From 7d3cbefde656d5520067d56eeb44a8ba1f39d672 Mon Sep 17 00:00:00 2001 From: tjpcc Date: Sat, 12 Aug 2023 10:47:51 -0600 Subject: multi-protocol client Fixes #4 --- README.md | 1 + client.go | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ finger/client.go | 9 +++++- gemini/client.go | 10 +++++-- gemini/response.go | 2 +- gopher/client.go | 2 ++ spartan/client.go | 8 +++-- 7 files changed, 112 insertions(+), 7 deletions(-) create mode 100644 client.go diff --git a/README.md b/README.md index f07fe61..56fb71f 100644 --- a/README.md +++ b/README.md @@ -32,6 +32,7 @@ sliderule is carefully structured as composable building blocks. The top-level p * a "Server" interface type * a "Handler" abstraction * a "Middleware" abstraction +* a "Client" which handles all the protocols known to sliderule * some useful Handler wrappers: a router, request filtering, falling through a list of handlers ## Protocols diff --git a/client.go b/client.go new file mode 100644 index 0000000..3631bc5 --- /dev/null +++ b/client.go @@ -0,0 +1,87 @@ +package sliderule + +import ( + "crypto/tls" + "errors" + "fmt" + neturl "net/url" + + "tildegit.org/tjp/sliderule/finger" + "tildegit.org/tjp/sliderule/gemini" + "tildegit.org/tjp/sliderule/gopher" + "tildegit.org/tjp/sliderule/internal/types" + "tildegit.org/tjp/sliderule/spartan" +) + +type protocolClient interface { + RoundTrip(*Request) (*Response, error) + IsRedirect(*Response) bool +} + +// Client is a multi-protocol client which handles all protocols known to sliderule. +type Client struct { + MaxRedirects int + + protos map[string]protocolClient +} + +const DefaultMaxRedirects int = 2 + +var ExceededMaxRedirects = errors.New("Client: exceeded MaxRedirects") + +// NewClient builds a Client object. +// +// tlsConf may be nil, in which case gemini requests connections will not be made +// with any client certificate. +func NewClient(tlsConf *tls.Config) Client { + return Client{ + protos: map[string]protocolClient{ + "finger": finger.Client{}, + "gopher": gopher.Client{}, + "gemini": gemini.NewClient(tlsConf), + "spartan": spartan.NewClient(), + }, + MaxRedirects: DefaultMaxRedirects, + } +} + +// RoundTrip sends a single request and returns the repsonse. +// +// If the response is a redirect it will be returned, rather than fetched. +func (c Client) RoundTrip(request *Request) (*Response, error) { + pc, ok := c.protos[request.Scheme] + if !ok { + return nil, fmt.Errorf("unrecognized protocol: %s", request.Scheme) + } + return pc.RoundTrip(request) +} + +// Fetch collects a resource from a URL including following any redirects. +func (c Client) Fetch(url string) (*Response, error) { + u, err := neturl.Parse(url) + if err != nil { + return nil, err + } + + for i := 0; i <= c.MaxRedirects; i += 1 { + response, err := c.RoundTrip(&types.Request{URL: u}) + if err != nil { + return nil, err + } + + if !c.protos[u.Scheme].IsRedirect(response) { + return response, nil + } + + prev := u + u, err = neturl.Parse(response.Meta.(string)) + if err != nil { + return nil, err + } + if u.Scheme == "" { + u.Scheme = prev.Scheme + } + } + + return nil, ExceededMaxRedirects +} diff --git a/finger/client.go b/finger/client.go index 75a382f..bd1e3bf 100644 --- a/finger/client.go +++ b/finger/client.go @@ -37,7 +37,12 @@ func (c Client) RoundTrip(request *types.Request) (*types.Response, error) { request.RemoteAddr = conn.RemoteAddr() request.TLSState = nil - if _, err := conn.Write([]byte(strings.TrimPrefix(request.Path, "/") + "\r\n")); err != nil { + username := request.User.String() + if username == "" { + username = strings.TrimPrefix(request.Path, "/") + } + + if _, err := conn.Write([]byte(username + "\r\n")); err != nil { return nil, err } @@ -57,3 +62,5 @@ func (c Client) Fetch(query string) (*types.Response, error) { } return c.RoundTrip(req) } + +func (c Client) IsRedirect(_ *types.Response) bool { return false } diff --git a/gemini/client.go b/gemini/client.go index 34d5839..0a621dd 100644 --- a/gemini/client.go +++ b/gemini/client.go @@ -54,7 +54,7 @@ func (client Client) RoundTrip(request *types.Request) (*types.Response, error) } tlsConf := client.tlsConf - if (tlsConf == nil) { + if tlsConf == nil { tlsConf = &tls.Config{InsecureSkipVerify: true} } @@ -102,12 +102,12 @@ func (c Client) Fetch(url string) (*types.Response, error) { if err != nil { return nil, err } - if ResponseCategoryForStatus(response.Status) != ResponseCategoryRedirect { + if !c.IsRedirect(response) { return response, nil } prev := u - u, err = neturl.Parse(url) + u, err = neturl.Parse(response.Meta.(string)) if err != nil { return nil, err } @@ -116,3 +116,7 @@ func (c Client) Fetch(url string) (*types.Response, error) { return nil, ExceededMaxRedirects } + +func (c Client) IsRedirect(response *types.Response) bool { + return ResponseCategoryForStatus(response.Status) == ResponseCategoryRedirect +} diff --git a/gemini/response.go b/gemini/response.go index 13f493a..b3e53aa 100644 --- a/gemini/response.go +++ b/gemini/response.go @@ -44,7 +44,7 @@ const ( ) func ResponseCategoryForStatus(status types.Status) ResponseCategory { - return ResponseCategory(status / 10) + return ResponseCategory((status / 10) * 10) } const ( diff --git a/gopher/client.go b/gopher/client.go index 5ef54ff..a5c4228 100644 --- a/gopher/client.go +++ b/gopher/client.go @@ -63,3 +63,5 @@ func (c Client) Fetch(url string) (*types.Response, error) { } return c.RoundTrip(&types.Request{URL: u}) } + +func (c Client) IsRedirect(_ *types.Response) bool { return false } diff --git a/spartan/client.go b/spartan/client.go index e3025ee..affcf95 100644 --- a/spartan/client.go +++ b/spartan/client.go @@ -100,12 +100,12 @@ func (c Client) Fetch(url string) (*types.Response, error) { if err != nil { return nil, err } - if response.Status != StatusRedirect { + if !c.IsRedirect(response) { return response, nil } prev := u - u, err = neturl.Parse(url) + u, err = neturl.Parse(response.Meta.(string)) if err != nil { return nil, err } @@ -115,6 +115,10 @@ func (c Client) Fetch(url string) (*types.Response, error) { return nil, ExceededMaxRedirects } +func (c Client) IsRedirect(response *types.Response) bool { + return response.Status == StatusRedirect +} + type devnull struct{} func (_ devnull) Read(p []byte) (int, error) { -- cgit v1.2.3