X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Futcp.c;h=1c0890c6743b4a71b4da052bdb7ee800958b71ad;hb=HEAD;hp=65e6be7a2de4e19ac42401ef2696a1590561435d;hpb=e40d5bf3a0e030105334046319f377efbf3f06c4;p=meshlink diff --git a/src/utcp.c b/src/utcp.c index 65e6be7a..ca91bee2 100644 --- a/src/utcp.c +++ b/src/utcp.c @@ -196,6 +196,16 @@ static bool buffer_wraps(struct buffer *buf) { } static bool buffer_resize(struct buffer *buf, uint32_t newsize) { + assert(!buf->external); + + if(!newsize) { + free(buf->data); + buf->data = NULL; + buf->size = 0; + buf->offset = 0; + return true; + } + char *newdata = realloc(buf->data, newsize); if(!newdata) { @@ -395,8 +405,99 @@ static bool buffer_set_size(struct buffer *buf, uint32_t minsize, uint32_t maxsi return buf->size >= minsize || buffer_resize(buf, minsize); } +static void buffer_transfer(struct buffer *buf, char *newdata, size_t newsize) { + if(buffer_wraps(buf)) { + // Old situation: + // [345......012] + // New situation: + // [012345......] + uint32_t tailsize = buf->size - buf->offset; + memcpy(newdata, buf->data + buf->offset, tailsize); + memcpy(newdata + tailsize, buf->data, buf->used - tailsize); + } else { + // Old situation: + // [....012345..] + // New situation: + // [012345......] + memcpy(newdata, buf->data + buf->offset, buf->used); + } + + buf->offset = 0; + buf->size = newsize; +} + +static void set_buffer_storage(struct buffer *buf, char *data, size_t size) { + if(size > UINT32_MAX) { + size = UINT32_MAX; + } + + buf->maxsize = size; + + if(data) { + if(buf->external) { + // Don't allow resizing an external buffer + abort(); + } + + if(size < buf->used) { + // Ignore requests for an external buffer if we are already using more than it can store + return; + } + + // Transition from internal to external buffer + buffer_transfer(buf, data, size); + free(buf->data); + buf->data = data; + buf->external = true; + } else if(buf->external) { + // Transition from external to internal buf + size_t minsize = buf->used <= DEFAULT_SNDBUFSIZE ? DEFAULT_SNDBUFSIZE : buf->used; + + if(minsize) { + data = malloc(minsize); + + if(!data) { + // Cannot handle this + abort(); + } + + buffer_transfer(buf, data, minsize); + buf->data = data; + } else { + buf->data = NULL; + buf->size = 0; + } + + buf->external = false; + } else { + // Don't do anything if the buffer wraps + if(buffer_wraps(buf)) { + return; + } + + // Realloc internal storage + size_t minsize = max(DEFAULT_SNDBUFSIZE, buf->offset + buf->used); + + if(minsize) { + data = realloc(buf->data, minsize); + + if(data) { + buf->data = data; + buf->size = minsize; + } + } else { + free(buf->data); + buf->data = NULL; + buf->size = 0; + } + } +} + static void buffer_exit(struct buffer *buf) { - free(buf->data); + if(!buf->external) { + free(buf->data); + } + memset(buf, 0, sizeof(*buf)); } @@ -1368,7 +1469,7 @@ synack: if(c->state == CLOSED) { debug(c, "got packet for closed connection\n"); - return 0; + goto reset; } // It is for an existing connection. @@ -1456,17 +1557,6 @@ synack: } } - if(hdr.ctl & ACK && (seqdiff(hdr.ack, c->snd.last) > 0 || seqdiff(hdr.ack, c->snd.una) < 0)) { - debug(c, "packet ack seqno out of range, %u <= %u < %u\n", c->snd.una, hdr.ack, c->snd.una + c->sndbuf.used); - - // Ignore unacceptable RST packets. - if(hdr.ctl & RST) { - return 0; - } - - goto reset; - } - // 2. Handle RST packets if(hdr.ctl & RST) { @@ -1510,6 +1600,8 @@ synack: // The peer has aborted our connection. set_state(c, CLOSED); errno = ECONNRESET; + buffer_clear(&c->sndbuf); + buffer_clear(&c->rcvbuf); if(c->recv) { c->recv(c, NULL, 0); @@ -1556,6 +1648,11 @@ synack: // 3. Advance snd.una + if(seqdiff(hdr.ack, c->snd.last) > 0 || seqdiff(hdr.ack, c->snd.una) < 0) { + debug(c, "packet ack seqno out of range, %u <= %u < %u\n", c->snd.una, hdr.ack, c->snd.una + c->sndbuf.used); + goto reset; + } + advanced = seqdiff(hdr.ack, c->snd.una); if(advanced) { @@ -1778,8 +1875,15 @@ skip_ack: return 0; case ESTABLISHED: + break; + case FIN_WAIT_1: case FIN_WAIT_2: + if(c->reapable) { + // We already closed the connection and are not interested in more data. + goto reset; + } + break; case CLOSE_WAIT: @@ -1970,8 +2074,8 @@ static bool reset_connection(struct utcp_connection *c) { return false; } - c->recv = NULL; - c->poll = NULL; + buffer_clear(&c->sndbuf); + buffer_clear(&c->rcvbuf); switch(c->state) { case CLOSED: @@ -2001,17 +2105,27 @@ static bool reset_connection(struct utcp_connection *c) { hdr.src = c->src; hdr.dst = c->dst; hdr.seq = c->snd.nxt; - hdr.ack = 0; + hdr.ack = c->rcv.nxt; hdr.wnd = 0; hdr.ctl = RST; + hdr.aux = 0; print_packet(c, "send", &hdr, sizeof(hdr)); c->utcp->send(c->utcp, &hdr, sizeof(hdr)); return true; } -// Closes all the opened connections -void utcp_abort_all_connections(struct utcp *utcp) { +static void set_reapable(struct utcp_connection *c) { + set_buffer_storage(&c->sndbuf, NULL, min(c->sndbuf.maxsize, DEFAULT_MAXSNDBUFSIZE)); + set_buffer_storage(&c->rcvbuf, NULL, min(c->rcvbuf.maxsize, DEFAULT_MAXRCVBUFSIZE)); + + c->recv = NULL; + c->poll = NULL; + c->reapable = true; +} + +// Resets all connections, but does not invalidate connection handles +void utcp_reset_all_connections(struct utcp *utcp) { if(!utcp) { errno = EINVAL; return; @@ -2024,19 +2138,16 @@ void utcp_abort_all_connections(struct utcp *utcp) { continue; } - utcp_recv_t old_recv = c->recv; - utcp_poll_t old_poll = c->poll; - reset_connection(c); - if(old_recv) { + if(c->recv) { errno = 0; - old_recv(c, NULL, 0); + c->recv(c, NULL, 0); } - if(old_poll && !c->reapable) { + if(c->poll && !c->reapable) { errno = 0; - old_poll(c, 0); + c->poll(c, 0); } } @@ -2044,17 +2155,11 @@ void utcp_abort_all_connections(struct utcp *utcp) { } int utcp_close(struct utcp_connection *c) { - if(c->rcvbuf.used) { - return reset_connection(c) ? 0 : -1; - } - if(utcp_shutdown(c, SHUT_RDWR) && errno != ENOTCONN) { return -1; } - c->recv = NULL; - c->poll = NULL; - c->reapable = true; + set_reapable(c); return 0; } @@ -2063,7 +2168,7 @@ int utcp_abort(struct utcp_connection *c) { return -1; } - c->reapable = true; + set_reapable(c); return 0; } @@ -2099,6 +2204,8 @@ struct timespec utcp_timeout(struct utcp *utcp) { if(timespec_isset(&c->conn_timeout) && timespec_lt(&c->conn_timeout, &now)) { errno = ETIMEDOUT; c->state = CLOSED; + buffer_clear(&c->sndbuf); + buffer_clear(&c->rcvbuf); if(c->recv) { c->recv(c, NULL, 0); @@ -2201,6 +2308,9 @@ void utcp_exit(struct utcp *utcp) { struct utcp_connection *c = utcp->connections[i]; if(!c->reapable) { + buffer_clear(&c->sndbuf); + buffer_clear(&c->rcvbuf); + if(c->recv) { c->recv(c, NULL, 0); } @@ -2318,16 +2428,12 @@ size_t utcp_get_sndbuf_free(struct utcp_connection *c) { } } -void utcp_set_sndbuf(struct utcp_connection *c, size_t size) { +void utcp_set_sndbuf(struct utcp_connection *c, void *data, size_t size) { if(!c) { return; } - c->sndbuf.maxsize = size; - - if(c->sndbuf.maxsize != size) { - c->sndbuf.maxsize = -1; - } + set_buffer_storage(&c->sndbuf, data, size); c->do_poll = is_reliable(c) && buffer_free(&c->sndbuf); } @@ -2344,16 +2450,12 @@ size_t utcp_get_rcvbuf_free(struct utcp_connection *c) { } } -void utcp_set_rcvbuf(struct utcp_connection *c, size_t size) { +void utcp_set_rcvbuf(struct utcp_connection *c, void *data, size_t size) { if(!c) { return; } - c->rcvbuf.maxsize = size; - - if(c->rcvbuf.maxsize != size) { - c->rcvbuf.maxsize = -1; - } + set_buffer_storage(&c->rcvbuf, data, size); } size_t utcp_get_sendq(struct utcp_connection *c) { @@ -2431,6 +2533,11 @@ void utcp_expect_data(struct utcp_connection *c, bool expect) { } } +void utcp_set_flags(struct utcp_connection *c, uint32_t flags) { + c->flags &= ~UTCP_CHANGEABLE_FLAGS; + c->flags |= flags & UTCP_CHANGEABLE_FLAGS; +} + void utcp_offline(struct utcp *utcp, bool offline) { struct timespec now; clock_gettime(UTCP_CLOCK, &now);