qmi, imsd-pcscf: read the ims PDN's P-CSCF list from the modem's runtime settings

The network hands the P-CSCF addresses to the modem in the PDN's Protocol
Configuration Options; ModemManager's bearer code does not ask the modem
for them, qmicli (libqmi 1.39) prints none of them, and libqmi has no TLV
for the IPv6 list (0x2E), which is why PCSCF= was a required setting. A
second QMI WDS client reads them once it is bound to the bearer's mux
data port (the binding ModemManager gives its own clients): Bind Mux
Data Port, Set IP Family 6, Get Current Settings, over one AF_QIPCRTR
socket. Imsd:Qmi holds the bytes and the readers (0x22 the flag, 0x23
IPv4, 0x24 FQDN, 0x2E IPv6 in Qualcomm's layout: a count, then 16 bytes
each); imsd-pcscf is the socket, the service lookup and the sequence, and
prints the list, one address per line; nothing runs it yet. It sends
no Start Network and no Stop Network; the bearer stayed connected and the
registration stood after its runs (the fp6 journal's probe capture 04,
benches 38 and 39). The
build, the CI cross-compile, the tarball and the apk gain the product;
linux-headers is named in the sysroot for <linux/qrtr.h>.

Tested: crafter-build test, 8 passed; the aarch64 build of this commit's
helper on the dev phone (KPN) against the live ims bearer.

packaging/APKBUILD.binary

@@ -45,6 +45,7 @@ package() {
     cd "$srcdir/imsd-$pkgver"
     install -Dm755 imsd "$pkgdir"/usr/bin/imsd
     install -Dm755 imsd-media "$pkgdir"/usr/libexec/imsd-media
+    install -Dm755 imsd-pcscf "$pkgdir"/usr/libexec/imsd-pcscf
     install -Dm755 imsd-dialerd "$pkgdir"/usr/bin/imsd-dialerd
     install -Dm755 ims-pdn-up.sh "$pkgdir"/usr/libexec/ims-pdn-up.sh
     install -Dm755 imsd-handover.sh "$pkgdir"/usr/libexec/imsd-handover.sh

packaging/build-package.sh

@@ -91,6 +91,7 @@ crafter-build -- $XTARGET
 crafter-build -- --product=media $XTARGET
 crafter-build -- --product=dialerd $XTARGET
 crafter-build -- --product=ofonod $XTARGET
+crafter-build -- --product=pcscf $XTARGET
 crafter-build test
 
 # --- bundle + package

packaging/make-bin-tarball.sh

@@ -12,10 +12,12 @@ BIN=$(ls -t bin/imsd-aarch64-*/imsd 2>/dev/null | head -n1)
 MEDIA=$(ls -t bin/imsd-media-aarch64-*/imsd-media 2>/dev/null | head -n1)
 DIALERD=$(ls -t bin/imsd-dialerd-aarch64-*/imsd-dialerd 2>/dev/null | head -n1)
 OFONOD=$(ls -t bin/imsd-ofonod-aarch64-*/imsd-ofonod 2>/dev/null | head -n1)
+PCSCF=$(ls -t bin/imsd-pcscf-aarch64-*/imsd-pcscf 2>/dev/null | head -n1)
 [ -n "$BIN" ] || { echo "no aarch64 imsd build found — cross-compile first" >&2; exit 1; }
 [ -n "$MEDIA" ] || { echo "no aarch64 imsd-media build — cross-compile with --product=media" >&2; exit 1; }
 [ -n "$DIALERD" ] || { echo "no aarch64 imsd-dialerd build — cross-compile with --product=dialerd" >&2; exit 1; }
 [ -n "$OFONOD" ] || { echo "no aarch64 imsd-ofonod build — cross-compile with --product=ofonod" >&2; exit 1; }
+[ -n "$PCSCF" ] || { echo "no aarch64 imsd-pcscf build — cross-compile with --product=pcscf" >&2; exit 1; }
 
 stage=$(mktemp -d)
 trap 'rm -rf "$stage"' EXIT
@@ -24,6 +26,7 @@ cp "$BIN" "$stage/imsd-$VER/imsd"
 cp "$MEDIA" "$stage/imsd-$VER/imsd-media"
 cp "$DIALERD" "$stage/imsd-$VER/imsd-dialerd"
 cp "$OFONOD" "$stage/imsd-$VER/imsd-ofonod"
+cp "$PCSCF" "$stage/imsd-$VER/imsd-pcscf"
 cp packaging/ims-pdn-up.sh packaging/imsd-handover.sh packaging/imsd.service \
    packaging/imsd-dialerd.desktop packaging/imsd-ofonod.service \
    packaging/imsd-ofono-restart-calls.sh \

packaging/make-sysroot.sh

@@ -4,7 +4,8 @@
 # make-sysroot.sh — build an Alpine aarch64 sysroot for cross-compiling imsd.
 #
 # Downloads apk-tools-static + the Alpine signing keys from the CDN and
-# populates a minimal rootfs (musl, libc++, glib and their headers) that
+# populates a minimal rootfs (musl, libc++, glib and their headers, the Linux
+# UAPI headers) that
 # clang can use via --sysroot. No root, no qemu, no device needed:
 #
 #   packaging/make-sysroot.sh [dir]        # default: ~/.cache/imsd/sysroot-aarch64-alpine
@@ -22,8 +23,10 @@ ARCH=aarch64
 # none): crafter-build compiles the sysroot's own copy first. --upgrade below
 # is for a run over an existing sysroot: added alone beside libc++ 22,
 # llvm-runtimes 23's source did not compile against its headers; upgraded
-# with it, it did.
-PKGS="musl-dev libc++ libc++-dev llvm-runtimes glib-dev compiler-rt llvm-libunwind-dev gcc"
+# with it, it did. linux-headers is in it for <linux/qrtr.h>, which
+# imsd-pcscf's QRTR socket needs (the sysroot had it only as another
+# package's dependency before).
+PKGS="musl-dev libc++ libc++-dev llvm-runtimes glib-dev compiler-rt llvm-libunwind-dev gcc linux-headers"
 
 work=$(mktemp -d)
 trap 'rm -rf "$work"' EXIT