diff options
Diffstat (limited to '')
| -rw-r--r-- | usem.go (renamed from sem.go) | 0 | ||||
| -rw-r--r-- | wsc.go (renamed from ws.go) | 245 | ||||
| -rw-r--r-- | wsh.go | 165 | ||||
| -rw-r--r-- | wsp.go | 85 | ||||
| -rw-r--r-- | wsx.go | 59 |
5 files changed, 319 insertions, 235 deletions
@@ -1,5 +1,5 @@ /* - * Primary WebSocket routines + * WebSocket connection routine * * Copyright (C) 2024 Runxi Yu <https://runxiyu.org> * SPDX-License-Identifier: AGPL-3.0-or-later @@ -18,257 +18,23 @@ * along with this program. If not, see <https://www.gnu.org/licenses/>. */ -/* - * The message format is a WebSocket message separated with spaces. - * The contents of each field could contain anything other than spaces, - * The first character of each argument cannot be a colon. As an exception, the - * last argument may contain spaces and the first character thereof may be a - * colon, if the argument is prefixed with a colon. The colon used for the - * prefix is not considered part of the content of the message. For example, in - * - * SQUISH POP :cat purr!! - * - * the first field is "SQUISH", the second field is "POP", and the third - * field is "cat purr!!". - * - * It is essentially an RFC 1459 IRC message without trailing CR-LF and - * without prefixes. See section 2.3.1 of RFC 1459 for an approximate - * BNF representation. - * - * The reason this was chosen instead of using protobuf etc. is that it - * is simple to parse without external libraries, and it also happens to - * be a format I'm very familiar with, having extensively worked with the - * IRC protocol. - */ - package main import ( "context" "errors" "fmt" - "log" - "net/http" "sync" "time" "github.com/coder/websocket" - "github.com/google/uuid" - "github.com/jackc/pgx/v5" ) -func writeText(ctx context.Context, c *websocket.Conn, msg string) error { - err := c.Write(ctx, websocket.MessageText, []byte(msg)) - if err != nil { - return fmt.Errorf("error writing to connection: %w", err) - } - return nil -} - -/* - * Handle requests to the WebSocket endpoint and establish a connection. - * Authentication is handled here, but afterwards, the connection is really - * handled in handleConn. - */ -func handleWs(w http.ResponseWriter, req *http.Request) { - wsOptions := &websocket.AcceptOptions{ - Subprotocols: []string{"cca1"}, - } //exhaustruct:ignore - c, err := websocket.Accept( - w, - req, - wsOptions, - ) - if err != nil { - wstr(w, http.StatusBadRequest, "This endpoint only supports valid WebSocket connections.") - return - } - defer func() { - _ = c.CloseNow() - }() - - fake := false - - sessionCookie, err := req.Cookie("session") - if errors.Is(err, http.ErrNoCookie) { - if config.Auth.Fake == 0 { - err := writeText(req.Context(), c, "U") - if err != nil { - log.Println(err) - } - return - } - fake = true - } else if err != nil { - err := writeText(req.Context(), c, "E :Error fetching cookie") - if err != nil { - log.Println(err) - } - return - } - - var userID string - var session string - var expr int - - if fake { - switch config.Auth.Fake { - case 9080: - _uuid, err := uuid.NewRandom() - if err != nil { - log.Println(err) - return - } - userID = _uuid.String() - case 4712: - userID = "fake" - default: - panic("not supposed to happen") - } - session, err = randomString(20) - if err != nil { - log.Println(err) - return - } - _, err = db.Exec( - req.Context(), - "INSERT INTO users (id, name, email, department, session, expr) VALUES ($1, $2, $3, $4, $5, $6)", - userID, - "Fake User", - "fake@runxiyu.org", - "Y11", - session, - time.Now().Add(time.Duration(config.Auth.Expr)*time.Second).Unix(), - ) - if err != nil && config.Auth.Fake != 4712 { - /* TODO check pgerr */ - err := writeText(req.Context(), c, "E :Database error while writing fake account info") - if err != nil { - log.Println(err) - } - return - } - err = writeText(req.Context(), c, "FAKE "+userID+" "+session) - if err != nil { - log.Println(err) - return - } - } else { - session = sessionCookie.Value - err = db.QueryRow( - req.Context(), - "SELECT id, expr FROM users WHERE session = $1", - session, - ).Scan(&userID, &expr) - if errors.Is(err, pgx.ErrNoRows) { - err := writeText(req.Context(), c, "U") - if err != nil { - log.Println(err) - } - return - } else if err != nil { - err := writeText(req.Context(), c, "E :Database error while selecting session") - if err != nil { - log.Println(err) - } - return - } - } - - /* - * Now that we have an authenticated request, this WebSocket connection - * may be simply associated with the session and userID. - * TODO: There are various race conditions that could occur if one user - * creates multiple connections, with the same or different session - * cookies. The last situation could occur in