//! Synchronous 9P2000 session over a blocking file descriptor. //! //! A thin RPC layer over `cloud9.Client` (push/take, allocation-free). One request //! is outstanding at a time: the FUSE loop that drives this is single-threaded, so //! every call here blocks until its reply (or the connection's death) arrives. //! Fids are handed out from a free list; fid 0 is reserved for the root. const std = @import("std"); const cloud9 = @import("cloud9"); const linux = std.os.linux; pub const Address = union(enum) { unix: []const u8, tcp: struct { host: []const u8, port: u16 }, fd: i32, }; /// A Stat whose every field means "leave unchanged" in a Twstat. pub const dontcare = cloud9.Stat{ .type = 0xFFFF, .dev = 0xFFFF_FFFF, .qid = .{ .type = 0xFF, .version = 0xFFFF_FFFF, .path = 0xFFFF_FFFF_FFFF_FFFF }, .mode = 0xFFFF_FFFF, .atime = 0xFFFF_FFFF, .mtime = 0xFFFF_FFFF, .length = 0xFFFF_FFFF_FFFF_FFFF, .name = "", .uid = "", .gid = "", .muid = "", }; pub const Session = struct { pub const Error = error{ Nine, Protocol, Io, Closed, Stopped, TooLarge, OutOfMemory }; pub const Walk = struct { nwqid: u16, wqid: [cloud9.max_welem]cloud9.Qid }; pub const Open = struct { qid: cloud9.Qid, iounit: u32 }; gpa: std.mem.Allocator, fd: i32, client: cloud9.Client, in_buf: []u8, out_buf: []u8, /// After `error.Nine`, the server's Rerror text (copied, bounded). ename: [256]u8 = undefined, ename_len: usize = 0, /// Negotiated maximum message size. msize: u32, next_fid: u32 = 1, free_fids: std.ArrayList(u32) = .empty, /// Per-fid iounit learned from open/create (0 = none); used to chunk read/write. iounits: std.AutoHashMapUnmanaged(u32, u32) = .empty, /// Optional descriptor watched while waiting for a reply: when it becomes /// readable (the bridge's "child exited" pipe) the pending rpc fails with /// `error.Stopped` instead of blocking on a server that never answers. stop_fd: i32 = -1, /// Connect to `address`, then negotiate the protocol version. /// `msize` is the maximum message size to ask for (0 = the buffers' size). pub fn connect(gpa: std.mem.Allocator, address: Address, msize: u32) !Session { const want: u32 = if (msize == 0) 8192 else @max(msize, 24); const fd = try openTransport(address); errdefer if (address != .fd) { _ = linux.close(fd); }; const in_buf = try gpa.alloc(u8, want); errdefer gpa.free(in_buf); const out_buf = try gpa.alloc(u8, want); errdefer gpa.free(out_buf); var s: Session = .{ .gpa = gpa, .fd = fd, .client = .init(.{ .in = in_buf, .out = out_buf }), .in_buf = in_buf, .out_buf = out_buf, .msize = want, }; const r = try s.rpc(.{ .version = .{ .msize = want } }); if (!std.mem.eql(u8, r.version.version, "9P2000")) return error.Protocol; s.msize = r.version.msize; return s; } /// Closes the descriptor and frees the buffers. Fids are not clunked. pub fn deinit(s: *Session) void { _ = linux.close(s.fd); s.free_fids.deinit(s.gpa); s.iounits.deinit(s.gpa); s.gpa.free(s.in_buf); s.gpa.free(s.out_buf); s.* = undefined; } pub fn attach(s: *Session, fid: u32, uname: []const u8, aname: []const u8) Error!cloud9.Qid { const r = try s.rpc(.{ .attach = .