diff options
| -rw-r--r-- | common-channel.c | 200 | ||||
| -rw-r--r-- | debug.h | 2 |
2 files changed, 87 insertions, 115 deletions
diff --git a/common-channel.c b/common-channel.c index a6e3364..e8175ae 100644 --- a/common-channel.c +++ b/common-channel.c @@ -43,17 +43,14 @@ static void send_msg_channel_open_confirmation(struct Channel* channel, static void writechannel(struct Channel* channel, int fd, circbuffer *cbuf); static void send_msg_channel_window_adjust(struct Channel *channel, unsigned int incr); -static void send_msg_channel_data(struct Channel *channel, int isextended, - unsigned int exttype); +static void send_msg_channel_data(struct Channel *channel, int isextended); static void send_msg_channel_eof(struct Channel *channel); static void send_msg_channel_close(struct Channel *channel); static void remove_channel(struct Channel *channel); static void delete_channel(struct Channel *channel); static void check_in_progress(struct Channel *channel); +static unsigned int write_pending(struct Channel * channel); static void check_close(struct Channel *channel); - -static void close_write_fd(struct Channel * channel); -static void close_read_fd(struct Channel * channel, int fd); static void close_chan_fd(struct Channel *channel, int fd, int how); #define FD_UNINIT (-2) @@ -192,7 +189,7 @@ void channelio(fd_set *readfds, fd_set *writefds) { struct Channel *channel; unsigned int i; - /* iterate through all the possible channels */ + /* foreach channel */ for (i = 0; i < ses.chansize; i++) { channel = ses.channels[i]; @@ -203,31 +200,19 @@ void channelio(fd_set *readfds, fd_set *writefds) { /* read data and send it over the wire */ if (channel->readfd >= 0 && FD_ISSET(channel->readfd, readfds)) { - send_msg_channel_data(channel, 0, 0); + send_msg_channel_data(channel, 0); } /* read stderr data and send it over the wire */ if (channel->extrabuf == NULL && channel->errfd >= 0 && FD_ISSET(channel->errfd, readfds)) { - send_msg_channel_data(channel, 1, SSH_EXTENDED_DATA_STDERR); + send_msg_channel_data(channel, 1); } -#if 0 - /* XXX where is this required? */ - if (channel->initconn) { - /* Handling for "in progress" connection - this is needed - * to avoid spinning 100% CPU when we connect to a server - * which doesn't send anything (tcpfwding) */ - check_in_progress(channel); - continue; /* Important not to use the channel after - check_in_progress(), as it may be NULL */ - } -#endif - /* write to program/pipe stdin */ if (channel->writefd >= 0 && FD_ISSET(channel->writefd, writefds)) { if (channel->initconn) { - /* XXX could this go somewhere cleaner? */ + /* XXX should this go somewhere cleaner? */ check_in_progress(channel); continue; /* Important not to use the channel after check_in_progress(), as it may be NULL */ @@ -241,10 +226,10 @@ void channelio(fd_set *readfds, fd_set *writefds) { writechannel(channel, channel->errfd, channel->extrabuf); } - /* now handle any of the channel-closing type stuff */ + /* handle any channel closing etc */ check_close(channel); - } /* foreach channel */ + } /* Listeners such as TCP, X11, agent-auth */ #ifdef USING_LISTENERS @@ -253,6 +238,20 @@ void channelio(fd_set *readfds, fd_set *writefds) { } +/* Returns true if there is data remaining to be written to stdin or + * stderr of a channel's endpoint. */ +static unsigned int write_pending(struct Channel * channel) { + + if (channel->writefd >= 0 && cbuf_getused(channel->writebuf) > 0) { + return 1; + } else if (channel->errfd >= 0 && channel->extrabuf && + cbuf_getused(channel->writebuf) > 0) { + return 1; + } + return 0; +} + + /* EOF/close handling */ static void check_close(struct Channel *channel) { @@ -264,8 +263,13 @@ static void check_close(struct Channel *channel) { channel->writebuf, channel->writebuf ? 