normal use when a user - * opens multiple instances of the page in one browser, and is not - * unique to custom clients or malicious users. Some effort must be - * taken to ensure that each user may only have one connection at a - * time. - */ - err = handleConn( - req.Context(), - c, - session, - userID, - ) - if err != nil { - log.Printf("%v", err) - return - } -} - -/* - * Split an IRC-style message of type []byte into type []string where each - * element is a complete argument. Generally, arguments are separated by - * spaces, and an argument that begins with a ':' causes the rest of the - * line to be treated as a single argument. - */ -func splitMsg(b *[]byte) []string { - mar := make([]string, 0, config.Perf.MessageArgumentsCap) - elem := make([]byte, 0, config.Perf.MessageBytesCap) - for i, c := range *b { - switch c { - case ' ': - if (*b)[i+1] == ':' { - mar = append(mar, string(elem)) - mar = append(mar, string((*b)[i+2:])) - goto endl - } - mar = append(mar, string(elem)) - elem = make([]byte, 0, config.Perf.MessageBytesCap) - default: - elem = append(elem, c) - } - } - mar = append(mar, string(elem)) -endl: - return mar -} - -func baseReportError(ctx context.Context, conn *websocket.Conn, e string) error { - err := writeText(ctx, conn, "E :"+e) - if err != nil { - return fmt.Errorf("error reporting protocol violation: %w", err) - } - err = conn.Close(websocket.StatusProtocolError, e) - if err != nil { - return fmt.Errorf("error closing websocket: %w", err) - } - return nil -} - -type reportErrorT func(e string) error - -func makeReportError(ctx context.Context, conn *websocket.Conn) reportErrorT { - return func(e string) error { - return baseReportError(ctx, conn, e) - } -} - type errbytesT struct { err error bytes *[]byte } -var ( - cancelPool = make(map[string](*context.CancelFunc)) - /* - * Normal Go maps are not thread safe, so we protect large cancelPool - * operations such as addition and deletion under a RWMutex. - */ - cancelPoolLock sync.RWMutex -) - -func propagateSelectedUpdate(courseID int) { - course := courses[courseID] - course.UsemsLock.RLock() - defer course.UsemsLock.RUnlock() - for _, usem := range course.Usems { - usem.set() - } -} - /* * The actual logic in handling the connection, after authentication has been * completed. @@ -489,3 +255,12 @@ func handleConn( } } } + +var ( + cancelPool = make(map[string](*context.CancelFunc)) + /* + * Normal Go maps are not thread safe, so we protect large cancelPool + * operations such as addition and deletion under a RWMutex. + */ + cancelPoolLock sync.RWMutex +) @@ -0,0 +1,165 @@ +/* + * WebSocket endpoint handler + * + * Copyright (C) 2024 Runxi Yu <https://runxiyu.org> + * SPDX-License-Identifier: AGPL-3.0-or-later + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +package main + +import ( + "errors" + "log" + "net/http" + "time" + + "github.com/coder/websocket" + "github.com/google/uuid" + "github.com/jackc/pgx/v5" +) + +/* + * Handle requests to the WebSocket endpoint and establish a connection. + * Authentication is handled here, but afterwards, the connection is really + * handled in handleConn. + */ +func handleWs(w http.ResponseWriter, req *http.Request) { + wsOptions := &websocket.AcceptOptions{ + Subprotocols: []string{"cca1"}, + } //exhaustruct:ignore + c, err := websocket.Accept( + w, + req, + wsOptions, + ) + if err != nil { + wstr(w, http.StatusBadRequest, "This endpoint only supports valid WebSocket connections.") + return + } + defer func() { + _ = c.CloseNow() + }() + + fake := false + + sessionCookie, err := req.Cookie("session") + if errors.Is(err, http.ErrNoCookie) { + if config.Auth.Fake == 0 { + err := writeText(req.Context(), c, "U") + if err != nil { + log.Println(err) + } + return + } + fake = true + } else if err != nil { + err := writeText(req.Context(), c, "E :Error fetching cookie") + if err != nil { + log.Println(err) + } + return + } + + var userID string + var session string + var expr int + + if fake { + switch config.Auth.Fake { + case 9080: + _uuid, err := uuid.NewRandom() + if err != nil { + log.Println(err) + return + } + userID = _uuid.String() + case 4712: + userID = "fake" + default: + panic("not supposed to happen") + } + session, err = randomString(20) + if err != nil { + log.Println(err) + return + } + _, err = db.Exec( + req.Context(), + "INSERT INTO users (id, name, email, department, session, expr) VALUES ($1, $2, $3, $4, $5, $6)", + userID, + "Fake User", + "fake@runxiyu.org", + "Y11", + session, + time.Now().Add(time.Duration(config.Auth.Expr)*time.Second).Unix(), + ) + if err != nil && config.Auth.Fake != 4712 { + /* TODO check pgerr */ + err := writeText(req.Context(), c, "E :Database error while writing fake account info") + if