implement header matching in proxy.ini

This commit is contained in:
Emil Lerch 2023-05-31 10:18:09 -07:00
parent 2004d97919
commit 1f9fd19771
Signed by: lobo
GPG Key ID: A7B62D657EF764F8
3 changed files with 62 additions and 7 deletions

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@ -38,6 +38,11 @@ pub const ZigRequest = struct {
headers: []Header, headers: []Header,
}; };
pub const ZigHeader = struct {
name: []u8,
value: []u8,
};
pub const ZigResponse = struct { pub const ZigResponse = struct {
body: *std.ArrayList(u8), body: *std.ArrayList(u8),
headers: *std.StringHashMap([]const u8), headers: *std.StringHashMap([]const u8),
@ -55,6 +60,13 @@ pub fn zigInit(parent_allocator: *anyopaque) callconv(.C) void {
allocator = @ptrCast(*std.mem.Allocator, @alignCast(@alignOf(*std.mem.Allocator), parent_allocator)); allocator = @ptrCast(*std.mem.Allocator, @alignCast(@alignOf(*std.mem.Allocator), parent_allocator));
} }
pub fn toZigHeader(header: Header) ZigHeader {
return .{
.name = header.name_ptr[0..header.name_len],
.value = header.value_ptr[0..header.value_len],
};
}
/// Converts a StringHashMap to the structure necessary for passing through the /// Converts a StringHashMap to the structure necessary for passing through the
/// C boundary. This will be called automatically for you via the handleRequest function /// C boundary. This will be called automatically for you via the handleRequest function
/// and is also used by the main processing loop to coerce request headers /// and is also used by the main processing loop to coerce request headers

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@ -40,7 +40,16 @@ fn handleRequest(allocator: std.mem.Allocator, request: interface.ZigRequest, re
// setup // setup
var response_writer = response.body.writer(); var response_writer = response.body.writer();
// real work // real work
response_writer.print(" {d}", .{request.headers.len}) catch unreachable; for (request.headers) |h| {
const header = interface.toZigHeader(h);
if (!std.ascii.eqlIgnoreCase(header.name, "host")) continue;
if (std.mem.startsWith(u8, header.value, "iam")) {
try response_writer.print("iam response", .{});
return;
}
break;
}
try response_writer.print(" {d}", .{request.headers.len});
try response.headers.put("X-custom-foo", "bar"); try response.headers.put("X-custom-foo", "bar");
log.info("handlerequest header count {d}", .{response.headers.count()}); log.info("handlerequest header count {d}", .{response.headers.count()});
} }

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@ -37,7 +37,7 @@ const FullReturn = struct {
// applies // applies
const Executor = struct { const Executor = struct {
// configuration // configuration
target_prefix: []const u8, match_data: []const u8,
path: [:0]const u8, path: [:0]const u8,
// fields used at runtime to do real work // fields used at runtime to do real work
@ -62,8 +62,7 @@ var parsed_config: config.ParsedConfig = undefined;
/// Serves a single request. Finds executor, marshalls request data for the C /// Serves a single request. Finds executor, marshalls request data for the C
/// interface, calls the executor and marshalls data back /// interface, calls the executor and marshalls data back
fn serve(allocator: *std.mem.Allocator, response: *std.http.Server.Response) !*FullReturn { fn serve(allocator: *std.mem.Allocator, response: *std.http.Server.Response) !*FullReturn {
// if (some path routing thing) { const executor = try getExecutor(response.request.target, response.request.headers);
const executor = try getExecutor(response.request.target);
if (executor.zigInitFn) |f| if (executor.zigInitFn) |f|
f(allocator); f(allocator);
@ -115,10 +114,10 @@ fn serve(allocator: *std.mem.Allocator, response: *std.http.Server.Response) !*F
} }
/// Gets and executor based on request data /// Gets and executor based on request data
fn getExecutor(requested_path: []const u8) !*Executor { fn getExecutor(requested_path: []const u8, headers: std.http.Headers) !*Executor {
var executor = blk: { var executor = blk: {
for (executors) |*exec| { for (executors) |*exec| {
if (std.mem.startsWith(u8, requested_path, exec.target_prefix)) { if (executorIsMatch(exec.match_data, requested_path, headers)) {
break :blk exec; break :blk exec;
} }
} }
@ -154,6 +153,41 @@ fn getExecutor(requested_path: []const u8) !*Executor {
return executor; return executor;
} }
fn executorIsMatch(match_data: []const u8, requested_path: []const u8, headers: std.http.Headers) bool {
if (!std.mem.containsAtLeast(u8, match_data, 1, ":")) {
// match_data does not have a ':'. This means this is a straight path, without
// any header requirement. We can simply return a match prefix on the
// requested path
const rc = std.mem.startsWith(u8, requested_path, match_data);
if (rc) log.debug("executor match for path prefix '{s}'", .{match_data});
return rc;
}
const colon = std.mem.indexOf(u8, match_data, ":").?;
const header_needle = match_data[0..colon];
const header_inx = headers.firstIndexOf(header_needle) orelse return false;
// Apparently std.mem.split will return an empty first when the haystack starts
// with the delimiter
var split = std.mem.split(u8, std.mem.trim(u8, match_data[colon + 1 ..], "\t "), " ");
const header_value_needle = split.first();
const path_needle = split.next() orelse {
std.log.warn(
"Incorrect configuration. Header matching requires both header value and path prefix, space delimited. Key was '{s}'",
.{match_data},
);
return false;
};
// match_data includes some sort of header match as well. We assume the
// header match is a full match on the key (handled above)
// but a prefix match on the value
const request_header_value = headers.list.items[header_inx].value;
// (shoud this be case insensitive?)
if (!std.mem.startsWith(u8, request_header_value, header_value_needle)) return false;
// header value matches...return the path prefix match
const rc = std.mem.startsWith(u8, requested_path, path_needle);
if (rc) log.debug("executor match for header and path prefix '{s}'", .{match_data});
return rc;
}
/// Loads all optional symbols from the dynamic library. This has two entry /// Loads all optional symbols from the dynamic library. This has two entry
/// points, though the logic around the primary request handler is slighly /// points, though the logic around the primary request handler is slighly
/// different in each case so we can't combine those two. /// different in each case so we can't combine those two.
@ -346,7 +380,7 @@ fn loadConfig(allocator: std.mem.Allocator) ![]Executor {
defer al.deinit(); defer al.deinit();
for (parsed_config.key_value_map.keys(), parsed_config.key_value_map.values()) |k, v| { for (parsed_config.key_value_map.keys(), parsed_config.key_value_map.values()) |k, v| {
al.appendAssumeCapacity(.{ al.appendAssumeCapacity(.{
.target_prefix = k, .match_data = k,
.path = v, .path = v,
}); });
} }