0 : cbuf_getused(channel->extrabuf))) - /* XXX not good, doesn't flush out */ - if (channel->recv_close) { + if (!channel->sent_close + && channel->writefd == FD_CLOSED + && (channel->errfd == FD_CLOSED || channel->extrabuf == NULL)) { + send_msg_channel_close(channel); + } + + if (channel->recv_close && !write_pending(channel)) { if (! channel->sent_close) { TRACE(("Sending MSG_CHANNEL_CLOSE in response to same.")) send_msg_channel_close(channel); @@ -274,8 +278,10 @@ static void check_close(struct Channel *channel) { return; } - /* server chansession channels are special, since readfd mightn't - * close in the case of "sleep 4 & echo blah" until the sleep is up */ +#if 0 + // The only use of check_close is "return channel->writefd == -1;" for a server + // chansession. Should be able to handle that with just the general + // socket close handling...? if (channel->type->check_close) { if (channel->type->check_close(channel)) { close_write_fd(channel); @@ -283,6 +289,7 @@ static void check_close(struct Channel *channel) { close_read_fd(channel, channel->errfd); } } +#endif if (!channel->sent_eof && channel->readfd == FD_CLOSED @@ -296,25 +303,6 @@ static void check_close(struct Channel *channel) { && (channel->extrabuf != NULL || channel->errfd == FD_CLOSED)) { send_msg_channel_close(channel); } - - /* XXX blah */ - if (channel->recv_eof && - (cbuf_getused(channel->writebuf) == 0 - && (channel->extrabuf == NULL - || cbuf_getused(channel->extrabuf) == 0))) { - close_write_fd(channel); - } - - /* When either party wishes to terminate the channel, it sends - * SSH_MSG_CHANNEL_CLOSE. Upon receiving this message, a party MUST - * send back a SSH_MSG_CHANNEL_CLOSE unless it has already sent this - * message for the channel. The channel is considered closed for a - * party when it has both sent and received SSH_MSG_CHANNEL_CLOSE, and - * the party may then reuse the channel number. A party MAY send - * SSH_MSG_CHANNEL_CLOSE without having sent or received - * SSH_MSG_CHANNEL_EOF. - * (from draft-ietf-secsh-connect) - */ } @@ -398,9 +386,7 @@ static void writechannel(struct Channel* channel, int fd, circbuffer *cbuf) { len = write(fd, cbuf_readptr(cbuf, maxlen), maxlen); if (len <= 0) { if (len < 0 && errno != EINTR) { - /* no more to write - we close it even if the fd was stderr, since - * that's a nasty failure too */ - close_write_fd(channel); + close_chan_fd(channel, fd, SHUT_WR); } TRACE(("leave writechannel: len <= 0")) return; @@ -409,6 +395,13 @@ static void writechannel(struct Channel* channel, int fd, circbuffer *cbuf) { cbuf_incrread(cbuf, len); channel->recvdonelen += len; + /* We're closing out */ + if (channel->recv_eof && cbuf_getused(cbuf) == 0) { + TRACE(("leave writechannel")) + close_chan_fd(channel, fd, SHUT_WR); + return; + } + /* Window adjust handling */ if (channel->recvdonelen >= RECV_WINDOWEXTEND) { /* Set it back to max window */ @@ -572,16 +565,12 @@ void recv_msg_channel_request() { * chan is the remote channel, isextended is 0 if it is normal data, 1 * if it is extended data. if it is extended, then the type is in * exttype */ -static void send_msg_channel_data(struct Channel *channel, int isextended, - unsigned int exttype) { +static void send_msg_channel_data(struct Channel *channel, int isextended) { int len; size_t maxlen, size_pos; int fd; -/* TRACE(("enter send_msg_channel_data")) - TRACE(("extended = %d type = %d", isextended, exttype))*/ - CHECKCLEARTOWRITE(); dropbear_assert(!channel->sent_close); @@ -608,7 +597,7 @@ static void send_msg_channel_data(struct Channel *channel, int isextended, isextended ? SSH_MSG_CHANNEL_EXTENDED_DATA : SSH_MSG_CHANNEL_DATA); buf_putint(ses.writepayload, channel->remotechan); if (isextended) { - buf_putint(ses.writepayload, exttype); + buf_putint(ses.writepayload, SSH_EXTENDED_DATA_STDERR); } /* a dummy size first ...