{ .fid = fid, .uname = uname, .aname = aname } }); return r.attach; } /// Fid 0 is never handed out: it belongs to the root attach. pub fn allocFid(s: *Session) u32 { if (s.free_fids.pop()) |fid| return fid; const fid = s.next_fid; s.next_fid += 1; return fid; } /// Fids currently bound (excluding fid 0); a debugging aid for leak hunting. pub fn fidsInUse(s: *const Session) usize { return (s.next_fid - 1) - s.free_fids.items.len; } pub fn freeFid(s: *Session, fid: u32) void { _ = s.iounits.remove(fid); // If the free list cannot grow the fid is simply leaked; the counter keeps going. s.free_fids.append(s.gpa, fid) catch {}; } /// Generic RPC. Result slices borrow the input buffer until the next call. pub fn rpc(s: *Session, req: cloud9.Client.Request) Error!cloud9.Client.Result { s.ename_len = 0; _ = s.client.submit(req) catch |e| switch (e) { error.NoTags, error.Handshake, error.Dead => return error.Protocol, error.NoSpace, error.TooLarge => return error.TooLarge, error.BadRequest => { s.setEname("bad request"); return error.Nine; }, }; try s.flush(); var tmp: [64 * 1024]u8 = undefined; while (true) { if (s.client.take()) |done| { switch (done.result) { .fail => |ename| { s.setEname(ename); return error.Nine; }, else => return done.result, } } if (s.client.dead) return error.Protocol; // After take() returned null the previous frame is gone, so the free // space is at least what the pending frame still needs. const room = s.client.in.len - s.client.in_len; if (room == 0) return error.Protocol; const n = try readSome(s.fd, s.stop_fd, tmp[0..@min(room, tmp.len)]); if (n == 0) return error.Closed; const pushed = s.client.push(tmp[0..n]); if (pushed != n) return error.Protocol; } } /// Walk `names` from `fid` to `newfid`. A partial walk leaves `newfid` unbound /// (9P semantics) and reports `error.Nine` with ename "file does not exist". pub fn walk(s: *Session, fid: u32, newfid: u32, names: []const []const u8) Error!Walk { const r = try s.rpc(.{ .walk = .{ .fid = fid, .newfid = newfid, .names = names } }); if (r.walk.nwqid < names.len) { s.setEname("file does not exist"); return error.Nine; } return .{ .nwqid = r.walk.nwqid, .wqid = r.walk.wqid }; } /// allocFid + zero-element walk. The fid is released again on failure. pub fn clone(s: *Session, fid: u32) Error!u32 { const newfid = s.allocFid(); errdefer s.freeFid(newfid); _ = try s.walk(fid, newfid, &.{}); return newfid; } pub fn open(s: *Session, fid: u32, mode: u8) Error!Open { const r = try s.rpc(.{ .open = .{ .fid = fid, .mode = mode } }); s.noteIounit(fid, r.open.iounit); return .{ .qid = r.open.qid, .iounit = r.open.iounit }; } pub fn create(s: *Session, fid: u32, name: []const u8, perm: u32, mode: u8) Error!Open { const r = try s.rpc(.{ .create = .{ .fid = fid, .name = name, .perm = perm, .mode = mode } }); s.noteIounit(fid, r.create.iounit); return .{ .qid = r.create.qid, .iounit = r.create.iounit }; } /// Reads into `buf`, chunking by min(maxRead, iounit) and stopping at the first /// short read. Returns the number of bytes read (0 at end of file). pub fn read(s: *Session, fid: u32, offset: u64, buf: []u8) Error!usize { return readWith(s, rpc, fid, offset, buf, s.chunk(fid)); } /// Writes `data`, chunking like `read` and stopping at the first short write. pub fn write(s: *Session, fid: u32, offset: u64, data: []const u8) Error!usize { return writeWith(s, rpc, fid, offset, data, s.chunkWrite(fid)); } /// The returned Stat's strings (name/uid/gid/muid) borrow the session's input /// buffer: they are valid only until the next rpc. Copy what must outlive it. pub fn stat(s: *Session, fid: u32) Error!cloud9.Stat { const r = try s.rpc(.{ .stat = .{ .fid = fid } }); return r.stat; } pub fn wstat(s: *Session, fid: u32, st: cloud9.Stat) Error!void { _ = try s.rpc(.{ .wstat = .{ .fid = fid, .stat = st } }); } /// Frees the fid locally even when the server reports an error. pub fn clunk(s: *Session, fid: u32) Error!void { defer s.freeFid(fid); _ = try s.rpc(.{ .clunk = .{ .fid = fid } }); } /// Frees the fid locally even when the server reports an error. pub fn remove(s: *Session, fid: u32) Error!void { defer s.freeFid(fid); _ = try s.rpc(.