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>
This commit is contained in:
commit
6e77823933
31 changed files with 8761 additions and 0 deletions
236
interfaces/Imsd-Sip.cppm
Normal file
236
interfaces/Imsd-Sip.cppm
Normal file
|
|
@ -0,0 +1,236 @@
|
|||
// SPDX-License-Identifier: GPL-3.0-only
|
||||
// SPDX-FileCopyrightText: Copyright (C) 2026 Catcrafts®
|
||||
|
||||
// lint-disable-file fixed-width-types
|
||||
/*
|
||||
Imsd:Sip — SIP message text layer + TCP framing.
|
||||
|
||||
Deliberately a text layer, not a full RFC 3261 parser: the engine works on
|
||||
whole messages as strings and pulls out exactly what it needs (headers,
|
||||
status codes, the granted registration lifetime), which keeps every message
|
||||
loggable and testable verbatim. Edge-case behavior (empty header values,
|
||||
line anchoring, keepalive discards) is pinned by tests/Sip — a change that
|
||||
flips one of those tests is a behavior change, not a cleanup.
|
||||
|
||||
Pure std C++ (no GLib).
|
||||
*/
|
||||
|
||||
export module Imsd:Sip;
|
||||
import std;
|
||||
|
||||
namespace imsd::sip {
|
||||
|
||||
constexpr char AsciiLower(char c) {
|
||||
return (c >= 'A' && c <= 'Z') ? static_cast<char>(c - 'A' + 'a') : c;
|
||||
}
|
||||
|
||||
constexpr bool IEqualsPrefix(std::string_view text, std::string_view prefix) {
|
||||
if (text.size() < prefix.size()) return false;
|
||||
for (std::size_t i = 0; i < prefix.size(); i++)
|
||||
if (AsciiLower(text[i]) != AsciiLower(prefix[i])) return false;
|
||||
return true;
|
||||
}
|
||||
|
||||
// spaces, tabs, CR, LF off both ends
|
||||
constexpr std::string_view Trim(std::string_view s) {
|
||||
while (!s.empty() && (s.front() == ' ' || s.front() == '\t' || s.front() == '\r' || s.front() == '\n'))
|
||||
s.remove_prefix(1);
|
||||
while (!s.empty() && (s.back() == ' ' || s.back() == '\t' || s.back() == '\r' || s.back() == '\n'))
|
||||
s.remove_suffix(1);
|
||||
return s;
|
||||
}
|
||||
|
||||
// Iterate \n-separated lines (any trailing CR stays on the line and is
|
||||
// stripped by Trim when a value is extracted).
|
||||
template <typename F>
|
||||
void ForEachLine(std::string_view msg, F&& f) {
|
||||
std::size_t pos = 0;
|
||||
while (pos <= msg.size()) {
|
||||
std::size_t nl = msg.find('\n', pos);
|
||||
std::string_view line = msg.substr(pos, nl == std::string_view::npos ? std::string_view::npos : nl - pos);
|
||||
if (!f(line)) return;
|
||||
if (nl == std::string_view::npos) return;
|
||||
pos = nl + 1;
|
||||
}
|
||||
}
|
||||
|
||||
// One "Name: value" match: name anchored at line start (case-insensitive,
|
||||
// per RFC 3261 header names), immediately followed by the colon — no
|
||||
// whitespace before it — and at least one character (even just the CR)
|
||||
// after it. A bare "Name:\r" line matches with value ""; a "Name:" that
|
||||
// ends the buffer does not match. Matching never crosses the line
|
||||
// boundary: an empty-valued header yields "", NOT the next line's
|
||||
// content (a regex-based implementation whose whitespace class eats the
|
||||
// CRLF gets that wrong — pinned by the "bare header" test).
|
||||
std::optional<std::string_view> MatchHeaderLine(std::string_view line, std::string_view name) {
|
||||
if (!IEqualsPrefix(line, name)) return std::nullopt;
|
||||
if (line.size() <= name.size() || line[name.size()] != ':') return std::nullopt;
|
||||
std::string_view rest = line.substr(name.size() + 1);
|
||||
if (rest.empty()) return std::nullopt;
|
||||
return Trim(rest);
|
||||
}
|
||||
|
||||
// First run of ASCII digits starting at `s`; nullopt if none.
