From e40831a0023705885643284b574913e08a59f496 Mon Sep 17 00:00:00 2001 From: nicm Date: Thu, 11 Feb 2021 08:28:45 +0000 Subject: Move file handling protocol stuff all into file.c so it can be reused more easily. --- file.c | 434 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 408 insertions(+), 26 deletions(-) (limited to 'file.c') diff --git a/file.c b/file.c index 0d25db03..495568fa 100644 --- a/file.c +++ b/file.c @@ -30,10 +30,17 @@ #include "tmux.h" +/* + * IPC file handling. Both client and server use the same data structures + * (client_file and client_files) to store list of active files. Most functions + * are for use either in client or server but not both. + */ + static int file_next_stream = 3; RB_GENERATE(client_files, client_file, entry, file_cmp); +/* Get path for file, either as given or from working directory. */ static char * file_get_path(struct client *c, const char *file) { @@ -46,6 +53,7 @@ file_get_path(struct client *c, const char *file) return (path); } +/* Tree comparison function. */ int file_cmp(struct client_file *cf1, struct client_file *cf2) { @@ -56,11 +64,47 @@ file_cmp(struct client_file *cf1, struct client_file *cf2) return (0); } +/* + * Create a file object in the client process - the peer is the server to send + * messages to. Check callback is fired when the file is finished with so the + * process can decide if it needs to exit (if it is waiting for files to + * flush). + */ struct client_file * -file_create(struct client *c, int stream, client_file_cb cb, void *cbdata) +file_create_with_peer(struct tmuxpeer *peer, struct client_files *files, + int stream, client_file_cb cb, void *cbdata) { struct client_file *cf; + cf = xcalloc(1, sizeof *cf); + cf->c = NULL; + cf->references = 1; + cf->stream = stream; + + cf->buffer = evbuffer_new(); + if (cf->buffer == NULL) + fatalx("out of memory"); + + cf->cb = cb; + cf->data = cbdata; + + cf->peer = peer; + cf->tree = files; + RB_INSERT(client_files, files, cf); + + return (cf); +} + +/* Create a file object in the server, communicating with the given client. */ +struct client_file * +file_create_with_client(struct client *c, int stream, client_file_cb cb, + void *cbdata) +{ + struct client_file *cf; + + if (c != NULL && (c->flags & CLIENT_ATTACHED)) + c = NULL; + cf = xcalloc(1, sizeof *cf); cf->c = c; cf->references = 1; @@ -74,6 +118,8 @@ file_create(struct client *c, int stream, client_file_cb cb, void *cbdata) cf->data = cbdata; if (cf->c != NULL) { + cf->peer = cf->c->peer; + cf->tree = &cf->c->files; RB_INSERT(client_files, &cf->c->files, cf); cf->c->references++; } @@ -81,6 +127,7 @@ file_create(struct client *c, int stream, client_file_cb cb, void *cbdata) return (cf); } +/* Free a file. */ void file_free(struct client_file *cf) { @@ -90,13 +137,15 @@ file_free(struct client_file *cf) evbuffer_free(cf->buffer); free(cf->path); - if (cf->c != NULL) { - RB_REMOVE(client_files, &cf->c->files, cf); + if (cf->tree != NULL) + RB_REMOVE(client_files, cf->tree, cf); + if (cf->c != NULL) server_client_unref(cf->c); - } + free(cf); } +/* Event to fire the done callback. */ static void file_fire_done_cb(__unused int fd, __unused short events, void *arg) { @@ -108,21 +157,22 @@ file_fire_done_cb(__unused int fd, __unused short events, void *arg) file_free(cf); } +/* Add an event to fire the done callback (used by the server). */ void file_fire_done(struct client_file *cf) { event_once(-1, EV_TIMEOUT, file_fire_done_cb, cf, NULL); } +/* Fire the read