imsd/implementations/main.cpp
Jorijn van der Graaf 6e77823933 imsd 0.2.7 — initial public snapshot
Userspace VoLTE/IMS daemon for mainline Linux phones (developed on the
Fairphone 6): a GLib-free core (SIP, SDP, USIM AKA, IPsec SA setup, RTP
media, call engine) behind a GDBus control daemon, a standalone AMR-WB
media leg, and a Plasma Dialer backend. C++26 modules built with Crafter
Build; the tree is clean under the project's house-style linter
(crafter-build lint) across all three build products.

Assisted-by: Claude:claude-fable-5
Signed-off-by: Jorijn van der Graaf <jorijnvdgraaf@catcrafts.net>
2026-07-22 23:04:21 +02:00

1451 lines
64 KiB
C++

// SPDX-License-Identifier: GPL-3.0-only
// SPDX-FileCopyrightText: Copyright (C) 2026 Catcrafts®
// lint-disable-file fixed-width-types no-char-pointer
/*
imsd — the userspace IMS/VoLTE daemon (control plane).
Owns net.catcrafts.IMS1 on the system bus with the project's frozen D-Bus ABI
(README) and drives it with the engine core: register on the IMS PDN (USIM AKA
+ IPsec sec-agree, fresh or warm-resume, with a keepalive re-REGISTER refresh),
run outgoing and incoming calls through the Imsd:Engine call machine (inbound
INVITEs on the protected-port listeners become ringing calls a dialer answers
via Accept), and spawn one imsd-media data-plane process per answered call.
GLib/GDBus lives only here; every message, digest, SA command, and call-state
decision comes from the GLib-free core.
Threads: a dedicated engine thread runs the SIP loop (blocking framed recv,
protected-port listeners, media reaping, keepalive); the GLib main loop owns
the bus. D-Bus method calls push commands to the engine queue; engine events
reach the bus via g_idle_add, where the calls table + status snapshot live
(touched only on the main thread).
--session own the name on the session bus (development; no policy needed)
*/
#include <arpa/inet.h>
#include <fcntl.h>
#include <gio/gio.h>
#include <glib-unix.h>
#include <netinet/in.h>
#include <poll.h>
#include <pthread.h>
#include <signal.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <unistd.h>
import std;
import Imsd;
namespace {
// ---- static config (env-overridable, same knobs as imsd.py) ---------------
constexpr const char* Version = "0.2.7";
constexpr const char* BusName = "net.catcrafts.IMS1";
constexpr const char* ObjPath = "/net/catcrafts/IMS1";
constexpr const char* Iface = "net.catcrafts.IMS1";
constexpr int PortUc = imsd::util::PortUc;
constexpr int PortUs = imsd::util::PortUs;
constexpr int InitPort = 5060;
std::string EnvOr(const char* k, std::string d) {
const char* v = std::getenv(k);
return v ? std::string(v) : std::move(d);
}
std::string SelfDir; // dir of argv[0], for locating imsd-media
void Log(std::string_view m) { std::println("imsd: {}", m); std::fflush(stdout); }
bool Is6(std::string_view a) { return a.contains(':'); }
// ---- subprocess exec ------------------------------------------------------
struct ProcResult { int rc = -1; std::string out; };
// Run argv, capture stdout (stderr discarded), wait. No shell.
ProcResult RunCapture(const std::vector<std::string>& argv) {
int pipefd[2];
if (pipe(pipefd) != 0) return {};
pid_t pid = fork();
if (pid == 0) {
dup2(pipefd[1], STDOUT_FILENO);
close(pipefd[0]); close(pipefd[1]);
int dn = open("/dev/null", O_WRONLY);
if (dn >= 0) { dup2(dn, STDERR_FILENO); close(dn); }
std::vector<char*> c;
for (auto& s : argv) c.push_back(const_cast<char*>(s.c_str()));
c.push_back(nullptr);
execvp(c[0], c.data());
_exit(127);
}
if (pid < 0) { close(pipefd[0]); close(pipefd[1]); return {}; }
close(pipefd[1]);
std::string out;
char buf[4096];
ssize_t n;
while ((n = read(pipefd[0], buf, sizeof buf)) > 0)
out.append(buf, static_cast<std::size_t>(n));
close(pipefd[0]);
int status = 0;
waitpid(pid, &status, 0);
return {WIFEXITED(status) ? WEXITSTATUS(status) : -1, std::move(out)};
}
// Run argv, discard output, return exit code.
int RunCmd(const std::vector<std::string>& argv) { return RunCapture(argv).rc; }
// ---- small text extractors (401 header params, qmicli "completed:") -------
std::optional<std::string> QuotedAfter(std::string_view text, std::string_view key) {
std::size_t at = text.find(key);
if (at == std::string_view::npos) return std::nullopt;
std::size_t start = at + key.size();
std::size_t end = text.find('"', start);
if (end == std::string_view::npos) return std::nullopt;
return std::string(text.substr(start, end - start));
}
std::optional<long> IntAfter(std::string_view text, std::string_view key) {
std::size_t at = text.find(key);
if (at == std::string_view::npos) return std::nullopt;
std::size_t i = at + key.size();
std::size_t start = i;
while (i < text.size() && text[i] >= '0' && text[i] <= '9') i++;
if (i == start) return std::nullopt;
long v = 0;
std::from_chars(text.data() + start, text.data() + i, v);
return v;
}
std::string EalgAfter(std::string_view ss) {
std::size_t at = ss.find("ealg=");
if (at == std::string_view::npos) return "null";
std::size_t i = at + 5;
std::size_t start = i;
auto ok = [](char c) { return (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '-'; };
while (i < ss.size() && ok(ss[i])) i++;
return std::string(ss.substr(start, i - start));
}
// value after "completed:" — integer or the hex ("AB:CD:..") token
std::optional<long> CompletedInt(std::string_view out) {
return IntAfter(out, "completed: ");
}
std::optional<std::string> CompletedHex(std::string_view out) {
std::size_t at = out.find("completed:");
if (at == std::string_view::npos) return std::nullopt;
std::size_t i = at + 10;
while (i < out.size() && (out[i] == ' ' || out[i] == '\t')) i++;
std::size_t start = i;
auto ok = [](char c) {
return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'F') ||
(c >= 'a' && c <= 'f') || c == ':';
};
while (i < out.size() && ok(out[i])) i++;
if (i == start) return std::nullopt;
std::string s(out.substr(start, i - start));
std::string h;
for (char c : s) if (c != ':') h.push_back(static_cast<char>(std::tolower(c)));
return h;
}
// global IPv6 on the ims PDN, from `ip -6 addr show dev <dev> scope global`.
std::optional<std::string> DetectLocal(const std::string& dev) {
auto r = RunCapture({"ip", "-6", "addr", "show", "dev", dev, "scope", "global"});
std::size_t at = r.out.find("inet6 ");
if (at == std::string_view::npos) return std::nullopt;
std::size_t start = at + 6;
std::size_t end = r.out.find('/', start);
if (end == std::string_view::npos) return std::nullopt;
return r.out.substr(start, end - start);
}
// ---- sockaddr helper ------------------------------------------------------
socklen_t MakeAddr(std::string_view ip, int port, sockaddr_storage& ss) {
std::memset(&ss, 0, sizeof ss);
std::string s(ip);
if (Is6(ip)) {
auto* a = reinterpret_cast<sockaddr_in6*>(&ss);
a->sin6_family = AF_INET6; a->sin6_port = htons(static_cast<uint16_t>(port));
inet_pton(AF_INET6, s.c_str(), &a->sin6_addr);
return sizeof(sockaddr_in6);
}
auto* a = reinterpret_cast<sockaddr_in*>(&ss);
a->sin_family = AF_INET; a->sin_port = htons(static_cast<uint16_t>(port));
inet_pton(AF_INET, s.c_str(), &a->sin_addr);
return sizeof(sockaddr_in);
}
// ---- SIP over the protected TCP flow --------------------------------------
class SipTcp {
public:
bool Connect(const std::string& local, int lport, const std::string& pcscf, int pport, int tries = 10) {
int fam = Is6(local) ? AF_INET6 : AF_INET;
for (int attempt = 0; attempt < tries; attempt++) {
int fd = socket(fam, SOCK_STREAM, 0);
if (fd < 0) return false;
int one = 1;
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
// REUSEPORT (paired with the listener's): a reconnect must bind
// the protected client port while the ServerPorts listener holds
// it in LISTEN state — REUSEADDR alone only covers TIME_WAIT.
setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof one);
sockaddr_storage la; socklen_t ll = MakeAddr(local, lport, la);
if (bind(fd, reinterpret_cast<sockaddr*>(&la), ll) != 0) { close(fd); return false; }
sockaddr_storage pa; socklen_t pl = MakeAddr(pcscf, pport, pa);
// non-blocking connect + poll: Linux connect() ignores SO_SNDTIMEO,
// so bound it ourselves (a silent P-CSCF must not hang the engine).
fcntl(fd, F_SETFL, O_NONBLOCK);
int rc = connect(fd, reinterpret_cast<sockaddr*>(&pa), pl);
bool connected = (rc == 0);
if (rc < 0 && errno == EINPROGRESS) {
pollfd p{fd, POLLOUT, 0};
if (poll(&p, 1, 12000) > 0) {
int err = 0; socklen_t el = sizeof err;
getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &el);
connected = (err == 0);
}
}
if (connected) {
fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
fd_ = fd; alive_ = true; fb_ = {};
return true;
}
close(fd);
if (attempt == tries - 1) return false;
Log(std::format("connect failed; retry in 10s (TIME_WAIT?) [{}/{}]", attempt + 1, tries));
sleep(10);
}
return false;
}
// MSG_NOSIGNAL: a flow the network killed (CSFB excursion, P-CSCF idle
// drop) must surface as a send error, not a SIGPIPE.
bool Send(std::string_view msg) {
std::size_t off = 0;
while (off < msg.size()) {
ssize_t w = send(fd_, msg.data() + off, msg.size() - off, MSG_NOSIGNAL);
if (w <= 0) { alive_ = false; return false; }
off += static_cast<std::size_t>(w);
}
return true;
}
void SendKeepalive() {
if (send(fd_, "\r\n\r\n", 4, MSG_NOSIGNAL) <= 0) alive_ = false;
}
std::optional<std::string> RecvMsg(double timeoutSec) {
auto deadline = std::chrono::steady_clock::now() +
std::chrono::duration_cast<std::chrono::steady_clock::duration>(std::chrono::duration<double>(timeoutSec));
for (;;) {
if (auto m = fb_.TryExtract()) return m;
auto now = std::chrono::steady_clock::now();
if (now >= deadline) return std::nullopt;
int ms = static_cast<int>(std::chrono::duration_cast<std::chrono::milliseconds>(deadline - now).count());
pollfd p{fd_, POLLIN, 0};
int r = poll(&p, 1, ms);
if (r <= 0) { if (r == 0) return std::nullopt; if (errno == EINTR) continue; return std::nullopt; }
char buf[65535];
ssize_t n = recv(fd_, buf, sizeof buf, 0);
// EOF/RST is not a timeout: mark the flow dead so the engine's
// reconnect path notices within one loop turn instead of at the
// next (possibly 30-min-away) keepalive refresh.
if (n <= 0) { alive_ = false; return std::nullopt; }
fb_.Append(std::string_view(buf, static_cast<std::size_t>(n)));
}
}
int Fd() const { return fd_; }
bool Alive() const { return fd_ >= 0 && alive_; }
void Close() { if (fd_ >= 0) { close(fd_); fd_ = -1; } alive_ = false; }
private:
int fd_ = -1;
bool alive_ = false;
imsd::sip::FrameBuffer fb_;
};
// ---- protected-port listeners (terminating requests: remote BYE/UPDATE) ---
struct Inbound {
std::string msg;
std::function<void(const std::string&)> reply;
};
class ServerPorts {
public:
void Open(const std::string& local) {
int fam = Is6(local) ? AF_INET6 : AF_INET;
for (int port : {PortUc, PortUs}) {
int ls = socket(fam, SOCK_STREAM, 0);
if (ls >= 0) {
int one = 1;
setsockopt(ls, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
// paired with SipTcp::Connect's REUSEPORT (reconnect binds
// the client port while this listener holds it)
setsockopt(ls, SOL_SOCKET, SO_REUSEPORT, &one, sizeof one);
sockaddr_storage a; socklen_t l = MakeAddr(local, port, a);
if (bind(ls, reinterpret_cast<sockaddr*>(&a), l) == 0 && listen(ls, 4) == 0) {
fcntl(ls, F_SETFL, O_NONBLOCK);
listeners_.push_back(ls);
} else { close(ls); }
}
int us = socket(fam, SOCK_DGRAM, 0);
if (us >= 0) {
int one = 1;
setsockopt(us, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
sockaddr_storage a; socklen_t l = MakeAddr(local, port, a);
if (bind(us, reinterpret_cast<sockaddr*>(&a), l) == 0) {
fcntl(us, F_SETFL, O_NONBLOCK);
udp_.push_back(us);
if (port == PortUc) udpUc_ = us;
} else { close(us); }
}
Log(std::format("listening on protected port {} (TCP+UDP)", port));
}
}
std::vector<Inbound> Poll() {
std::vector<Inbound> out;
for (int ls : listeners_) {
for (;;) {
int c = accept(ls, nullptr, nullptr);
if (c < 0) break;
fcntl(c, F_SETFL, O_NONBLOCK);
conns_.push_back({c, {}});
}
}
for (int us : udp_) {
for (;;) {
char buf[65535];
sockaddr_storage src; socklen_t sl = sizeof src;
ssize_t n = recvfrom(us, buf, sizeof buf, 0, reinterpret_cast<sockaddr*>(&src), &sl);
if (n <= 0) break;
std::string_view sv(buf, static_cast<std::size_t>(n));
bool blank = sv.find_first_not_of("\r\n \t") == std::string_view::npos;
if (blank) continue;
std::string msg(sv);
if (!imsd::sip::Status(msg).has_value()) { // request only
sockaddr_storage s = src; socklen_t sll = sl;
int rs = us;
// RFC 3261 18.2.2: rport-less UDP requests get their
// response at the Via sent-by port, not the source
// port. KPN's P-CSCF sends in-dialog requests from its
// protected client port but silently drops responses
// sent back there (s57: every UPDATE/BYE 200 ignored,
// audit kills the call); the Via port is its protected
// server port, whose SA pairs with OUR client-port
// socket — respond from that one so the uc->ps SA
// carries it.
if (auto vp = imsd::sip::ViaResponsePort(msg)) {
if (s.ss_family == AF_INET6)
reinterpret_cast<sockaddr_in6*>(&s)->sin6_port =
htons(static_cast<uint16_t>(*vp));
else
reinterpret_cast<sockaddr_in*>(&s)->sin_port =
htons(static_cast<uint16_t>(*vp));
if (udpUc_ >= 0) rs = udpUc_;
}
out.push_back({std::move(msg), [rs, s, sll](const std::string& r) mutable {
sendto(rs, r.data(), r.size(), 0, reinterpret_cast<sockaddr*>(&s), sll);
}});
}
}
}
for (auto it = conns_.begin(); it != conns_.end();) {
bool eof = false;
for (;;) {
char buf[65535];
ssize_t n = recv(it->fd, buf, sizeof buf, 0);
if (n == 0) { eof = true; break; }
if (n < 0) break;
it->fb.Append(std::string_view(buf, static_cast<std::size_t>(n)));
}
while (auto m = it->fb.TryExtract()) {
if (!imsd::sip::Status(*m).has_value()) {
int fd = it->fd;
out.push_back({*m, [fd](const std::string& r) {
(void)!write(fd, r.data(), r.size());
}});
}
}
if (eof) { close(it->fd); it = conns_.erase(it); } else { ++it; }
}
return out;
}
void CloseAll() {
for (int f : listeners_) close(f);
for (int f : udp_) close(f);
for (auto& c : conns_) close(c.fd);
listeners_.clear(); udp_.clear(); conns_.clear();
}
private:
struct Conn { int fd; imsd::sip::FrameBuffer fb; };
int udpUc_ = -1;
std::vector<int> listeners_, udp_;
std::vector<Conn> conns_;
};
// ---- registration state ---------------------------------------------------
struct RegState {
std::string callid, ftag;
long cseq = 2;
std::uint32_t spiUc = 0;
std::uint32_t spiUs = 0;
long expiry = 0;
int slot = 0;
std::string aid;
// Contact user-part of the stored binding (UUID since the s53 oracle
// diff; empty = legacy IMSI binding from an older state file).
