install: Readd ALSA detection if needed.

Asterisk 21 removed chan_alsa, and with it
detection of the ALSA library. Other out-of-tree
modules (not in this repo) may still depend on
ALSA, so this allows the build system changes
to be reversed if needed so these modules can
still be built without modification.

This option does NOT patch chan_alsa back in.

patches/alsa.diff

@@ -0,0 +1,44 @@
+diff --git a/build_tools/menuselect-deps.in b/build_tools/menuselect-deps.in
+index 6594a922eb..21a8a2ac49 100644
+--- a/build_tools/menuselect-deps.in
++++ b/build_tools/menuselect-deps.in
+@@ -1,3 +1,4 @@
++ALSA=@PBX_ALSA@
+ BLUETOOTH=@PBX_BLUETOOTH@
+ BEANSTALK=@PBX_BEANSTALK@
+ COROSYNC=@PBX_COROSYNC@
+diff --git a/configure.ac b/configure.ac
+index a3563e97a9..1d6a6143af 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -530,6 +530,7 @@ THIRD_PARTY_CONFIGURE()
+ # by the --with option name (the third field),
+ # to make things easier for the users.
+
++AST_EXT_LIB_SETUP([ALSA], [Advanced Linux Sound Architecture], [asound])
+ AST_EXT_LIB_SETUP([BFD], [Debug symbol decoding], [bfd])
+
+ # BKTR is used for backtrace support on platforms that do not
+@@ -1633,6 +1634,8 @@ fi
+
+ # do the package library checks now
+
++AST_EXT_LIB_CHECK([ALSA], [asound], [snd_pcm_open], [alsa/asoundlib.h])
++
+ AST_EXT_LIB_CHECK([BFD], [bfd], [bfd_openr], [bfd.h])
+ # Fedora/RedHat/CentOS require extra libraries
+ AST_EXT_LIB_CHECK([BFD], [bfd], [bfd_openr], [bfd.h], [-ldl -liberty])
+diff --git a/makeopts.in b/makeopts.in
+index f7824f3476..bddf77ac1a 100644
+--- a/makeopts.in
++++ b/makeopts.in
+@@ -130,6 +130,9 @@ C_COMPILER_FAMILY=@AST_C_COMPILER_FAMILY@
+ AST_RPATH=@AST_RPATH@
+ AST_FORTIFY_SOURCE=@AST_FORTIFY_SOURCE@
+
++ALSA_INCLUDE=@ALSA_INCLUDE@
++ALSA_LIB=@ALSA_LIB@
++
+ BFD_INCLUDE=@BFD_INCLUDE@
+ BFD_LIB=@BFD_LIB@
+

phreaknet.1

@@ -305,6 +305,10 @@ Install chan_sip instead of or in addition to chan_pjsip.
 By default, chan_sip is not compiled or loaded since it is deprecated
 and will be removed in Asterisk 21.
 .TP
+\f[B]--alsa\f[R]
+Ensure ALSA library detection exists in the build system. This does
+NOT readd the deprecated/removed chan_alsa module.
+.TP
 \f[B]--cisco\f[R]
 Add full support for Cisco Call Manager phones using the usecallmanager
 patches (chan_sip only)

phreaknet.1.md

@@ -313,6 +313,9 @@ directories if necessary.
 **-s**, **--sip**
 : Install chan_sip instead of or in addition to chan_pjsip. By default, chan_sip is not compiled or loaded since it is deprecated and will be removed in Asterisk 21.
 
+**--alsa**
+: Ensure ALSA library detection exists in the build system. This does NOT readd the deprecated/removed chan_alsa module.
+
 **--cisco**
 : Add full support for Cisco Call Manager phones using the usecallmanager patches (chan_sip only)
 

phreaknet.sh

@@ -233,6 +233,7 @@ PATH="/sbin:$PATH" # in case su used without path
 AST_CC=1 # Country Code (default: 1 - NANPA)
 AST_USER=""
 EXTRA_FEATURES=1
+ALSA=0
 WEAK_TLS=0
 CHAN_SIP=0
 ENHANCED_CHAN_SIP=0
@@ -440,6 +441,7 @@ Options:
        --experimental install: Install experimental features that may not be production ready
        --fast         install: Compile as fast as possible
        --lightweight  install: Only install basic, required modules for basic Asterisk functionality
+       --alsa         install: Ensure ALSA library detection exists in the build system. This does NOT readd the deprecated/removed chan_alsa module.
        --cisco        install: Add full support for Cisco Call Manager phones (chan_sip only)
        --sccp         install: Install chan_sccp channel driver (Cisco Skinny)
        --drivers      install: Also install DAHDI drivers removed in 2018
@@ -2183,7 +2185,7 @@ else
 fi
 