{ .remove = .{ .fid = fid } }); } /// Maps the last Rerror text to an errno (case-insensitive substring match). pub fn errno(s: *const Session) linux.E { return enameToErrno(s.ename[0..s.ename_len]); } // -- internals -------------------------------------------------------------- fn setEname(s: *Session, text: []const u8) void { const n = @min(text.len, 255); @memcpy(s.ename[0..n], text[0..n]); s.ename_len = n; } fn noteIounit(s: *Session, fid: u32, iounit: u32) void { if (iounit == 0) { _ = s.iounits.remove(fid); } else { s.iounits.put(s.gpa, fid, iounit) catch {}; } } fn chunk(s: *Session, fid: u32) u32 { return chunkSize(s.client.maxRead(), s.iounits.get(fid) orelse 0); } fn chunkWrite(s: *Session, fid: u32) u32 { return chunkSize(s.client.maxWrite(), s.iounits.get(fid) orelse 0); } /// Writes everything in the client's output buffer to the socket. fn flush(s: *Session) Error!void { while (s.client.output().len != 0) { const out = s.client.output(); const rc = linux.write(s.fd, out.ptr, out.len); switch (linux.errno(rc)) { .SUCCESS => { if (rc == 0) return error.Closed; s.client.wrote(rc); }, .INTR, .AGAIN => continue, .PIPE, .CONNRESET => return error.Closed, else => return error.Io, } } } }; fn chunkSize(max: u32, iounit: u32) u32 { if (iounit != 0 and iounit < max) return iounit; return max; } /// Chunked read over any rpc-shaped function (injected so the loop is testable). fn readWith( s: anytype, comptime rpcFn: anytype, fid: u32, offset: u64, buf: []u8, max_chunk: u32, ) Session.Error!usize { if (max_chunk == 0) return error.Protocol; var done: usize = 0; while (done < buf.len) { const want: u32 = @intCast(@min(buf.len - done, max_chunk)); const r = try rpcFn(s, .{ .read = .{ .fid = fid, .offset = offset + done, .count = want } }); const data = r.read; @memcpy(buf[done..][0..data.len], data); done += data.len; if (data.len < want) break; } return done; } /// Chunked write over any rpc-shaped function. fn writeWith( s: anytype, comptime rpcFn: anytype, fid: u32, offset: u64, data: []const u8, max_chunk: u32, ) Session.Error!usize { if (max_chunk == 0) return error.Protocol; var done: usize = 0; while (done < data.len) { const want: usize = @min(data.len - done, max_chunk); const r = try rpcFn(s, .{ .write = .{ .fid = fid, .offset = offset + done, .data = data[done..][0..want] } }); done += r.write; if (r.write < want) break; } return done; } fn readSome(fd: i32, stop_fd: i32, buf: []u8) Session.Error!usize { while (true) { if (stop_fd >= 0) { var pfds = [_]linux.pollfd{ .{ .fd = fd, .events = linux.POLL.IN, .revents = 0 }, .{ .fd = stop_fd, .events = linux.POLL.IN, .revents = 0 }, }; const prc = linux.poll(&pfds, pfds.len, -1); switch (linux.errno(prc)) { .SUCCESS => {}, .INTR, .AGAIN => continue, else => return error.Io, } if (pfds[1].revents != 0 and pfds[0].revents == 0) return error.Stopped; } const rc = linux.read(fd, buf.ptr, buf.len); switch (linux.errno(rc)) { .SUCCESS => return rc, .INTR, .AGAIN => continue, .CONNRESET => return error.Closed, else => return error.Io, } } } /// Rerror text → errno, per docs/DESIGN.md (first match wins). pub fn enameToErrno(ename: []const u8) linux.E { const Rule = struct { needle: []const u8, err: linux.E }; const rules = [_]Rule{ .{ .needle = "not exist", .err = .NOENT }, .{ .needle = "not found", .err = .NOENT }, .{ .needle = "no such", .err = .NOENT }, .{ .needle = "exists", .err = .EXIST }, .{ .needle = "not empty", .err = .NOTEMPTY }, .{ .needle = "not a dir", .err = .NOTDIR }, .{ .needle = "is a dir", .err = .ISDIR }, .{ .needle = "permission", .err = .ACCES }, .{ .needle = "denied", .err = .ACCES }, .