|
||||
std::optional<long> LeadingDigits(std::string_view s) {
|
||||
std::size_t n = 0;
|
||||
while (n < s.size() && s[n] >= '0' && s[n] <= '9')
|
||||
n++;
|
||||
if (n == 0) return std::nullopt;
|
||||
long v = 0;
|
||||
auto [_, ec] = std::from_chars(s.data(), s.data() + n, v);
|
||||
if (ec != std::errc{}) return std::nullopt;
|
||||
return v;
|
||||
}
|
||||
}
|
||||
|
||||
export namespace imsd::sip {
|
||||
|
||||
// Value of the first `name:` header, trimmed; nullopt if absent.
|
||||
std::optional<std::string_view> Header(std::string_view msg, std::string_view name) {
|
||||
std::optional<std::string_view> out;
|
||||
ForEachLine(msg, [&](std::string_view line) {
|
||||
if (auto v = MatchHeaderLine(line, name)) {
|
||||
out = *v;
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
});
|
||||
return out;
|
||||
}
|
||||
|
||||
// Every `name:` header value, in order.
|
||||
std::vector<std::string_view> Headers(std::string_view msg, std::string_view name) {
|
||||
std::vector<std::string_view> out;
|
||||
ForEachLine(msg, [&](std::string_view line) {
|
||||
if (auto v = MatchHeaderLine(line, name)) out.push_back(*v);
|
||||
return true;
|
||||
});
|
||||
return out;
|
||||
}
|
||||
|
||||
// The 3-digit code of a "SIP/2.0 NNN ..." response start-line; nullopt
|
||||
// for requests / anything else. Only matches at the start of the message.
|
||||
std::optional<int> Status(std::string_view msg) {
|
||||
constexpr std::string_view Prefix = "SIP/2.0 ";
|
||||
if (!msg.starts_with(Prefix) || msg.size() < Prefix.size() + 3) return std::nullopt;
|
||||
std::string_view d = msg.substr(Prefix.size(), 3);
|
||||
for (char c : d)
|
||||
if (c < '0' || c > '9') return std::nullopt;
|
||||
int v = 0;
|
||||
std::from_chars(d.data(), d.data() + 3, v);
|
||||
return v;
|
||||
}
|
||||
|
||||
// Where a UDP response to this request must go (RFC 3261 18.2.2): the
|
||||
// top Via's sent-by port — unless the Via carries rport, in which case
|
||||
// the caller should reply to the request's source port instead
|
||||
// (nullopt). Also nullopt when the Via has no explicit port (5060 is
|
||||
// the default, but our P-CSCF flows always carry one). Handles
|
||||
// "[v6]:port" and "host:port" sent-by forms.
|
||||
std::optional<int> ViaResponsePort(std::string_view msg) {
|
||||
auto via = Header(msg, "Via");
|
||||
if (!via) return std::nullopt;
|
||||
std::string_view v = *via;
|
||||
if (std::size_t sc = v.find(';'); sc != std::string_view::npos) {
|
||||
if (v.substr(sc).find("rport") != std::string_view::npos) return std::nullopt;
|
||||
v = v.substr(0, sc);
|
||||
}
|
||||
std::size_t colon;
|
||||
if (std::size_t br = v.rfind(']'); br != std::string_view::npos)
|
||||
colon = v.find(':', br); // v6: port only after the ]
|
||||
else
|
||||
colon = v.rfind(':'); // v4/hostname (transport token
|
||||
// has no colon of its own)
|
||||
if (colon == std::string_view::npos) return std::nullopt;
|
||||
if (auto p = LeadingDigits(Trim(v.substr(colon + 1))))
|
||||
if (*p > 0 && *p < 65536) return static_cast<int>(*p);
|
||||
return std::nullopt;
|
||||
}
|
||||
|
||||
// Registration lifetime granted by a REGISTER 200 OK: the Contact
|
||||
// header's expires= parameter (the registrar's answer for our binding),
|
||||
// else the Expires header; nullopt if absent. "expires=" is searched
|
||||
// anywhere in each Contact value, not parameter-parsed.