 FLAG_TEST=0
-PARSED_ARGUMENTS=$(getopt -n phreaknet -o bc:u:dfhostu:v:w -l backtraces,cc:,dahdi,force,flag-test,help,sip,testsuite,user:,version:,weaktls,cisco,sccp,clli:,debug:,devmode,disa:,drivers,experimental,extcodecs,fast,freepbx,lightweight,api-key:,rotate,audit,boilerplate,upstream:,manselect,minimal,vanilla -- "$@")
+PARSED_ARGUMENTS=$(getopt -n phreaknet -o bc:u:dfhostu:v:w -l backtraces,cc:,dahdi,force,flag-test,help,sip,testsuite,user:,version:,weaktls,alsa,cisco,sccp,clli:,debug:,devmode,disa:,drivers,experimental,extcodecs,fast,freepbx,lightweight,api-key:,rotate,audit,boilerplate,upstream:,manselect,minimal,vanilla -- "$@")
 VALID_ARGUMENTS=$?
 if [ "$VALID_ARGUMENTS" != "0" ]; then
 	usage
@@ -2213,6 +2215,7 @@ while true; do
 		-u | --user ) AST_USER=$2; shift 2;;
 		-v | --version ) AST_ALT_VER=$2; shift 2;;
 		-w | --weaktls ) WEAK_TLS=1; shift ;;
+		--alsa ) ALSA=1; shift ;;
 		--audit ) PKG_AUDIT=1; shift ;;
 		--cisco ) SIP_CISCO=1; shift ;;
 		--sccp ) CHAN_SCCP=1; shift ;;
@@ -2299,6 +2302,8 @@ elif [ "$cmd" = "wizard" ]; then
 	dialog_result "$ans" "y" "--drivers"
 
 	# Channel Drivers
+	ans=$(dialog --nocancel --default-item 'n' --menu "Do you require ALSA library support?" 20 60 12 y Yes n No 2>&1 >/dev/tty)
+	dialog_result "$ans" "y" "--alsa"
 	ans=$(dialog --nocancel --default-item 'n' --menu "Do you need support for the deprecated chan_sip (SIP) module?" 20 60 12 y Yes n No 2>&1 >/dev/tty)
 	dialog_result "$ans" "y" "--sip"
 	ans=$(dialog --nocancel --default-item 'n' --menu "Do you want to install the chan_sccp (Skinny) channel driver?" 20 60 12 y Yes n No 2>&1 >/dev/tty)
@@ -2503,6 +2508,18 @@ elif [ "$cmd" = "install" ]; then
 		apt-get install -y libvpb1
 	fi
 	./contrib/scripts/install_prereq install
+
+	# Modify build system if needed
+	if [ "$ALSA" = "1" ]; then
+		# chan_alsa was removed in Asterisk 21, and with it, the support for ALSA lib detection in the build system. Add it back if needed.
+		lines=$(grep "HAVE_ALSA" include/asterisk/autoconfig.h | wc -l)
+		if [ $lines -eq 0 ]; then
+			printf "Patching build system to detect ALSA library\n"
+			git_patch "alsa.diff"
+			./bootstrap.sh # Regenerate configure and include/asterisk/autoconfig.h.in
+		fi
+	fi
+
 	if [ "$DEVMODE" = "1" ]; then
 		configure_devmode
 	else
@@ -2513,6 +2530,7 @@ elif [ "$cmd" = "install" ]; then
 	fi
 	cp contrib/scripts/voicemailpwcheck.py /usr/local/bin
 	chmod +x /usr/local/bin/voicemailpwcheck.py
+
 	# Change Compile Options: https://wiki.asterisk.org/wiki/display/AST/Using+Menuselect+to+Select+Asterisk+Options
 	$AST_MAKE menuselect.makeopts
 	menuselect/menuselect --enable format_mp3 menuselect.makeopts # add mp3 support