{ .needle = "read-only", .err = .ROFS }, .{ .needle = "read only", .err = .ROFS }, .{ .needle = "readonly", .err = .ROFS }, .{ .needle = "no space", .err = .NOSPC }, .{ .needle = "not allowed", .err = .PERM }, .{ .needle = "not permitted", .err = .PERM }, .{ .needle = "cannot", .err = .PERM }, .{ .needle = "fid", .err = .BADF }, .{ .needle = "bad offset", .err = .INVAL }, .{ .needle = "invalid", .err = .INVAL }, .{ .needle = "bad ", .err = .INVAL }, .{ .needle = "busy", .err = .BUSY }, .{ .needle = "in use", .err = .BUSY }, .{ .needle = "too long", .err = .NAMETOOLONG }, .{ .needle = "not supported", .err = .OPNOTSUPP }, .{ .needle = "unsupported", .err = .OPNOTSUPP }, }; for (rules) |rule| { if (std.ascii.findIgnoreCase(ename, rule.needle) != null) return rule.err; } return .IO; } // -- transport ------------------------------------------------------------------ fn openTransport(address: Address) !i32 { switch (address) { .fd => |fd| return fd, .unix => |path| { if (path.len == 0 or path.len >= 108) return error.NameTooLong; var sa: linux.sockaddr.un = .{ .path = @splat(0) }; @memcpy(sa.path[0..path.len], path); const fd = try newSocket(linux.AF.UNIX, 0); errdefer _ = linux.close(fd); try doConnect(fd, @ptrCast(&sa), @sizeOf(linux.sockaddr.un)); return fd; }, .tcp => |t| { const ip = std.Io.net.IpAddress.parse(t.host, t.port) catch return error.InvalidAddress; switch (ip) { .ip4 => |a| { const sa: linux.sockaddr.in = .{ .port = std.mem.nativeToBig(u16, t.port), .addr = @bitCast(a.bytes), }; const fd = try newSocket(linux.AF.INET, linux.IPPROTO.TCP); errdefer _ = linux.close(fd); setNodelay(fd); try doConnect(fd, @ptrCast(&sa), @sizeOf(linux.sockaddr.in)); return fd; }, .ip6 => |a| { const sa: linux.sockaddr.in6 = .{ .port = std.mem.nativeToBig(u16, t.port), .flowinfo = 0, .addr = a.bytes, .scope_id = 0, }; const fd = try newSocket(linux.AF.INET6, linux.IPPROTO.TCP); errdefer _ = linux.close(fd); setNodelay(fd); try doConnect(fd, @ptrCast(&sa), @sizeOf(linux.sockaddr.in6)); return fd; }, } }, } } fn newSocket(domain: u32, protocol: u32) !i32 { const rc = linux.socket(domain, linux.SOCK.STREAM | linux.SOCK.CLOEXEC, protocol); switch (linux.errno(rc)) { .SUCCESS => return @intCast(rc), .MFILE, .NFILE => return error.ProcessFdQuotaExceeded, .AFNOSUPPORT, .PROTONOSUPPORT => return error.AddressFamilyNotSupported, .ACCES => return error.AccessDenied, .NOMEM, .NOBUFS => return error.SystemResources, else => return error.Unexpected, } } fn setNodelay(fd: i32) void { const one: u32 = 1; _ = linux.setsockopt(fd, linux.IPPROTO.TCP, linux.TCP.NODELAY, @ptrCast(&one), @sizeOf(u32)); } fn doConnect(fd: i32, addr: *const linux.sockaddr, len: linux.socklen_t) !void { while (true) { const rc = linux.connect(fd, addr, len); switch (linux.errno(rc)) { .SUCCESS => return, .INTR => continue, .CONNREFUSED => return error.ConnectionRefused, .NOENT, .NOTDIR => return error.FileNotFound, .ACCES, .PERM => return error.AccessDenied, .TIMEDOUT => return error.ConnectionTimedOut, .NETUNREACH, .HOSTUNREACH => return error.NetworkUnreachable, .ADDRNOTAVAIL => return error.AddressNotAvailable, .AGAIN, .INPROGRESS => return error.WouldBlock, else => return error.Unexpected, } } } // -- tests ---------------------------------------------------------------------- const testing = std.testing; test { testing.refAllDecls(@This()); } test "ename → errno mapping" { try testing.expectEqual(linux.E.NOENT, enameToErrno("file does not exist")); try testing.expectEqual(linux.E.NOENT, enameToErrno("No Such File")); try testing.expectEqual(linux.E.NOENT, enameToErrno("directory entry not found")); try