std::string contactUser;
};
// Writable directory for the daemon's own files: the persisted registration
// context, media stats, and optional debug dumps. Root daemon (the packaged
// service): /var/lib/imsd; --session/dev runs: the XDG state dir.
std::string StateDir() {
if (geteuid() == 0) return "/var/lib/imsd";
if (const char* x = std::getenv("XDG_STATE_HOME")) return std::format("{}/imsd", std::string(x));
return std::format("{}/.local/state/imsd", EnvOr("HOME", "/tmp"));
}
// tiny JSON reader/writer for the persisted registration context.
std::string StatePath() { return EnvOr("STATE_FILE", std::format("{}/imsreg.state", StateDir())); }
void PersistState(const RegState& r, const std::string& route, const std::string& ppi) {
std::string j = std::format(
"{{\"callid\": \"{}\", \"ftag\": \"{}\", \"cseq\": {}, \"spi_uc\": {}, "
"\"spi_us\": {}, \"expiry\": {}, \"route\": \"{}\", \"ppi\": \"{}\", "
"\"contact_user\": \"{}\"}}",
r.callid, r.ftag, r.cseq, r.spiUc, r.spiUs, r.expiry, route, ppi,
r.contactUser);
std::string path = StatePath();
std::error_code ec;
std::filesystem::create_directories(std::filesystem::path(path).parent_path(), ec);
if (std::FILE* f = std::fopen(path.c_str(), "w")) {
std::fwrite(j.data(), 1, j.size(), f);
std::fclose(f);
}
}
// Raw dump of a received message for offline diffing against the stock-modem
// oracle (rung-5b registration-parity work). One file per message kind,
// overwritten on every registration cycle. The dumps carry the subscriber's
// IMSI/MSISDN and addresses, so they are opt-in (DUMP_SIP=1) and mode 0600.
void DumpRaw(std::string_view name, std::string_view msg) {
if (EnvOr("DUMP_SIP", "0") != "1") return;
std::string path = std::format("{}/{}", EnvOr("DUMP_DIR", StateDir()), name);
int fd = open(path.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0600);
if (fd < 0) return;
(void)!write(fd, msg.data(), msg.size());
close(fd);
}
struct PersistedState {
std::optional<std::string> callid, ftag, route, ppi, contactUser;
std::optional<long> cseq, spiUc, spiUs, expiry;
};
std::optional<PersistedState> LoadState() {
std::FILE* f = std::fopen(StatePath().c_str(), "r");
if (!f) return std::nullopt;
std::string s;
char buf[1024]; std::size_t n;
while ((n = std::fread(buf, 1, sizeof buf, f)) > 0) s.append(buf, n);
std::fclose(f);
PersistedState ps;
ps.callid = QuotedAfter(s, "\"callid\": \"");
ps.ftag = QuotedAfter(s, "\"ftag\": \"");
ps.route = QuotedAfter(s, "\"route\": \"");
ps.ppi = QuotedAfter(s, "\"ppi\": \"");
ps.contactUser = QuotedAfter(s, "\"contact_user\": \"");
ps.cseq = IntAfter(s, "\"cseq\": ");
ps.spiUc = IntAfter(s, "\"spi_uc\": ");
ps.spiUs = IntAfter(s, "\"spi_us\": ");
ps.expiry = IntAfter(s, "\"expiry\": ");
return ps;
}
// ---- daemon-level shared state (main thread only) -------------------------
struct CallInfo {
std::string uni, number, state, reason;
std::int64_t startedAt = 0;
std::int64_t answeredAt = 0;
std::string direction = "outgoing";
};
struct StatusSnapshot {
bool registered = false;
std::string local, pcscf, ppi;
std::int64_t expiry = 0;
std::int64_t cseq = 0;
};
// engine -> main-loop event
struct Event {
enum class Type { Added, State, Deleted, Registration, Status, Fatal } type;
CallInfo info; // Added
std::string uni, state, reason; // State/Deleted
StatusSnapshot status; // Registration/Status
std::string text; // Fatal
};
GDBusConnection* DbusConn = nullptr;
std::map<std::string, CallInfo> Calls; // main thread only
StatusSnapshot StatusSnap; // main thread only
GMainLoop* MainLoop = nullptr;
std::int64_t NowEpoch() {
return std::chrono::duration_cast<std::chrono::seconds>(std::chrono::system_clock::now().time_since_epoch()).count();
}
// build an a{sv} from a CallInfo (matches imsd.py _d typing)
GVariant* CallVariant(const CallInfo& c) {
GVariantBuilder b;
g_variant_builder_init(&b, G_VARIANT_TYPE("a{sv}"));
g_variant_builder_add(&b, "{sv}", "uni", g_variant_new_string(c.uni.c_str()));
g_variant_builder_add(&b, "{sv}", "number", g_variant_new_string(c.number.c_str()));
g_variant_builder_add(&b, "{sv}", "state", g_variant_new_string(c.state.c_str()));
g_variant_builder_add(&b, "{sv}", "reason", g_variant_new_string(c.reason.c_str()));
g_variant_builder_add(&b, "{sv}", "startedAt", g_variant_new_int64(c.startedAt));
g_variant_builder_add(&b, "{sv}", "answeredAt", g_variant_new_int64(c.answeredAt));
g_variant_builder_add(&b, "{sv}", "direction", g_variant_new_string(c.direction.c_str()));
return g_variant_builder_end(&b);
}
void EmitSignal(const char* name, GVariant* params) {
if (!DbusConn) return;
g_dbus_connection_emit_signal(DbusConn, nullptr, ObjPath, Iface, name, params, nullptr);
}
gboolean OnIdleEvent(gpointer data) {
std::unique_ptr<Event> ev(static_cast<Event*>(data));
switch (ev->type) {
case Event::Type::Added: {
Calls[ev->info.uni] = ev->info;
EmitSignal("CallAdded", g_variant_new("(s@a{sv})", ev->info.uni.c_str(), CallVariant(ev->info)));
break;
}
case Event::Type::State: {
auto it = Calls.find(ev->uni);
if (it != Calls.end()) {
it->second.state = ev->state;
it->second.reason = ev->reason;
if (ev->state == "active" && it->second.answeredAt == 0) it->second.answeredAt = NowEpoch();
}
EmitSignal("CallStateChanged", g_variant_new("(sss)", ev->uni.c_str(), ev->state.c_str(), ev->reason.c_str()));
break;
}
case Event::Type::Deleted:
Calls.erase(ev->uni);
EmitSignal("CallDeleted", g_variant_new("(s)", ev->uni.c_str()));
break;
case Event::Type::Registration:
StatusSnap = ev->status;
EmitSignal("RegistrationChanged", g_variant_new("(b)", ev->status.registered ? TRUE : FALSE));
break;
case Event::Type::Status:
StatusSnap = ev->status;
break;
case Event::Type::Fatal:
Log(std::format("engine fatal: {} — exiting for systemd restart", ev->text));
g_main_loop_quit(MainLoop);
break;
}
return G_SOURCE_REMOVE;
}
void PostEvent(std::unique_ptr<Event> ev) {
g_idle_add(OnIdleEvent, ev.release());
}
// ================= engine ==================================================
class Engine {
public:
Engine() {
// No baked-in default: the P-CSCF is carrier infrastructure, learned
// from the IMS PDN's PCO on a stock stack. Until PCO discovery is
// implemented, PCSCF= must be configured (see README).
pcscf_ = EnvOr("PCSCF", "");
pcscfPort_ = std::atoi(EnvOr("PCSCF_PORT", "5060").c_str());
dev_ = EnvOr("DEV", "qmapmux0.0");
outDir_ = EnvOr("OUT_DIR", StateDir());
rtpPort_ = std::atoi(EnvOr("RTP_PORT", "50004").c_str());
precond_ = EnvOr("PRECOND", "0") == "1";
ealgOffer_ = EnvOr("EALG", "aes-cbc");
mediaBin_ = ResolveMediaBin();
}
void SetLocal(std::string l) { local_ = std::move(l); }
void SetDevMode(bool d) { devMode_ = d; }
const std::string& Local() const { return local_; }
// Dial() runs on the D-Bus thread: allocate the uni, queue the work.
std::string Dial(const std::string& number) {
std::scoped_lock g(cmdLock_);
std::string uni = std::format("ims-call-{}", ++callSeq_);
cmds_.push_back({Cmd::Kind::Dial, uni, number});
return uni;
}
void HangUp(const std::string& uni) {
std::scoped_lock g(cmdLock_);
cmds_.push_back({Cmd::Kind::HangUp, uni, {}});
}
void Accept(const std::string& uni) {
std::scoped_lock g(cmdLock_);
cmds_.push_back({Cmd::Kind::Accept, uni, {}});
}
void Stop() {
{ std::scoped_lock g(cmdLock_); cmds_.push_back({Cmd::Kind::Stop, {}, {}}); }
quit_.store(true);
}
void Run() {
try {
BringUp();
} catch (const std::exception& e) {
if (devMode_) {
// dev/session mode (no modem): keep the ABI up, unregistered,
// so the D-Bus surface can be exercised without a phone.
Log(std::format("bring-up skipped (dev mode): {}", e.what()));
registered_ = false;
EmitStatus(true);
DevLoop();
return;
}
Log(std::format("bring-up FAILED: {}", e.what()));
auto ev = std::make_unique<Event>();
ev->type = Event::Type::Fatal; ev->text = e.what();
PostEvent(std::move(ev));
return;
}
registered_ = true;
EmitStatus(true);
lastRefresh_ = Mono();
lastKa_ = Mono();
try { server_.Open(local_); }
catch (...) { Log("server ports unavailable; remote hangup/incoming not seen"); }
SubscribeRegEvent();
while (!quit_.load()) {
if (auto cmd = PopCmd()) { HandleCmd(*cmd); continue; }
for (Inbound& in : server_.Poll()) {
reply_ = in.reply;
DispatchRequest(in.msg);
}
MaybeRefresh();
MaybeReconnect();
if (!call_ && sip_.Alive() && Mono() - lastKa_ > 30) { sip_.SendKeepalive(); lastKa_ = Mono(); }
ReapMedia();
if (call_ && call_->State() != imsd::engine::CallState::Active && Mono() > deadline_) {
Execute(call_->OnDeadline());
MaybeDropCall();
}
auto msg = sip_.RecvMsg(0.3);
if (!msg) continue;
auto st = imsd::sip::Status(*msg);
if (!st) { reply_ = [this](const std::string& r) { sip_.Send(r); }; DispatchRequest(*msg); continue; }
std::string cseq(imsd::sip::Header(*msg, "CSeq").value_or(""));
std::string callid(imsd::sip::Header(*msg, "Call-ID").value_or(""));
if (call_ && callid == call_->CallId() && cseq.ends_with("INVITE")) {
Execute(call_->OnInviteResponse(*msg));
MaybeDropCall();
} else if (!subCallid_.empty() && callid == subCallid_ && cseq.ends_with("SUBSCRIBE")) {
Log(std::format("reg-event SUBSCRIBE -> {}", *st));
DumpRaw("imsd-subscribe-200.raw", *msg);
}
}
// shutdown: release an active call, keep the SA/registration for resume
if (call_) { Execute(call_->OnHangup()); MaybeDropCall(); }
sip_.Close();
Log("engine stopped (SA left up for resume)");
}
private:
struct Cmd { enum class Kind { Dial, HangUp, Accept, Stop } kind; std::string uni, number; };
// dev/session mode without a modem: process commands so the ABI answers,
// but there is no SIP socket — a Dial collapses to terminated/error.
void DevLoop() {
while (!quit_.load()) {
if (auto cmd = PopCmd()) { HandleCmd(*cmd); MaybeDropCall(); continue; }
std::this_thread::sleep_for(std::chrono::milliseconds(200));
}
}
// config
std::string pcscf_, dev_, outDir_, local_, ealgOffer_, mediaBin_;
int pcscfPort_ = 5060;
int rtpPort_ = 50004;
bool precond_ = false;
// registration
imsd::msg::Context ctx_;
RegState reg_;
std::string route_, ppi_, ss_;
bool registered_ = false;
SipTcp sip_;
ServerPorts server_;
std::string subCallid_; // live reg-event subscription dialog (empty: none)
int portPs_ = 0; // P-CSCF protected server port (reconnect target)
double nextReconnect_ = 0;
double reconnectDelay_ = 5;
// call
imsd::util::Rng rng_;
std::optional<imsd::engine::CallMachine> call_;
bool dropCall_ = false;
pid_t mediaPid_ = -1;
double deadline_ = 0;
// reply_ answers the inbound request being dispatched right now;
// callReply_ is the call's durable response channel — refreshed from
// reply_ on every in-dialog request, so an Accept()'s 200 OK (which
// happens outside any inbound dispatch) still reaches the caller.
std::function<void(const std::string&)> reply_;
std::function<void(const std::string&)> callReply_;
// timers
double lastRefresh_ = 0;
double lastKa_ = 0;
std::atomic<bool> quit_{false};
bool devMode_ = false;
// command queue
std::mutex cmdLock_;
std::deque<Cmd> cmds_;
// atomic: Dial (D-Bus thread) and an inbound INVITE (engine thread) both mint unis
std::atomic<std::uint64_t> callSeq_{0};
static double Mono() {
return std::chrono::duration<double>(std::chrono::steady_clock::now().time_since_epoch()).count();
}
std::optional<Cmd> PopCmd() {
std::scoped_lock g(cmdLock_);
if (cmds_.empty()) return std::nullopt;
Cmd c = cmds_.front(); cmds_.pop_front();
return c;
}
static std::string ResolveMediaBin() {
if (const char* e = std::getenv("IMSD_MEDIA")) return e;
if (!SelfDir.empty()) {
std::string p = std::format("{}/imsd-media", SelfDir);
if (access(p.c_str(), X_OK) == 0) return p;
}
return "/usr/libexec/imsd-media";
}
// Refresh P-Access-Network-Info from the live serving cell (mmcli 3GPP
// location). Serving cell changes as the phone moves, so this runs
// before every REGISTER/INVITE-carrying step; on failure the previous
// value (possibly empty = header omitted) stays.
void RefreshPani() {
auto loc = RunCapture({"mmcli", "-m", "any", "--location-get"});
if (auto p = imsd::aka::ParsePani(loc.out)) ctx_.panInfo = *p;
}
// ---- bring-up: warm resume if an SA + state file exist, else fresh ----
void BringUp() {
if (pcscf_.empty()) throw std::runtime_error("PCSCF not set — configure the carrier's P-CSCF address " "(P-CSCF discovery from the PDN's PCO is not implemented yet)");
auto card = RunCapture({"qmicli", "-d", "qrtr://0", "--uim-get-card-status"});
auto sel = imsd::aka::ParseCardStatus(card.out);
if (!sel) throw std::runtime_error("no ready USIM found");
auto modem = RunCapture({"mmcli", "-m", "any"});
auto simPath = imsd::aka::ParsePrimarySimPath(modem.out);
if (!simPath) throw std::runtime_error("no primary SIM path");
auto siminfo = RunCapture({"mmcli", "-i", *simPath});
auto info = imsd::aka::ParseSimInfo(siminfo.out);
if (!info) throw std::runtime_error("SIM IMSI/operator not found");
ctx_.id = imsd::aka::MakeIdentity(info->imsi, info->mcc, info->mnc);
ctx_.local = local_;
ctx_.ealgOffer = ealgOffer_;
// USER_AGENT overrides (some networks fingerprint UAs — setting the
// stock firmware's build string gives oracle parity, journal/ims.md
// s53); USER_AGENT= (empty) omits the header.
ctx_.userAgent = EnvOr("USER_AGENT", std::format("imsd/{}", Version));
if (auto imei = imsd::aka::ParseEquipmentId(modem.out))
if (auto urn = imsd::aka::ImeiUrn(*imei)) ctx_.instanceId = *urn;
reg_.slot = sel->slot;
reg_.aid = sel->aid;
Log(std::format("SIM slot={} IMSI={} domain={}", sel->slot, info->imsi, ctx_.id.domain));
RefreshPani();
std::string resume = EnvOr("RESUME", "auto");
if (resume != "0" && TryResume()) return;
FreshRegister();
}
bool TryResume() {
auto state = RunCapture({"ip", "xfrm", "state"});
auto policy = RunCapture({"ip", "xfrm", "policy"});
auto sa = imsd::ipsec::ParseExistingSa(state.out, policy.out, pcscf_, local_);
if (!sa) return false;
auto ps = LoadState();
if (!ps || !ps->callid) { Log("no reg state file; resume falls back to fresh"); return false; }
route_ = ps->route.value_or(std::format("<sip:{};lr>", imsd::util::HostPort(pcscf_, sa->portPs)));
// No fallback identity: an empty ppi omits P-Preferred-Identity and
// is re-learned from the next 200's P-Associated-URI.