err != nil { + log.Println(err) + } + return + } + err = writeText(req.Context(), c, "FAKE "+userID+" "+session) + if err != nil { + log.Println(err) + return + } + } else { + session = sessionCookie.Value + err = db.QueryRow( + req.Context(), + "SELECT id, expr FROM users WHERE session = $1", + session, + ).Scan(&userID, &expr) + if errors.Is(err, pgx.ErrNoRows) { + err := writeText(req.Context(), c, "U") + if err != nil { + log.Println(err) + } + return + } else if err != nil { + err := writeText(req.Context(), c, "E :Database error while selecting session") + if err != nil { + log.Println(err) + } + return + } + } + + /* + * Now that we have an authenticated request, this WebSocket connection + * may be simply associated with the session and userID. + * TODO: There are various race conditions that could occur if one user + * creates multiple connections, with the same or different session + * cookies. The last situation could occur in normal use when a user + * opens multiple instances of the page in one browser, and is not + * unique to custom clients or malicious users. Some effort must be + * taken to ensure that each user may only have one connection at a + * time. + */ + err = handleConn( + req.Context(), + c, + session, + userID, + ) + if err != nil { + log.Printf("%v", err) + return + } +} @@ -0,0 +1,85 @@ +/* + * WebSocket-based protocol auxiliary functions + * + * Copyright (C) 2024 Runxi Yu <https://runxiyu.org> + * SPDX-License-Identifier: AGPL-3.0-or-later + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +package main + +import ( + "context" + "fmt" + + "github.com/coder/websocket" +) + +/* + * Split an IRC-style message of type []byte into type []string where each + * element is a complete argument. Generally, arguments are separated by + * spaces, and an argument that begins with a ':' causes the rest of the + * line to be treated as a single argument. + */ +func splitMsg(b *[]byte) []string { + mar := make([]string, 0, config.Perf.MessageArgumentsCap) + elem := make([]byte, 0, config.Perf.MessageBytesCap) + for i, c := range *b { + switch c { + case ' ': + if (*b)[i+1] == ':' { + mar = append(mar, string(elem)) + mar = append(mar, string((*b)[i+2:])) + goto endl + } + mar = append(mar, string(elem)) + elem = make([]byte, 0, config.Perf.MessageBytesCap) + default: + elem = append(elem, c) + } + } + mar = append(mar, string(elem)) +endl: + return mar +} + +func baseReportError(ctx context.Context, conn *websocket.Conn, e string) error { + err := writeText(ctx, conn, "E :"+e) + if err != nil { + return fmt.Errorf("error reporting protocol violation: %w", err) + } + err = conn.Close(websocket.StatusProtocolError, e) + if err != nil { + return fmt.Errorf("error closing websocket: %w", err) + } + return nil +} + +type reportErrorT func(e string) error + +func makeReportError(ctx context.Context, conn *websocket.Conn) reportErrorT { + return func(e string) error { + return baseReportError(ctx, conn, e) + } +} + +func propagateSelectedUpdate(courseID int) { + course := courses[courseID] + course.UsemsLock.RLock() + defer course.UsemsLock.RUnlock() + for _, usem := range course.Usems { + usem.set() + } +} @@ -0,0 +1,59 @@ +/* + * Generic WebSocket auxiliary functions + * + * Copyright (C) 2024 Runxi Yu <https://runxiyu.org> + * SPDX-License-Identifier: AGPL-3.0-or-later + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +/* + * The message format is a WebSocket message separated with spaces. + * The contents of each field could contain anything other than spaces, + * The first character of each argument cannot be a colon. As an exception, the + * last argument may contain spaces and the first character thereof may be a + * colon, if the argument is prefixed with a colon. The colon used for the + * prefix is not considered part of the content of the message. For example, in + * + * SQUISH POP :cat purr!! + * + * the first field is "SQUISH", the second field is "POP", and the third + * field is "cat purr!!". + * + * It is essentially an RFC 1459 IRC message without trailing CR-LF and + * without prefixes. See section 2.3.1 of RFC 1459 for an approximate + * BNF representation. + * + * The reason this was chosen instead of using protobuf etc. is that it + * is simple to parse without external libraries, and it also happens to + * be a format I'm very familiar with, having extensively worked with the + * IRC protocol. + */ + +package main + +import ( + "context" + "fmt" + + "github.com/coder/websocket" +) + +func writeText(ctx context.Context, c *websocket.Conn, msg string) error { + err := c.Write(ctx, websocket.MessageText, []byte(msg)) + if err != nil { + return fmt.Errorf("error writing to connection: %w", err) + } + return nil +} |