testing.expectEqual(linux.E.EXIST, enameToErrno("file already exists")); try testing.expectEqual(linux.E.NOTEMPTY, enameToErrno("directory not empty")); try testing.expectEqual(linux.E.NOTDIR, enameToErrno("not a directory")); try testing.expectEqual(linux.E.ISDIR, enameToErrno("is a directory")); try testing.expectEqual(linux.E.ACCES, enameToErrno("permission denied")); try testing.expectEqual(linux.E.ACCES, enameToErrno("access denied")); try testing.expectEqual(linux.E.ROFS, enameToErrno("read-only file system")); try testing.expectEqual(linux.E.NOSPC, enameToErrno("no space left")); try testing.expectEqual(linux.E.PERM, enameToErrno("operation not permitted")); try testing.expectEqual(linux.E.PERM, enameToErrno("cannot remove root")); try testing.expectEqual(linux.E.BADF, enameToErrno("unknown fid")); try testing.expectEqual(linux.E.BADF, enameToErrno("fid in use")); // "fid" precedes "in use" try testing.expectEqual(linux.E.INVAL, enameToErrno("bad offset")); try testing.expectEqual(linux.E.INVAL, enameToErrno("invalid argument")); try testing.expectEqual(linux.E.INVAL, enameToErrno("bad request")); try testing.expectEqual(linux.E.BUSY, enameToErrno("device busy")); try testing.expectEqual(linux.E.NAMETOOLONG, enameToErrno("name too long")); try testing.expectEqual(linux.E.OPNOTSUPP, enameToErrno("operation not supported")); try testing.expectEqual(linux.E.IO, enameToErrno("something odd happened")); try testing.expectEqual(linux.E.IO, enameToErrno("")); } test "fid allocator recycles and never hands out 0" { var s: Session = undefined; s.gpa = testing.allocator; s.next_fid = 1; s.free_fids = .empty; s.iounits = .empty; defer s.free_fids.deinit(s.gpa); defer s.iounits.deinit(s.gpa); const a = s.allocFid(); const b = s.allocFid(); const c = s.allocFid(); try testing.expectEqual(@as(u32, 1), a); try testing.expectEqual(@as(u32, 2), b); try testing.expectEqual(@as(u32, 3), c); s.freeFid(b); try testing.expectEqual(b, s.allocFid()); s.freeFid(a); s.freeFid(c); const x = s.allocFid(); const y = s.allocFid(); try testing.expect((x == a and y == c) or (x == c and y == a)); try testing.expectEqual(@as(u32, 4), s.allocFid()); try testing.expect(a != 0 and b != 0 and c != 0); } test "chunkSize honours iounit only when smaller" { try testing.expectEqual(@as(u32, 100), chunkSize(100, 0)); try testing.expectEqual(@as(u32, 40), chunkSize(100, 40)); try testing.expectEqual(@as(u32, 100), chunkSize(100, 400)); } /// Fake rpc for the chunked read/write loops: a file of `len` bytes where byte i == i & 0xff. const FakeFile = struct { len: usize, calls: usize = 0, max_count: u32 = 0, short_write_at: ?usize = null, scratch: [4096]u8 = undefined, fn rpc(f: *FakeFile, req: cloud9.Client.Request) Session.Error!cloud9.Client.Result { f.calls += 1; switch (req) { .read => |r| { f.max_count = @max(f.max_count, r.count); if (r.offset >= f.len) return .{ .read = "" }; const n: usize = @min(@as(usize, r.count), f.len - @as(usize, @intCast(r.offset))); for (f.scratch[0..n], 0..) |*b, i| b.* = @truncate(r.offset + i); return .{ .read = f.scratch[0..n] }; }, .write => |w| { f.max_count = @max(f.max_count, @as(u32, @intCast(w.data.len))); if (f.short_write_at) |at| { if (w.offset + w.data.len > at) { const n: usize = if (w.offset >= at) 0 else @intCast(at - w.offset); return .{ .write = @intCast(n) }; } } return .{ .write = @intCast(w.data.len) }; }, else => unreachable, } } }; test "read chunks by max_chunk and stops at a short read" { var f: FakeFile = .