|
||||
std::optional<long> GrantedExpires(std::string_view msg) {
|
||||
for (std::string_view contact : Headers(msg, "Contact")) {
|
||||
std::size_t at = contact.find("expires=");
|
||||
if (at != std::string_view::npos)
|
||||
if (auto v = LeadingDigits(contact.substr(at + 8))) return v;
|
||||
}
|
||||
if (auto e = Header(msg, "Expires")) {
|
||||
std::string_view v = *e;
|
||||
if (!v.empty() && v.find_first_not_of("0123456789") == std::string_view::npos) return LeadingDigits(v);
|
||||
}
|
||||
return std::nullopt;
|
||||
}
|
||||
|
||||
// Caller identity of an inbound request: the number/user of the first
|
||||
// P-Asserted-Identity (the network-asserted identity, RFC 3325), falling
|
||||
// back to From. Understands "<tel:+31612345678>", "<sip:+31612345678@
|
||||
// host;user=phone>" (user part) and bare values; returns "" if neither
|
||||
// header yields one. Anonymous callers come out as "anonymous".
|
||||
std::string CallerId(std::string_view msg) {
|
||||
auto extract = [](std::string_view v) -> std::optional<std::string> {
|
||||
std::string_view uri = v;
|
||||
std::size_t lt = v.find('<');
|
||||
if (lt != std::string_view::npos) {
|
||||
std::size_t gt = v.find('>', lt);
|
||||
if (gt != std::string_view::npos) uri = v.substr(lt + 1, gt - lt - 1);
|
||||
} else {
|
||||
std::size_t semi = v.find(';');
|
||||
if (semi != std::string_view::npos) uri = v.substr(0, semi);
|
||||
uri = Trim(uri);
|
||||
}
|
||||
if (uri.starts_with("tel:")) {
|
||||
std::string_view n = uri.substr(4);
|
||||
std::size_t semi = n.find(';');
|
||||
if (semi != std::string_view::npos) n = n.substr(0, semi);
|
||||
return std::string(n);
|
||||
}
|
||||
if (uri.starts_with("sip:") || uri.starts_with("sips:")) {
|
||||
std::string_view n = uri.substr(uri.find(':') + 1);
|
||||
std::size_t end = n.find_first_of("@;");
|
||||
if (end == std::string_view::npos) return std::nullopt;
|
||||
return std::string(n.substr(0, end));
|
||||
}
|
||||
return std::nullopt;
|
||||
};
|
||||
for (std::string_view h : Headers(msg, "P-Asserted-Identity"))
|
||||
if (auto n = extract(h)) return *n;
|
||||
if (auto f = Header(msg, "From"))
|
||||
if (auto n = extract(*f)) return *n;
|
||||
return "";
|
||||
}
|
||||
|
||||
// SIP-over-TCP stream framing, transport-free: feed received bytes into
|
||||
// Append(), pull complete messages (headers + Content-Length body) out
|
||||
// of TryExtract(). Leading CRLFs (RFC 5626 keepalive pongs) are
|
||||
// discarded.
|
||||
class FrameBuffer {
|
||||
public:
|
||||
void Append(std::string_view data) { buf_.append(data); }
|
||||
|
||||
// One complete SIP message off the front of the buffer, or nullopt
|
||||
// if more bytes are needed. Content-Length is located with the same
|
||||
// line-anchored matching rules as Header().
|
||||
std::optional<std::string> TryExtract() {
|
||||
std::size_t keep = buf_.find_first_not_of("\r\n");
|
||||
buf_.erase(0, keep == std::string::npos ? buf_.size() : keep);
|
||||
std::size_t idx = buf_.find("\r\n\r\n");
|
||||
if (idx == std::string::npos) return std::nullopt;
|
||||
std::string_view head = std::string_view(buf_).substr(0, idx);
|
||||
long clen = 0;
|
||||
if (auto v = Header(head, "Content-Length")) clen = LeadingDigits(*v).value_or(0);
|
||||
std::size_t total = idx + 4 + static_cast<std::size_t>(clen);
|
||||
if (buf_.size() < total) return std::nullopt;
|
||||
std::string msg = buf_.substr(0, total);
|
||||
buf_.erase(0, total);
|
||||
return msg;
|
||||
}
|
||||
|
||||
std::size_t Size() const { return buf_.size(); }
|
||||
|
||||
private:
|
||||
std::string buf_;
|
||||
};
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue