature
+
+
+if [ $ngx_found = no ]; then
+
+    # FreeBSD port
+
+    ngx_feature="MaxMind DB library in /usr/local/"
+    ngx_feature_path="/usr/local/include"
+
+    if [ $NGX_RPATH = YES ]; then
+        ngx_feature_libs="-R/usr/local/lib -L/usr/local/lib -lmaxminddb"
+    else
+        ngx_feature_libs="-L/usr/local/lib -lmaxminddb"
+    fi
+
+    . auto/feature
+fi
+
+
+if [ $ngx_found = no ]; then
+
+    # NetBSD port
+
+    ngx_feature="MaxMind DB library in /usr/pkg/"
+    ngx_feature_path="/usr/pkg/include"
+
+    if [ $NGX_RPATH = YES ]; then
+        ngx_feature_libs="-R/usr/pkg/lib -L/usr/pkg/lib -lmaxminddb"
+    else
+        ngx_feature_libs="-L/usr/pkg/lib -lmaxminddb"
+    fi
+
+    . auto/feature
+fi
+
+
+if [ $ngx_found = no ]; then
+
+    # MacPorts
+
+    ngx_feature="MaxMind DB library in /opt/local/"
+    ngx_feature_path="/opt/local/include"
+
+    if [ $NGX_RPATH = YES ]; then
+        ngx_feature_libs="-R/opt/local/lib -L/opt/local/lib -lmaxminddb"
+    else
+        ngx_feature_libs="-L/opt/local/lib -lmaxminddb"
+    fi
+
+    . auto/feature
+fi
+
+
+if [ $ngx_found = no ]; then
+
+    # Homebrew on Apple Silicon
+
+    ngx_feature="MaxMind DB library in /opt/homebrew/"
+    ngx_feature_path="/opt/homebrew/include"
+
+    if [ $NGX_RPATH = YES ]; then
+        ngx_feature_libs="-R/opt/homebrew/lib -L/opt/homebrew/lib -lmaxminddb"
+    else
+        ngx_feature_libs="-L/opt/homebrew/lib -lmaxminddb"
+    fi
+
+    . auto/feature
+fi
+
+
+if [ $ngx_found = yes ]; then
+
+    GEOIP=YES
+
+    CORE_INCS="$CORE_INCS $ngx_feature_path"
+
+    if [ $USE_GEOIP = YES ]; then
+        CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
+    fi
+
+    NGX_LIB_GEOIP="$NGX_LIB_GEOIP $ngx_feature_libs"
+
+fi
+
+
+if [ $GEOIP != YES ]; then
 
 cat << END
 
-$0: error: the GeoIP module requires the GeoIP library.
+$0: error: the GeoIP module requires the MaxMind DB library
+or the legacy GeoIP library.
 You can either do not enable the module or install the library.
 
 END