ppi_ = ps->ppi.value_or("");
ss_ = sa->securityServer;
ctx_.route = route_; ctx_.ppi = ppi_; ctx_.securityServer = ss_;
ctx_.portUc = PortUc; ctx_.portUs = PortUs;
Log(std::format("RESUME via existing SA (cseq {})", ps->cseq.value_or(1)));
portPs_ = sa->portPs;
if (!sip_.Connect(local_, PortUc, pcscf_, sa->portPs)) {
Log("resume connect failed; falling back to fresh");
return false;
}
reg_.callid = *ps->callid;
reg_.ftag = ps->ftag.value_or("");
// The refresh must carry the SAME Contact URI as the stored binding;
// an absent key means the binding predates the oracle diff and used
// the IMSI (the empty-contactUser fallback).
reg_.contactUser = ps->contactUser.value_or("");
ctx_.contactUser = reg_.contactUser;
reg_.cseq = ps->cseq.value_or(1);
reg_.spiUc = static_cast<std::uint32_t>(ps->spiUc.value_or(sa->spiUc));
reg_.spiUs = static_cast<std::uint32_t>(ps->spiUs.value_or(sa->spiUs));
reg_.expiry = ps->expiry.value_or(0);
auto [okMsg, used] = Reregister(reg_.callid, reg_.ftag, reg_.cseq + 1, reg_.spiUc, reg_.spiUs);
reg_.cseq = used;
if (auto e = imsd::sip::GrantedExpires(okMsg)) reg_.expiry = *e;
UpdateRouteAndPpi(okMsg);
LogBindings(okMsg);
PersistState(reg_, route_, ppi_);
Log("REGISTERED (resumed + true-refreshed)");
return true;
}
// The registrar's 200 OK echoes EVERY current binding for the implicit
// set — the network's own view. Log them: a stale binding at a dead
// SLAAC address is still tried by terminating routing until it expires.
void LogBindings(const std::string& ok) {
for (auto ct : imsd::sip::Headers(ok, "Contact"))
Log(std::format("binding: {}", ct));
}
void FreshRegister() {
Log("FRESH registration");
// Oracle diff (journal/ims.md s53): stock's Contact user-part is a
// fresh UUID per registration, not the IMSI. Minted before reg1 so
// both REGISTERs and the stored binding carry the same URI.
reg_.contactUser = imsd::util::Uuid4(rng_);
ctx_.contactUser = reg_.contactUser;
Log(std::format("contact user-part: {}", reg_.contactUser));
std::string callidReg = std::format("{}@{}", rng_.Token(16), local_);
std::string ftag = rng_.Token(8);
std::uint32_t spiUc = rng_.UInt(0x10000, 0xFFFFFFF);
std::uint32_t spiUs = rng_.UInt(0x10000, 0xFFFFFFF);
ctx_.portUc = PortUc; ctx_.portUs = PortUs; ctx_.initPort = InitPort;
// reg1 over UDP from the init port -> 401
int fam = Is6(local_) ? AF_INET6 : AF_INET;
int us = socket(fam, SOCK_DGRAM, 0);
int one = 1; setsockopt(us, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
sockaddr_storage la; socklen_t ll = MakeAddr(local_, InitPort, la);
if (bind(us, reinterpret_cast<sockaddr*>(&la), ll) != 0) {
close(us); throw std::runtime_error("bind init port failed");
}
timeval tv{8, 0}; setsockopt(us, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof tv);
std::string reg1 = imsd::msg::BuildRegisterInitial(ctx_, callidReg, ftag, rng_.Token(16), spiUc, spiUs);
sockaddr_storage pa; socklen_t pl = MakeAddr(pcscf_, pcscfPort_, pa);
sendto(us, reg1.data(), reg1.size(), 0, reinterpret_cast<sockaddr*>(&pa), pl);
char buf[65535];
ssize_t n = recv(us, buf, sizeof buf, 0);
close(us);
if (n <= 0) throw std::runtime_error("no 401 to unprotected REGISTER");
std::string resp(buf, static_cast<std::size_t>(n));
if (imsd::sip::Status(resp) != 401) throw std::runtime_error("expected 401");
auto nonceB64 = QuotedAfter(resp, "nonce=\"");
if (!nonceB64) throw std::runtime_error("no nonce in 401");
auto raw = imsd::util::FromBase64(*nonceB64);
if (!raw || raw->size() < 32) throw std::runtime_error("bad nonce");
std::vector<std::uint8_t> rand16(raw->begin(), raw->begin() + 16);
std::vector<std::uint8_t> autn16(raw->begin() + 16, raw->begin() + 32);
auto ssv = imsd::sip::Header(resp, "Security-Server");
if (!ssv) throw std::runtime_error("no Security-Server");
ss_ = std::string(*ssv);
int portPs = static_cast<int>(IntAfter(ss_, "port-s=").value_or(0));
int portPc = static_cast<int>(IntAfter(ss_, "port-c=").value_or(0));
std::uint32_t spiPs = static_cast<std::uint32_t>(IntAfter(ss_, "spi-s=").value_or(0));
std::uint32_t spiPc = static_cast<std::uint32_t>(IntAfter(ss_, "spi-c=").value_or(0));
std::string ealg = EalgAfter(ss_);
if (spiPs == 0) throw std::runtime_error("fresh-SA throttle active (spi-s=0); retry later");
auto aka = Authenticate(rand16, autn16);
if (!aka) throw std::runtime_error("USIM AKA failed");
// install the IPsec SA pair
imsd::ipsec::SaParams sp;
sp.local = local_; sp.pcscf = pcscf_;
sp.ik = aka->ik; sp.ck = aka->ck;
sp.spiUc = spiUc; sp.spiUs = spiUs; sp.spiPc = spiPc; sp.spiPs = spiPs;
sp.portUc = PortUc; sp.portUs = PortUs; sp.portPs = portPs; sp.portPc = portPc;
sp.ealg = ealg;
for (auto& cmd : imsd::ipsec::BuildSetupCommands(sp))
RunCmd(cmd);
ctx_.securityServer = ss_;
portPs_ = portPs;
if (!sip_.Connect(local_, PortUc, pcscf_, portPs)) throw std::runtime_error("protected TCP connect failed");
std::string cnonce = rng_.Token(16);
std::string response = imsd::aka::DigestAkav1(*nonceB64, aka->res, cnonce, ctx_.id.regUri, ctx_.id.impi, ctx_.id.domain);
std::string auth = imsd::msg::AuthAka(ctx_, *nonceB64, cnonce, response);
std::string reg2 = imsd::msg::BuildRegisterProtected(ctx_, callidReg, ftag, rng_.Token(16), 2, spiUc, spiUs, auth);
if (!sip_.Send(reg2)) throw std::runtime_error("send protected REGISTER failed");
std::string ok;
for (;;) {
auto m = sip_.RecvMsg(12.0);
if (!m) throw std::runtime_error("no reply to protected REGISTER");
auto st = imsd::sip::Status(*m);
if (st == 200) { ok = *m; break; }
if (st && *st >= 300) throw std::runtime_error(std::format("REGISTER failed {}", *st));
}
reg_.callid = callidReg; reg_.ftag = ftag; reg_.cseq = 2;
reg_.spiUc = spiUc; reg_.spiUs = spiUs;
reg_.expiry = imsd::sip::GrantedExpires(ok).value_or(0);
DumpRaw("imsd-register-200.raw", ok);
UpdateRouteAndPpi(ok);
LogBindings(ok);
if (route_.empty()) route_ = std::format("<sip:{};lr>", imsd::util::HostPort(pcscf_, portPs));
ctx_.route = route_; ctx_.ppi = ppi_;
PersistState(reg_, route_, ppi_);
Log("REGISTERED (fresh)");
}
// re-REGISTER over the (resumed or live) SA. Returns (200 msg, used cseq).