*/ size_pos = ses.writepayload->pos; @@ -618,7 +607,7 @@ static void send_msg_channel_data(struct Channel *channel, int isextended, len = read(fd, buf_getwriteptr(ses.writepayload, maxlen), maxlen); if (len <= 0) { if (len == 0 || errno != EINTR) { - close_read_fd(channel, fd); + close_chan_fd(channel, fd, SHUT_RD); } ses.writepayload->len = ses.writepayload->pos = 0; TRACE(("leave send_msg_channel_data: read err or EOF for fd %d", @@ -891,6 +880,47 @@ static void send_msg_channel_open_confirmation(struct Channel* channel, TRACE(("leave send_msg_channel_open_confirmation")) } +/* close a fd, how is SHUT_RD or SHUT_WR */ +static void close_chan_fd(struct Channel *channel, int fd, int how) { + + int closein = 0, closeout = 0; + + if (channel->type->sepfds) { + TRACE(("shutdown((%d), %d)", fd, how)) + shutdown(fd, how); + if (how == 0) { + closeout = 1; + } else { + closein = 1; + } + } else { + close(fd); + closein = closeout = 1; + } + + if (closeout && fd == channel->readfd) { + channel->readfd = FD_CLOSED; + } + if (closeout && (channel->extrabuf == NULL) && (fd == channel->errfd)) { + channel->errfd = FD_CLOSED; + } + + if (closein && fd == channel->writefd) { + channel->writefd = FD_CLOSED; + } + if (closein && (channel->extrabuf != NULL) && (fd == channel->errfd)) { + channel->errfd = FD_CLOSED; + } + + /* if we called shutdown on it and all references are gone, then we + * need to close() it to stop it lingering */ + if (channel->type->sepfds && channel->readfd == FD_CLOSED + && channel->writefd == FD_CLOSED && channel->errfd == FD_CLOSED) { + close(fd); + } +} + + #if defined(USING_LISTENERS) || defined(DROPBEAR_CLIENT) /* Create a new channel, and start the open request. This is intended * for X11, agent, tcp forwarding, and should be filled with channel-specific @@ -980,61 +1010,3 @@ void recv_msg_channel_open_failure() { remove_channel(channel); } #endif /* USING_LISTENERS */ - -/* close a stdout/stderr fd */ -static void close_read_fd(struct Channel * channel, int fd) { - - /* don't close it if it is the same as writefd, - * unless writefd is already set -1 */ - TRACE(("enter close_read_fd")) - close_chan_fd(channel, fd, 0); - TRACE(("leave close_read_fd")) -} - -/* close a stdin fd */ -static void close_write_fd(struct Channel * channel) { - - TRACE(("enter close_write_fd")) - close_chan_fd(channel, channel->writefd, 1); - TRACE(("leave close_write_fd")) -} - -/* close a fd, how is 0 for stdout/stderr, 1 for stdin */ -static void close_chan_fd(struct Channel *channel, int fd, int how) { - - int closein = 0, closeout = 0; - - if (channel->type->sepfds) { - TRACE(("shutdown((%d), %d)", fd, how)) - shutdown(fd, how); - if (how == 0) { - closeout = 1; - } else { - closein = 1; - } - } else { - close(fd); - closein = closeout = 1; - } - - if (closeout && fd == channel->readfd) { - channel->readfd = FD_CLOSED; - } - if (closeout && (channel->extrabuf == NULL) && (fd == channel->errfd)) { - channel->errfd = FD_CLOSED; - } - - if (closein && fd == channel->writefd) { - channel->writefd = FD_CLOSED; - } - if (closein && (channel->extrabuf != NULL) && (fd == channel->errfd)) { - channel->errfd = FD_CLOSED; - } - - /* if we called shutdown on it and all references are gone, then we - * need to close() it to stop it lingering */ - if (channel->type->sepfds && channel->readfd == FD_CLOSED - && channel->writefd == FD_CLOSED && channel->errfd == FD_CLOSED) { - close(fd); - } -} @@ -39,7 +39,7 @@ * Caution: Don't use this in an unfriendly environment (ie unfirewalled), * since the printing may not sanitise strings etc. This will add a reasonable * amount to your executable size. */ -/*#define DEBUG_TRACE */ +#define DEBUG_TRACE /* All functions writing to the cleartext payload buffer call * CHECKCLEARTOWRITE() before writing. This is only really useful if you're |