callback. */ void file_fire_read(struct client_file *cf) { - struct client *c = cf->c; - if (cf->cb != NULL) - cf->cb(c, cf->path, cf->error, 0, cf->buffer, cf->data); + cf->cb(cf->c, cf->path, cf->error, 0, cf->buffer, cf->data); } +/* Can this file be printed to? */ int file_can_print(struct client *c) { @@ -133,6 +183,7 @@ file_can_print(struct client *c) return (1); } +/* Print a message to a file. */ void file_print(struct client *c, const char *fmt, ...) { @@ -143,6 +194,7 @@ file_print(struct client *c, const char *fmt, ...) va_end(ap); } +/* Print a message to a file. */ void file_vprint(struct client *c, const char *fmt, va_list ap) { @@ -154,7 +206,7 @@ file_vprint(struct client *c, const char *fmt, va_list ap) find.stream = 1; if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL) { - cf = file_create(c, 1, NULL, NULL); + cf = file_create_with_client(c, 1, NULL, NULL); cf->path = xstrdup("-"); evbuffer_add_vprintf(cf->buffer, fmt, ap); @@ -169,6 +221,7 @@ file_vprint(struct client *c, const char *fmt, va_list ap) } } +/* Print a buffer to a file. */ void file_print_buffer(struct client *c, void *data, size_t size) { @@ -180,7 +233,7 @@ file_print_buffer(struct client *c, void *data, size_t size) find.stream = 1; if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL) { - cf = file_create(c, 1, NULL, NULL); + cf = file_create_with_client(c, 1, NULL, NULL); cf->path = xstrdup("-"); evbuffer_add(cf->buffer, data, size); @@ -195,6 +248,7 @@ file_print_buffer(struct client *c, void *data, size_t size) } } +/* Report an error to a file. */ void file_error(struct client *c, const char *fmt, ...) { @@ -209,7 +263,7 @@ file_error(struct client *c, const char *fmt, ...) find.stream = 2; if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL) { - cf = file_create(c, 2, NULL, NULL); + cf = file_create_with_client(c, 2, NULL, NULL); cf->path = xstrdup("-"); evbuffer_add_vprintf(cf->buffer, fmt, ap); @@ -226,19 +280,21 @@ file_error(struct client *c, const char *fmt, ...) va_end(ap); } +/* Write data to a file. */ void file_write(struct client *c, const char *path, int flags, const void *bdata, size_t bsize, client_file_cb cb, void *cbdata) { struct client_file *cf; - FILE *f; struct msg_write_open *msg; size_t msglen; int fd = -1; + u_int stream = file_next_stream++; + FILE *f; const char *mode; if (strcmp(path, "-") == 0) { - cf = file_create(c, file_next_stream++, cb, cbdata); + cf = file_create_with_client(c, stream, cb, cbdata); cf->path = xstrdup("-"); fd = STDOUT_FILENO; @@ -251,7 +307,7 @@ file_write(struct client *c, const char *path, int flags, const void *bdata, goto skip; } - cf = file_create(c, file_next_stream++, cb, cbdata); + cf = file_create_with_client(c, stream, cb, cbdata); cf->path = file_get_path(c, path); if (c == NULL || c->flags & CLIENT_ATTACHED) { @@ -286,7 +342,7 @@ skip: msg->fd = fd; msg->flags = flags; memcpy(msg + 1, cf->path, msglen - sizeof *msg); - if (proc_send(c->peer, MSG_WRITE_OPEN, -1, msg, msglen) != 0) { + if (proc_send(cf->peer, MSG_WRITE_OPEN, -1, msg, msglen) != 0) { free(msg); cf->error = EINVAL; goto done; @@ -298,18 +354,21 @@ done: file_fire_done(cf); } +/* Read a file. */ void file_read(struct client *c, const char *path, client_file_cb cb, void *cbdata) { struct client_file *cf; - FILE *f; struct msg_read_open *msg; - size_t msglen, size; + size_t msglen; int fd = -1; + u_int stream = file_next_stream++; + FILE *f; + size_t size; char buffer[BUFSIZ]; if (strcmp(path, "-") == 0) { - cf = file_create(c, file_next_stream++, cb, cbdata); + cf = file_create_with_client(c, stream, cb, cbdata); cf->path = xstrdup("-"); fd = STDIN_FILENO; @@ -322,7 +381,7 @@ file_read(struct client *c, const char *path, client_file_cb cb, void *cbdata) goto skip; } - cf = file_create(c, file_next_stream++, cb, cbdata); + cf = file_create_with_client(c, stream, cb, cbdata); cf->path = file_get_path(c, path); if (c == NULL || c->flags & CLIENT_ATTACHED) { @@ -358,7 +417,7 @@ skip: msg->stream = cf->stream; msg->fd = fd; memcpy(msg + 1, cf->path, msglen - sizeof *msg); - if (proc_send(c->peer, MSG_READ_OPEN, -1, msg, msglen) != 0) { + if (proc_send(cf->peer, MSG_READ_OPEN, -1, msg, msglen) != 0) { free(msg); cf->error = EINVAL; goto done; @@ -370,21 +429,21 @@ done: file_fire_done(cf); } +/* Push event, fired if there is more writing to be done. */ static void file_push_cb(__unused int fd, __unused short events, void *arg) { struct client_file *cf = arg; - struct client *c = cf->c; - if (~c->flags & CLIENT_DEAD) + if (cf->c == NULL || ~cf->c->flags & CLIENT_DEAD) file_push(cf); file_free(cf); } +/* Push uwritten data to the client for a file, if it will accept it. */ void file_push(struct client_file *cf) { - struct client *c = cf->c; struct msg_write_data *msg; size_t msglen, sent, left; struct msg_write_close close; @@ -400,21 +459,344 @@ file_push(struct client_file *cf) msg = xrealloc(msg, msglen); msg->stream = cf->stream; memcpy(msg + 1, EVBUFFER_DATA(cf->buffer), sent); - if (proc_send(c->peer, MSG_WRITE, -1, msg, msglen) != 0) + if (proc_send(cf->peer, MSG_WRITE, -1, msg, msglen) != 0) break; evbuffer_drain(cf->buffer, sent); left = EVBUFFER_LENGTH(cf->buffer); - log_debug("%s: file %d sent %zu, left %zu", c->name, cf->stream, - sent, left); + log_debug("file %d sent %zu, left %zu", cf->stream, sent, left); } if (left != 0) { cf->references++; event_once(-1, EV_TIMEOUT, file_push_cb, cf, NULL); } else if (cf->stream > 2) { close.stream = cf->stream; - proc_send(c->peer, MSG_WRITE_CLOSE, -1, &close, sizeof close); + proc_send(cf->peer, MSG_WRITE_CLOSE, -1, &close, sizeof close); file_fire_done(cf); } free(msg); } + +/* Client file write error callback. */ +static void +file_write_error_callback(__unused struct bufferevent *bev, __unused short what, + void *arg) +{ + struct client_file *cf = arg; + + log_debug("write error file %d", cf->stream); + + if (cf->cb != NULL) + cf->cb(NULL, NULL, 0, -1, NULL, cf->data); + + bufferevent_free(cf->event); + cf->event = NULL; + + close(cf->fd); + cf->fd = -1; +} + +/* Client file write callback. */ +static void +file_write_callback(__unused struct bufferevent *bev, void *arg) +{ + struct client_file *cf = arg; + + log_debug("write check file %d", cf->stream); + + if (cf->cb != NULL) + cf->cb(NULL, NULL, 0, -1, NULL, cf->data); + + if (cf->closed && EVBUFFER_LENGTH(cf->event->output) == 0) { + bufferevent_free(cf->event); + close(cf->fd); + RB_REMOVE(client_files, cf->tree, cf); + file_free(cf); + } +} + +/* Handle a file write open message (client). */ +void +file_write_open(struct client_files *files, struct tmuxpeer *peer, + struct imsg *imsg, int allow_streams, int close_received, + client_file_cb cb, void *cbdata) +{ + struct msg_write_open *msg = imsg->data; + size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE; + const char *path; + struct msg_write_ready reply; + struct client_file find, *cf; + const int flags = O_NONBLOCK|O_WRONLY|O_CREAT; + int error = 0; + + if (msglen < sizeof *msg) + fatalx("bad MSG_WRITE_OPEN size"); + if (msglen == sizeof *msg) + path = "-"; + else + path = (const char *)(msg + 1); + log_debug("open write file %d %s", msg->stream, path); + + find.stream = msg->stream; + if ((cf = RB_FIND(client_files, files, &find)) != NULL) { + error = EBADF; + goto reply; + } + cf = file_create_with_peer(peer, files, msg->stream, cb, cbdata); + if (cf->closed) { + error = EBADF; + goto reply; + } + + cf->fd = -1; + if (msg->fd == -1) + cf->fd = open(path, msg->flags|flags, 0644); + else if (allow_streams) { + if (msg->fd != STDOUT_FILENO && msg->fd != STDERR_FILENO) + errno = EBADF; + else { + cf->fd = dup(msg->fd); + if (close_received) + close(msg->fd); /* can only be used once */ + } + } else + errno = EBADF; + if (cf->fd == -1) { + error = errno; + goto reply; + } + + cf->event = bufferevent_new(cf->fd, NULL, file_write_callback, + file_write_error_callback, cf); + bufferevent_enable(cf->event, EV_WRITE); + goto reply; + +reply: + reply.stream = msg->stream; + reply.error = error; + proc_send(peer, MSG_WRITE_READY, -1, &reply, sizeof reply); +} + +/* Handle a file write data message (client). */ +void +file_write_data(struct client_files *files, struct imsg *imsg) +{ + struct msg_write_data *msg = imsg->data; + size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE; + struct client_file find, *cf; + size_t size = msglen - sizeof *msg; + + if (msglen < sizeof *msg) + fatalx("bad MSG_WRITE size"); + find.stream = msg->stream; + if ((cf = RB_FIND(client_files, files, &find)) == NULL) + fatalx("unknown stream number"); + log_debug("write %zu to file %d", size, cf->stream); + + if (cf->event != NULL) + bufferevent_write(cf->event, msg + 1, size); +} + +/* Handle a file write close message (client). */ +void +file_write_close(struct client_files *files, struct imsg *imsg) +{ + struct msg_write_close *msg = imsg->data; + size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE; + struct client_file find, *cf; + + if (msglen != sizeof *msg) + fatalx("bad MSG_WRITE_CLOSE size"); + find.stream = msg->stream; + if ((cf = RB_FIND(client_files, files, &find)) == NULL) + fatalx("unknown stream number"); + log_debug("close file %d", cf->stream); + + if (cf->event == NULL || EVBUFFER_LENGTH(cf->event->output) == 0) { + if (cf->event != NULL) + bufferevent_free(cf->event); + if (cf->fd != -1) + close(cf->fd); + RB_REMOVE(client_files, files, cf); + file_free(cf); + } +} + +/* Client file read error callback. */ +static void +file_read_error_callback(__unused struct bufferevent *bev, __unused short what, + void *arg) +{ + struct client_file *cf = arg; + struct msg_read_done msg; + + log_debug("read error file %d", cf->stream); + + msg.stream = cf->stream; + msg.error = 0; + proc_send(cf->peer, MSG_READ_DONE, -1, &msg, sizeof msg); + + bufferevent_free(cf->event); + close(cf->fd); + RB_REMOVE(client_files, cf->tree, cf); + file_free(cf); +} + +/* Client file read callback. */ +static void +file_read_callback(__unused struct bufferevent *bev, void *arg) +{ + struct client_file *cf = arg; + void *bdata; + size_t bsize; + struct msg_read_data *msg; + size_t msglen; + + msg = xmalloc(sizeof *msg); + for (;;) { + bdata = EVBUFFER_DATA(cf->event->input); + bsize = EVBUFFER_LENGTH(cf->event->input); + + if (bsize == 0) + break; + if (bsize > MAX_IMSGSIZE - IMSG_HEADER_SIZE - sizeof *msg) + bsize = MAX_IMSGSIZE - IMSG_HEADER_SIZE - sizeof *msg; + log_debug("read %zu from file %d", bsize, cf->stream); + + msglen = (sizeof *msg) + bsize; + msg = xrealloc(msg, msglen); + msg->stream = cf->stream; + memcpy(msg + 1, bdata, bsize); + proc_send(cf->peer, MSG_READ, -1, msg, msglen); + + evbuffer_drain(cf->event->input, bsize); + } + free(msg); +} + +/* Handle a file read open message (client). */ +void +file_read_open(struct client_files *files, struct tmuxpeer *peer, + struct imsg *imsg, int allow_streams, int close_received, client_file_cb cb, + void *cbdata) +{ + struct msg_read_open *msg = imsg->data; + size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE; + const char *path; + struct msg_read_done reply; + struct client_file find, *cf; + const int flags = O_NONBLOCK|O_RDONLY; + int error; + + if (msglen < sizeof *msg) + fatalx("bad MSG_READ_OPEN size"); + if (msglen == sizeof *msg) + path = "-"; + else + path = (const char *)(msg + 1); + log_debug("open read file %d %s", msg->stream, path); + + find.stream = msg->stream; + if ((cf = RB_FIND(client_files, files, &find)) != NULL) { + error = EBADF; + goto reply; + } + cf = file_create_with_peer(peer, files, msg->stream, cb, cbdata); + if (cf->closed) { + error = EBADF; + goto reply; + } + + cf->fd = -1; + if (msg->fd == -1) + cf->fd = open(path, flags); + else if (allow_streams) { + if (msg->fd != STDIN_FILENO) + errno = EBADF; + else { + cf->fd = dup(msg->fd); + if (close_received) + close(msg->fd); /* can only be used once */ + } + } else + errno = EBADF; + if (cf->fd == -1) { + error = errno; + goto reply; + } + + cf->event = bufferevent_new(cf->fd, file_read_callback, NULL, + file_read_error_callback, cf); + bufferevent_enable(cf->event, EV_READ); + return; + +reply: + reply.stream = msg->stream; + reply.error = error; + proc_send(peer, MSG_READ_DONE, -1, &reply, sizeof reply); +} + +/* Handle a write ready message (server). */ +void +file_write_ready(struct client_files *files, struct imsg *imsg) +{ + struct msg_write_ready *msg = imsg->data; + size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE; + struct client_file find, *cf; + + if (msglen != sizeof *msg) + fatalx("bad MSG_WRITE_READY size"); + find.stream = msg->stream; + if ((cf = RB_FIND(client_files, files, &find)) == NULL) + return; + if (msg->error != 0) { + cf->error = msg->error; + file_fire_done(cf); + } else + file_push(cf); +} + +/* Handle read data message (server). */ +void +file_read_data(struct client_files *files, struct imsg *imsg) +{ + struct msg_read_data *msg = imsg->data; + size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE; + struct client_file find, *cf; + void *bdata = msg + 1; + size_t bsize = msglen - sizeof *msg; + + if (msglen < sizeof *msg) + fatalx("bad MSG_READ_DATA size"); + find.stream = msg->stream; + if ((cf = RB_FIND(client_files, files, &find)) == NULL) + return; + + log_debug("file %d read %zu bytes", cf->stream, bsize); + if (cf->error == 0) { + if (evbuffer_add(cf->buffer, bdata, bsize) != 0) { + cf->error = ENOMEM; + file_fire_done(cf); + } else + file_fire_read(cf); + } +} + +/* Handle a read done message (server). */ +void +file_read_done(struct client_files *files, struct imsg *imsg) +{ + struct msg_read_done *msg = imsg->data; + size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE; + struct client_file find, *cf; + + if (msglen != sizeof *msg) + fatalx("bad MSG_READ_DONE size"); + find.stream = msg->stream; + if ((cf = RB_FIND(client_files, files, &find)) == NULL) + return; + + log_debug("file %d read done", cf->stream); + cf->error = msg->error; + file_fire_done(cf); +} -- cgit v1.2.3