std::pair<std::string, long> Reregister(const std::string& callid, const std::string& ftag, long startCseq, std::uint32_t spiUc, std::uint32_t spiUs) {
std::string auth = imsd::msg::AuthEmpty(ctx_);
long cseq = startCseq;
bool challenged = false;
for (;;) {
std::string reg = imsd::msg::BuildRegisterProtected(ctx_, callid, ftag, rng_.Token(16), cseq, spiUc, spiUs, auth);
if (!sip_.Send(reg)) throw std::runtime_error("send re-REGISTER failed");
auto m = sip_.RecvMsg(12.0);
if (!m) throw std::runtime_error("no reply to re-REGISTER");
auto st = imsd::sip::Status(*m);
if (st == 200) return {*m, cseq};
if (st == 401 && !challenged) {
challenged = true;
auto nonce = QuotedAfter(*m, "nonce=\"");
auto raw = nonce ? imsd::util::FromBase64(*nonce) : std::nullopt;
if (!raw || raw->size() < 32) throw std::runtime_error("bad 401 nonce on refresh");
std::vector<std::uint8_t> rnd(raw->begin(), raw->begin() + 16);
std::vector<std::uint8_t> autn(raw->begin() + 16, raw->begin() + 32);
auto aka = Authenticate(rnd, autn);
if (!aka) throw std::runtime_error("AKA failed on refresh");
std::string cnonce = rng_.Token(16);
std::string response = imsd::aka::DigestAkav1(*nonce, aka->res, cnonce, ctx_.id.regUri, ctx_.id.impi, ctx_.id.domain);
auth = imsd::msg::AuthAka(ctx_, *nonce, cnonce, response);
cseq++;
continue;
}
throw std::runtime_error(std::format("re-REGISTER failed {}", st.value_or(0)));
}
}
void UpdateRouteAndPpi(const std::string& okMsg) {
auto svc = imsd::sip::Headers(okMsg, "Service-Route");
if (svc.empty()) Log("200: no Service-Route (route stays P-CSCF)");
if (!svc.empty()) {
std::string r;
for (std::size_t i = 0; i < svc.size(); i++) { r += svc[i]; if (i + 1 < svc.size()) r += ", "; }
route_ = r; ctx_.route = r;
Log(std::format("200 Service-Route: {}", r));
}
for (auto p : imsd::sip::Headers(okMsg, "Path"))
Log(std::format("200 Path: {}", p));
auto pau = imsd::sip::Headers(okMsg, "P-Associated-URI");
if (pau.empty()) Log("200: NO P-Associated-URI");
for (auto a : pau)
Log(std::format("200 P-Associated-URI: {}", a));
for (auto a : imsd::sip::Headers(okMsg, "P-Associated-URI")) {
std::size_t lt = a.find("<tel:");
if (lt != std::string_view::npos) {
std::size_t gt = a.find('>', lt);
ppi_ = std::string(a.substr(lt + 1, gt - lt - 1));
ctx_.ppi = ppi_;
break;
}
}
// default public identity for self-targeted requests (reg-event
// SUBSCRIBE): first sip: P-Associated-URI entry, else the tel: one
// (the temporary IMPU is barred for anything but REGISTER)
for (auto a : imsd::sip::Headers(okMsg, "P-Associated-URI")) {
std::size_t lt = a.find("<sip:");
if (lt != std::string_view::npos) {
std::size_t gt = a.find('>', lt);
ctx_.aor = std::string(a.substr(lt + 1, gt - lt - 1));
break;
}
}
if (ctx_.aor.empty() && !ppi_.empty()) ctx_.aor = ppi_;
if (ppi_.empty()) Log("200: no tel: P-Associated-URI — P-Preferred-Identity omitted");
Log(std::format("self AOR: {}", ctx_.aor.empty() ? ctx_.id.impu : ctx_.aor));
}
// USIM AKA via qmicli UIM logical channel.
std::optional<imsd::aka::AkaResult> Authenticate(std::span<const std::uint8_t> rand16, std::span<const std::uint8_t> autn16) {
auto open = RunCapture({"qmicli", "-d", "qrtr://0",
std::format("--uim-open-logical-channel={},{}", reg_.slot, reg_.aid)});
auto ch = CompletedInt(open.out);
if (!ch) return std::nullopt;
int channel = static_cast<int>(*ch);
auto closeCh = [&] {
RunCapture({"qmicli", "-d", "qrtr://0",
std::format("--uim-close-logical-channel={},{}", reg_.slot, channel)});
};
std::string apdu = imsd::aka::BuildAkaApdu(channel, rand16, autn16);
auto r1 = RunCapture({"qmicli", "-d", "qrtr://0",
std::format("--uim-send-apdu={},{},{}", reg_.slot, channel, apdu)});
auto b1 = CompletedHex(r1.out);
if (!b1) { closeCh(); return std::nullopt; }
if (b1->size() >= 2 && b1->substr(0, 2) == "61") {
std::string gr = imsd::aka::BuildGetResponseApdu(channel, std::stoi(b1->substr(2, 2), nullptr, 16));
auto r2 = RunCapture({"qmicli", "-d", "qrtr://0",
std::format("--uim-send-apdu={},{},{}", reg_.slot, channel, gr)});
b1 = CompletedHex(r2.out);
if (!b1) { closeCh(); return std::nullopt; }
}
closeCh();
auto bytes = imsd::util::FromHex(*b1);
if (!bytes) return std::nullopt;
return imsd::aka::ParseAkaResponse(*bytes);
}
// ---- keepalive refresh (only while idle) ------------------------------
void MaybeRefresh() {
if (call_ || reg_.callid.empty()) return;
if (!sip_.Alive()) return; // MaybeReconnect owns dead-flow recovery
long exp = reg_.expiry ? reg_.expiry : 3600;
double interval;
if (const char* o = std::getenv("REFRESH_INTERVAL")) interval = std::atof(o);
else interval = std::max(120.0, std::min(exp * 0.5, 1800.0));
if (Mono() - lastRefresh_ < interval) return;
try {
RefreshPani();
auto [msg, used] = Reregister(reg_.callid, reg_.ftag, reg_.cseq + 1, reg_.spiUc, reg_.spiUs);
reg_.cseq = used;
if (auto e = imsd::sip::GrantedExpires(msg)) reg_.expiry = *e;
PersistState(reg_, route_, ppi_);
Log(std::format("keepalive re-REGISTER ok (cseq {})", used));
SubscribeRegEvent();
if (!registered_) { registered_ = true; EmitStatus(true); }
else EmitStatus(false);
} catch (const std::exception& e) {
// Whatever failed (dead flow, silent P-CSCF, error status), the
// recovery is the same as a daemon restart: drop the flow and
// let MaybeReconnect re-run the connect + true-refresh sequence.
Log(std::format("keepalive re-REGISTER failed: {}", e.what()));
sip_.Close();
}
lastRefresh_ = Mono();
lastKa_ = Mono();
}
// The protected client flow can die under us while the SA and the
// registration stay valid — a CSFB excursion resets it, the P-CSCF drops
// idle flows — which is exactly the state a daemon restart resumes from
// (s51: "restart-to-recover"). Do what the restart does, in place:
// reconnect the TCP leg over the existing SA and true-refresh. Backoff
// doubles 5 s → 5 min so a dead PDN doesn't turn this into a hot loop.
void MaybeReconnect() {
if (call_ || sip_.Alive() || portPs_ == 0 || reg_.callid.empty()) return;
if (Mono() < nextReconnect_) return;
Log("client flow dead; reconnecting");
sip_.Close();
bool ok = sip_.Connect(local_, PortUc, pcscf_, portPs_, /*tries=*/2);
if (ok) {
try {
RefreshPani();
auto [msg, used] = Reregister(reg_.callid, reg_.ftag, reg_.cseq + 1, reg_.spiUc, reg_.spiUs);
reg_.cseq = used;
if (auto e = imsd::sip::GrantedExpires(msg)) reg_.expiry = *e;
UpdateRouteAndPpi(msg);
LogBindings(msg);
PersistState(reg_, route_, ppi_);
Log("reconnected + re-registered");
SubscribeRegEvent();
if (!registered_) { registered_ = true; EmitStatus(true); }
else EmitStatus(false);
lastRefresh_ = Mono(); lastKa_ = Mono();
reconnectDelay_ = 5;
nextReconnect_ = 0;
return;
} catch (const std::exception& e) {
Log(std::format("reconnect re-REGISTER failed: {}", e.what()));
sip_.Close();
}
}
if (registered_) { registered_ = false; EmitStatus(true); }
nextReconnect_ = Mono() + reconnectDelay_;
reconnectDelay_ = std::min(reconnectDelay_ * 2, 300.0);
}
// (Re-)subscribe to the reg event package (TS 24.229 5.1.1.3): a fresh
// dialog each time, sent over the registration flow; the S-CSCF's
// immediate NOTIFY (logged in DispatchRequest) is the network's own view
// of our bindings. Failure is non-fatal — registration is unaffected.