{ .len = 2500 }; var buf: [4000]u8 = undefined; const n = try readWith(&f, FakeFile.rpc, 7, 0, &buf, 1000); try testing.expectEqual(@as(usize, 2500), n); try testing.expectEqual(@as(usize, 3), f.calls); // 1000, 1000, 500 (short → stop) try testing.expectEqual(@as(u32, 1000), f.max_count); for (buf[0..n], 0..) |b, i| try testing.expectEqual(@as(u8, @truncate(i)), b); // Reading exactly up to a chunk boundary uses one call per chunk and no more. f = .{ .len = 2000 }; try testing.expectEqual(@as(usize, 2000), try readWith(&f, FakeFile.rpc, 7, 0, buf[0..2000], 1000)); try testing.expectEqual(@as(usize, 2), f.calls); // Offset past EOF → 0. f = .{ .len = 10 }; try testing.expectEqual(@as(usize, 0), try readWith(&f, FakeFile.rpc, 7, 50, &buf, 1000)); } test "write chunks and stops at a short write" { var f: FakeFile = .{ .len = 0 }; var data: [2500]u8 = undefined; for (&data, 0..) |*b, i| b.* = @truncate(i); try testing.expectEqual(@as(usize, 2500), try writeWith(&f, FakeFile.rpc, 7, 0, &data, 1000)); try testing.expectEqual(@as(usize, 3), f.calls); try testing.expectEqual(@as(u32, 1000), f.max_count); f = .{ .len = 0, .short_write_at = 1500 }; try testing.expectEqual(@as(usize, 1500), try writeWith(&f, FakeFile.rpc, 7, 0, &data, 1000)); try testing.expectEqual(@as(usize, 2), f.calls); } // -- in-process server test --------------------------------------------------------- /// A tiny 9P2000 backend on a cloud9.Server: answers version/attach/walk/stat/open/ /// read/clunk/remove with canned data. Runs in its own thread over a socketpair. const FakeServer = struct { fd: i32, msize: u32, max_read_count: u32 = 0, file_len: usize, const file_qid: cloud9.Qid = .{ .type = 0, .version = 3, .path = 0x1234 }; const dir_qid: cloud9.Qid = .{ .type = cloud9.qtdir, .version = 1, .path = 0x1 }; fn run(fs: *FakeServer) void { fs.loop() catch |e| std.debug.print("fake server: {s}\n", .{@errorName(e)}); _ = linux.close(fs.fd); } fn loop(fs: *FakeServer) !void { const gpa = testing.allocator; const in = try gpa.alloc(u8, fs.msize); defer gpa.free(in); const out = try gpa.alloc(u8, fs.msize * 2); defer gpa.free(out); var srv: cloud9.Server = .init(.{ .in = in, .out = out }); var tmp: [4096]u8 = undefined; var data: [8192]u8 = undefined; while (true) { while (try srv.receive()) |req| { const tag = req.tag; switch (req.msg) { .tversion => |m| try srv.negotiate(m.msize, m.version), .tattach => try srv.reply(tag, .{ .rattach = .{ .qid = dir_qid } }), .twalk => |m| { var wq: [cloud9.max_welem]cloud9.Qid = @splat(dir_qid); var n: u16 = 0; for (m.wname[0..m.nwname]) |name| { if (std.mem.eql(u8, name, "file")) { wq[n] = file_qid; } else if (std.mem.eql(u8, name, "dir")) { wq[n] = dir_qid; } else break; n += 1; } if (n == 0 and m.nwname != 0) { try srv.reply(tag, .{ .rerror = .{ .ename = "file does not exist" } }); } else { try srv.reply(tag, .{ .rwalk = .{ .nwqid = n, .wqid = wq } }); } }, .tstat => try srv.reply(tag, .{ .rstat = .{ .stat = .{ .type = 0, .dev = 0, .qid = file_qid, .mode = 0o644, .atime = 1, .mtime = 2, .length = fs.file_len, .name = "file", .uid = "u", .gid = "g", .muid = "u", } } }), .topen => |m| try srv.reply(tag, .{ .ropen = .{ .qid = file_qid, .iounit = if (m.mode == cloud9.owrite) 700 else 0 } }), .tread => |m| { fs.max_read_count = @max(fs.max_read_count, m.count); var n: usize = 0; if (m.offset < fs.file_len) n = @min(@as(usize, m.count), fs.file_len - @as(usize, @intCast(m.offset))); n = @min(n, data.len); for (data[0..n], 0..) |*b, i| b.* = @truncate(m.offset + i); try srv.reply(tag, .{ .rread = .{ .data = data[0..n] } }); }, .twrite => |m| try srv.reply(tag, .{ .rwrite = .{ .count = @intCast(m.data.len) } }), .tclunk => try srv.reply(tag, .rclunk), .tremove => try srv.reply(tag, .{ .rerror = .{ .ename = "permission denied" } }), .twstat => try srv.reply(tag, .rwstat), // A flush is the test's "hang up now" signal. .tflush => return, else => try srv.reply(tag, .{ .rerror = .{ .ename = "not supported" } }), } srv.release(); } while (srv.output().len != 0) { const o = srv.output(); const rc = linux.write(fs.fd, o.ptr, o.len); if (linux.errno(rc) != .SUCCESS) return error.Write; srv.wrote(rc); } const rc = linux.read(fs.fd, &tmp, tmp.len); if (linux.errno(rc) != .SUCCESS) return error.Read; if (rc == 0) return; if (srv.push(tmp[0..rc]) != rc) return error.Overflow; } } }; test "session against an in-process cloud9.Server" { var fds: [2]i32 = undefined; try testing.expectEqual(linux.E.SUCCESS, linux.errno(linux.socketpair(linux.AF.UNIX, linux.SOCK.STREAM | linux.SOCK.CLOEXEC, 0, &fds))); var fs: FakeServer = .{ .fd = fds[1], .msize = 8192, .file_len = 20_000 }; const th = try std.Thread.spawn(.{}, FakeServer.run, .{&fs}); var s = try Session.connect(testing.allocator, .{ .fd = fds[0] }, 8192); defer { s.deinit(); th.join(); } try testing.expectEqual(@as(u32, 8192), s.msize); const root = try s.attach(0, "me", ""); try testing.expectEqual(FakeServer.dir_qid.path, root.path); // Plain rpc + stat borrowing the input buffer. const fid = s.allocFid(); const w = try s.walk(0, fid, &.{"file"}); try testing.expectEqual(@as(u16, 1), w.nwqid); try testing.expectEqual(FakeServer.file_qid.path, w.wqid[0].path); const st = try s.stat(fid); try testing.expectEqualStrings("file", st.name); try testing.expectEqual(@as(u64, 20_000), st.length); // Chunked read: 20000 bytes at maxRead = msize - 11 = 8181 per chunk. _ = try s.open(fid, cloud9.oread); const buf = try testing.allocator.alloc(u8, 30_000); defer testing.allocator.free(buf); const n = try s.read(fid, 0, buf); try testing.expectEqual(@as(usize, 20_000), n); for (buf[0..n], 0..) |b, i| try testing.expectEqual(@as(u8, @truncate(i)), b); try testing.expectEqual(@as(u32, 8181), fs.max_read_count); try testing.expectEqual(@as(usize, 0), try s.read(fid, 20_000, buf)); // iounit from open bounds the chunk. const wfid = try s.clone(fid); _ = try s.open(wfid, cloud9.owrite); fs.max_read_count = 0; _ = try s.read(wfid, 0, buf[0..3000]); try testing.expectEqual(@as(u32, 700), fs.max_read_count); try testing.expectEqual(@as(usize, 3000), try s.write(wfid, 0, buf[0..3000])); // Partial walk → error.Nine with a "not exist" ename → ENOENT. const pfid = s.allocFid(); try testing.expectError(error.Nine, s.walk(0, pfid, &.{ "dir", "nope" })); try testing.expectEqual(linux.E.NOENT, s.errno()); try testing.expectEqualStrings("file does not exist", s.ename[0..s.ename_len]); s.freeFid(pfid); // Server Rerror → error.Nine, ename copied, fid freed by remove even on error. try testing.expectError(error.Nine, s.remove(wfid)); try testing.expectEqual(linux.E.ACCES, s.errno()); try testing.expectEqual(wfid, s.allocFid()); // recycled s.freeFid(wfid); // Unsupported op → "not supported" → ENOTSUP; a plain wstat succeeds. try testing.expectError(error.Nine, s.rpc(.{ .auth = .{ .afid = 5, .uname = "me" } })); try testing.expectEqual(linux.E.OPNOTSUPP, s.errno()); try s.wstat(fid, dontcare); try s.clunk(fid); try testing.expectEqual(fid, s.allocFid()); s.freeFid(fid); // A clone bound to a fid that then fails to walk must release the fid. const before = s.next_fid; const cfid = s.allocFid(); s.freeFid(cfid); try testing.expectError(error.Nine, s.walk(0, cfid, &.{"nope"})); try testing.expectEqual(before, s.next_fid); // The server hanging up makes the pending rpc fail with error.Closed. try testing.expectError(error.Closed, s.rpc(.{ .flush = .{ .oldtag = 0 } })); }