void SubscribeRegEvent() {
subCallid_ = std::format("{}@{}", rng_.Token(16), local_);
std::string sub = imsd::msg::BuildSubscribeReg(ctx_, subCallid_, rng_.Token(8), rng_.Token(16));
if (sip_.Send(sub)) Log("reg-event SUBSCRIBE sent");
else { Log("reg-event SUBSCRIBE send failed"); subCallid_.clear(); }
}
// ---- command handling -------------------------------------------------
void HandleCmd(const Cmd& c) {
if (c.kind == Cmd::Kind::Stop) { quit_.store(true); return; }
if (c.kind == Cmd::Kind::Dial) {
if (call_) {
Log(std::format("dial({}) refused: call in progress", c.number));
CallInfo bad{c.uni, c.number, "terminated", "error", NowEpoch(), 0};
PostAdded(bad);
PostState(c.uni, "terminated", "error");
PostDeleted(c.uni);
return;
}
// a dead client flow fails the INVITE instantly — give the
// reconnect path one immediate shot first (user action beats
// the backoff timer)
if (!sip_.Alive()) { nextReconnect_ = 0; MaybeReconnect(); }
RefreshPani();
call_.emplace(ctx_, rng_, c.uni, c.number, rtpPort_, precond_);
CallInfo info{c.uni, c.number, "dialing", "outgoing", NowEpoch(), 0};
PostAdded(info);
bool ok = Execute(call_->Start());
if (!ok && call_ && !call_->Terminated()) { Execute(call_->Fail("error")); }
MaybeDropCall();
} else if (c.kind == Cmd::Kind::HangUp) {
if (call_ && call_->Uni() == c.uni) { Execute(call_->OnHangup()); MaybeDropCall(); }
} else if (c.kind == Cmd::Kind::Accept) {
if (call_ && call_->Uni() == c.uni) { Execute(call_->OnAccept()); MaybeDropCall(); }
else Log(std::format("Accept({}) ignored: no such ringing call", c.uni));
}
}
void DispatchRequest(const std::string& msg) {
std::string callid(imsd::sip::Header(msg, "Call-ID").value_or(""));
std::size_t sp = msg.find(' ');
std::string method = msg.substr(0, sp == std::string::npos ? 0 : sp);
if (call_ && callid == call_->CallId()) {
callReply_ = reply_; // freshest channel for this dialog
Execute(call_->OnRequest(msg));
MaybeDropCall();
return;
}
// ACK is never answered — e.g. the caller ACKing the 486/487 of a
// call machine we already dropped
if (method == "ACK") return;
// reg-event NOTIFY: log the S-CSCF's reginfo (every binding it holds
// for the implicit set, feature tags as stored), then 200 it below.
// MESSAGE (terminating SMS-over-IP while +g.3gpp.smsip is
// advertised): log the whole body — the 200 acks delivery, so the
// journal is the only place the payload survives until real SMSoIP
// handling exists.
if (method == "NOTIFY" || method == "MESSAGE") {
std::size_t at = msg.find("\r\n\r\n");
std::string_view body = at == std::string::npos
? std::string_view{}
: std::string_view(msg).substr(at + 4);
if (method == "MESSAGE") Log(std::format("MESSAGE from {} ({} bytes):\n{}", imsd::sip::CallerId(msg), body.size(), body));
else if (auto ev = imsd::sip::Header(msg, "Event"); ev && ev->starts_with("reg")) Log(std::format("reg-event NOTIFY ({} bytes):\n{}", body.size(), body));
if (reply_) reply_(imsd::msg::BuildResponse200(ctx_, msg));
return;
}
if (method == "INVITE") {
OnIncomingInvite(msg);
return;
}
if (reply_)
reply_(imsd::msg::BuildResponse200(ctx_, msg)); // unsolicited (OPTIONS etc.)
}
// An out-of-dialog INVITE: a terminating (incoming) call.
void OnIncomingInvite(const std::string& msg) {
if (call_) {
Log("incoming INVITE while a call exists: 486");
if (reply_) reply_(imsd::msg::BuildInviteResponse(ctx_, msg, 486, "Busy Here", rng_.Token(10)));
return;
}
std::string uni = std::format("ims-call-{}", ++callSeq_);
DumpRaw("imsd-invite-in.raw", msg);
call_.emplace(ctx_, rng_, uni, imsd::engine::IncomingInvite{msg}, rtpPort_);
callReply_ = reply_;
Log(std::format("incoming call {} from {}", uni, call_->Number()));
CallInfo info{uni, call_->Number(), "incoming", "incoming", NowEpoch(), 0,
"incoming"};
PostAdded(info);
Execute(call_->OnInvite());
MaybeDropCall();
}
// ---- action execution -------------------------------------------------
// Returns false if a client-flow send failed (used to fail a dial's INVITE).
bool Execute(const std::vector<imsd::engine::Action>& actions) {
using T = imsd::engine::Action::Type;
bool sendOk = true;
for (const auto& a : actions) {
switch (a.type) {
case T::SendClient:
if (!sip_.Send(a.text)) { sendOk = false; Log("client send failed"); }
break;
case T::SendResponse:
if (callReply_) callReply_(a.text);
else if (reply_) reply_(a.text);
break;
case T::StartMedia: StartMedia(a.media); break;
case T::StopMedia: StopMedia(); break;
case T::State: PostState(call_->Uni(), a.state, a.reason); break;
case T::Deleted: PostDeleted(call_->Uni()); dropCall_ = true; break;
case T::SetDeadline: deadline_ = Mono() + a.seconds; break;
case T::Log: Log(a.text); break;
}
}
return sendOk;
}
void MaybeDropCall() {
if (dropCall_) { call_.reset(); callReply_ = nullptr; dropCall_ = false; }
}
void StartMedia(const imsd::engine::MediaLeg& leg) {
if (!leg.Valid()) { Log("SDP answer missing media endpoint; no media leg"); return; }
Log(std::format("media {} pt={} octet={} -> [{}]:{}", leg.codec, leg.payloadType, leg.octetAlign, leg.remoteIp, leg.remotePort));
if (Is6(leg.remoteIp)) RunCmd({"ip", "-6", "route", "replace", leg.remoteIp, "dev", dev_});
else
RunCmd({"ip", "route", "replace", leg.remoteIp, "dev", dev_});
std::string outBase = std::format("{}/dialer_{}", outDir_, call_ ? call_->Uni() : std::string("x"));
std::vector<std::string> argv = {
mediaBin_, local_, std::to_string(rtpPort_), leg.remoteIp,
std::to_string(leg.remotePort), std::to_string(leg.payloadType),
"86400", outBase};
pid_t pid = fork();
if (pid == 0) {
setenv("MIC", EnvOr("MIC", "1").c_str(), 1);
setenv("PLAY", EnvOr("PLAY", "1").c_str(), 1);
setenv("GAIN", EnvOr("GAIN", "10").c_str(), 1);
setenv("PLAY_GAIN", EnvOr("PLAY_GAIN", "1.0").c_str(), 1);
setenv("AMR_MODE", EnvOr("AMR_MODE", "2").c_str(), 1);
setenv("DTX", EnvOr("DTX", "0").c_str(), 1);
setenv("OCTET_ALIGN", leg.octetAlign ? "1" : "0", 1);
std::vector<char*> c;
for (auto& s : argv) c.push_back(const_cast<char*>(s.c_str()));
c.push_back(nullptr);
execvp(c[0], c.data());
_exit(127);
}
mediaPid_ = pid;
}
void StopMedia() {
if (mediaPid_ <= 0) return;
kill(mediaPid_, SIGTERM);
for (int i = 0; i < 100; i++) {
if (waitpid(mediaPid_, nullptr, WNOHANG) != 0) { mediaPid_ = -1; return; }
usleep(100000);
}
kill(mediaPid_, SIGKILL);
waitpid(mediaPid_, nullptr, 0);
mediaPid_ = -1;
}
void ReapMedia() {
if (!call_ || mediaPid_ <= 0) return;
if (call_->State() != imsd::engine::CallState::Active) return;
int status = 0;
pid_t r = waitpid(mediaPid_, &status, WNOHANG);
if (r == 0) return; // still running
int code = WIFEXITED(status) ? WEXITSTATUS(status) : -1;
mediaPid_ = -1; // reaped; don't re-terminate
Execute(call_->OnMediaExit(code));
MaybeDropCall();
}
// ---- events -----------------------------------------------------------
void EmitStatus(bool registrationSignal) {
auto ev = std::make_unique<Event>();
ev->type = registrationSignal ? Event::Type::Registration : Event::Type::Status;
ev->status = StatusSnapshot{registered_, local_, pcscf_, ppi_, reg_.expiry, reg_.cseq};
PostEvent(std::move(ev));
}
void PostAdded(const CallInfo& info) {
auto ev = std::make_unique<Event>(); ev->type = Event::Type::Added; ev->info = info;
PostEvent(std::move(ev));
}
void PostState(const std::string& uni, const std::string& state, const std::string& reason) {
auto ev = std::make_unique<Event>(); ev->type = Event::Type::State;
ev->uni = uni; ev->state = state; ev->reason = reason;
PostEvent(std::move(ev));
}
void PostDeleted(const std::string& uni) {
auto ev = std::make_unique<Event>(); ev->type = Event::Type::Deleted; ev->uni = uni;
PostEvent(std::move(ev));
}
};
Engine* TheEngine = nullptr;
// ================= GDBus ===================================================
constexpr const char* IntrospectionXml = R"xml(
<node>
<interface name="net.catcrafts.IMS1">
<method name="Dial">
<arg type="s" name="number" direction="in"/>
<arg type="s" name="callUni" direction="out"/>
</method>
<method name="HangUp"><arg type="s" name="callUni" direction="in"/></method>
<method name="Accept"><arg type="s" name="callUni" direction="in"/></method>
<method name="SendDtmf">
<arg type="s" name="callUni" direction="in"/>
<arg type="s" name="tones" direction="in"/>
</method>
<method name="GetCalls"><arg type="aa{sv}" name="calls" direction="out"/></method>
<method name="GetStatus"><arg type="a{sv}" name="status" direction="out"/></method>
<signal name="CallAdded"><arg type="s" name="callUni"/><arg type="a{sv}" name="info"/></signal>
<signal name="CallStateChanged">
<arg type="s" name="callUni"/><arg type="s" name="state"/><arg type="s" name="reason"/>
</signal>
<signal name="CallDeleted"><arg type="s" name="callUni"/></signal>
<signal name="RegistrationChanged"><arg type="b" name="registered"/></signal>
</interface>
</node>)xml";
void HandleMethodCall(GDBusConnection*, const gchar*, const gchar*, const gchar*, const gchar* method, GVariant* params, GDBusMethodInvocation* inv, gpointer) {
std::string_view m = method;
if (m == "Dial") {
const gchar* number = nullptr;
g_variant_get(params, "(&s)", &number);
std::string uni = TheEngine->Dial(number ? number : "");
g_dbus_method_invocation_return_value(inv, g_variant_new("(s)", uni.c_str()));
return;
}
if (m == "HangUp") {
const gchar* uni = nullptr;
g_variant_get(params, "(&s)", &uni);
TheEngine->HangUp(uni ? uni : "");
g_dbus_method_invocation_return_value(inv, nullptr);
return;
}
if (m == "Accept") {
const gchar* uni = nullptr;
g_variant_get(params, "(&s)", &uni);
TheEngine->Accept(uni ? uni : "");
g_dbus_method_invocation_return_value(inv, nullptr);
return;
}
if (m == "SendDtmf") {
Log("SendDtmf accepted but not yet sent (TODO RFC4733)");
g_dbus_method_invocation_return_value(inv, nullptr);
return;
}
if (m == "GetCalls") {
GVariantBuilder b;
g_variant_builder_init(&b, G_VARIANT_TYPE("aa{sv}"));
for (auto& [uni, info] : Calls)
g_variant_builder_add_value(&b, CallVariant(info));
g_dbus_method_invocation_return_value(inv, g_variant_new("(aa{sv})", &b));
return;
}
if (m == "GetStatus") {
GVariantBuilder b;
g_variant_builder_init(&b, G_VARIANT_TYPE("a{sv}"));
g_variant_builder_add(&b, "{sv}", "registered", g_variant_new_boolean(StatusSnap.registered));
g_variant_builder_add(&b, "{sv}", "local", g_variant_new_string(StatusSnap.local.c_str()));
g_variant_builder_add(&b, "{sv}", "pcscf", g_variant_new_string(StatusSnap.pcscf.c_str()));
g_variant_builder_add(&b, "{sv}", "expiry", g_variant_new_int64(StatusSnap.expiry));
g_variant_builder_add(&b, "{sv}", "cseq", g_variant_new_int64(StatusSnap.cseq));
g_variant_builder_add(&b, "{sv}", "ppi", g_variant_new_string(StatusSnap.ppi.c_str()));
g_dbus_method_invocation_return_value(inv, g_variant_new("(a{sv})", &b));
return;
}
g_dbus_method_invocation_return_dbus_error(inv, "org.freedesktop.DBus.Error.UnknownMethod", "no such method");
}
const GDBusInterfaceVTable Vtable = { HandleMethodCall, nullptr, nullptr, {} };
void OnBusAcquired(GDBusConnection* conn, const gchar*, gpointer) {
DbusConn = conn;
GDBusNodeInfo* node = g_dbus_node_info_new_for_xml(IntrospectionXml, nullptr);
g_dbus_connection_register_object(conn, ObjPath, node->interfaces[0], &Vtable, nullptr, nullptr, nullptr);
g_dbus_node_info_unref(node);
Log(std::format("object registered at {}", ObjPath));
}
gboolean OnTerm(gpointer loop) {
Log("SIGTERM — stopping engine (SA kept)");
if (TheEngine) TheEngine->Stop();
g_timeout_add_seconds(2, [](gpointer l) -> gboolean {
g_main_loop_quit(static_cast<GMainLoop*>(l)); return G_SOURCE_REMOVE; }, loop);
return G_SOURCE_REMOVE;
}
} // namespace
int main(int argc, char** argv) {
bool session = false;
for (int i = 1; i < argc; i++)
if (std::string_view(argv[i]) == "--session") session = true;
if (argv[0]) {
std::string p = argv[0];
auto slash = p.find_last_of('/');
if (slash != std::string::npos) SelfDir = p.substr(0, slash);
}
if (!session && geteuid() != 0) {
std::println(std::cerr, "imsd: must run as root (xfrm / qmicli)");
return 1;
}
std::string dev = EnvOr("DEV", "qmapmux0.0");
std::string local = EnvOr("LOCAL", "");
if (local.empty()) {
if (auto l = DetectLocal(dev)) local = *l;
}
if (local.empty() && !session) {
std::println(std::cerr, "imsd: no global IPv6 on {} — is the ims PDN up?", dev);
return 1;
}
Log(std::format("LOCAL={} P-CSCF=[{}]:{}", local, EnvOr("PCSCF", "(unset)"), EnvOr("PCSCF_PORT", "5060")));
Engine engine;
engine.SetLocal(local);
engine.SetDevMode(session);
TheEngine = &engine;
MainLoop = g_main_loop_new(nullptr, FALSE);
guint owner = g_bus_own_name(
session ? G_BUS_TYPE_SESSION : G_BUS_TYPE_SYSTEM, BusName,
G_BUS_NAME_OWNER_FLAGS_NONE, OnBusAcquired,
[](GDBusConnection*, const gchar* name, gpointer) { Log(std::format("owning {}", name)); },
[](GDBusConnection*, const gchar* name, gpointer lp) {
Log(std::format("lost {} — exiting", name));
g_main_loop_quit(static_cast<GMainLoop*>(lp));
},
MainLoop, nullptr);
g_unix_signal_add(SIGTERM, OnTerm, MainLoop);
g_unix_signal_add(SIGINT, OnTerm, MainLoop);
// Run the engine on a pthread with an explicit 8 MiB stack: musl's default
// thread stack is only 128 KiB, and the registration paths hold 64 KiB SIP
// recv buffers on the stack (a std::thread here segfaults on entry). The
// registration is bus-independent, so start it immediately.
pthread_t engineTid{};
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setstacksize(&attr, 8 * 1024 * 1024);
pthread_create(&engineTid, &attr, [](void*) -> void* { TheEngine->Run(); return nullptr; }, nullptr);
pthread_attr_destroy(&attr);
Log(std::format("starting on the {} bus", session ? "session" : "system"));
g_main_loop_run(MainLoop);
engine.Stop();
pthread_join(engineTid, nullptr);
g_bus_unown_name(owner);
g_main_loop_unref(MainLoop);
return 0;
}