X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=utcp.c;h=0cb68b9da7195495602c1c196c835f2cab46d7b2;hb=8df47165e536daa4ff37e657476850ac94dafc69;hp=89a38b7d1c9546e94458531031b2ea419dad9cd6;hpb=1ba5f4c56c38b3c986dabb5d0feced74d81cd490;p=utcp diff --git a/utcp.c b/utcp.c index 89a38b7..0cb68b9 100644 --- a/utcp.c +++ b/utcp.c @@ -49,13 +49,13 @@ (r)->tv_sec = (a)->tv_sec - (b)->tv_sec;\ (r)->tv_usec = (a)->tv_usec - (b)->tv_usec;\ if((r)->tv_usec < 0)\ - (r)->tv_sec--, (r)->tv_usec += 1000000;\ + (r)->tv_sec--, (r)->tv_usec += USEC_PER_SEC;\ } while (0) #endif -#ifndef max -#define max(a, b) ((a) > (b) ? (a) : (b)) -#endif +static inline size_t max(size_t a, size_t b) { + return a > b ? a : b; +} #ifdef UTCP_DEBUG #include @@ -70,12 +70,12 @@ static void debug(const char *format, ...) { static void print_packet(struct utcp *utcp, const char *dir, const void *pkt, size_t len) { struct hdr hdr; if(len < sizeof hdr) { - debug("%p %s: short packet (%zu bytes)\n", utcp, dir, len); + debug("%p %s: short packet (%lu bytes)\n", utcp, dir, (unsigned long)len); return; } memcpy(&hdr, pkt, sizeof hdr); - fprintf (stderr, "%p %s: len=%zu, src=%u dst=%u seq=%u ack=%u wnd=%u ctl=", utcp, dir, len, hdr.src, hdr.dst, hdr.seq, hdr.ack, hdr.wnd); + debug("%p %s: len=%lu, src=%u dst=%u seq=%u ack=%u wnd=%u ctl=", utcp, dir, (unsigned long)len, hdr.src, hdr.dst, hdr.seq, hdr.ack, hdr.wnd); if(hdr.ctl & SYN) debug("SYN"); if(hdr.ctl & RST) @@ -87,23 +87,17 @@ static void print_packet(struct utcp *utcp, const char *dir, const void *pkt, si if(len > sizeof hdr) { uint32_t datalen = len - sizeof hdr; - uint8_t *str = malloc((datalen << 1) + 7); - memcpy(str, " data=", 6); - uint8_t *strptr = str + 6; - const uint8_t *data = pkt; - const uint8_t *dataend = data + datalen; - - while(data != dataend) { - *strptr = (*data >> 4) > 9? (*data >> 4) + 55 : (*data >> 4) + 48; - ++strptr; - *strptr = (*data & 0xf) > 9? (*data & 0xf) + 55 : (*data & 0xf) + 48; - ++strptr; - ++data; + const uint8_t *data = (uint8_t *)pkt + sizeof hdr; + char str[datalen * 2 + 1]; + char *p = str; + + for(uint32_t i = 0; i < datalen; i++) { + *p++ = "0123456789ABCDEF"[data[i] >> 4]; + *p++ = "0123456789ABCDEF"[data[i] & 15]; } - *strptr = 0; + *p = 0; - debug(str); - free(str); + debug(" data=%s", str); } debug("\n"); @@ -148,16 +142,12 @@ static int32_t seqdiff(uint32_t a, uint32_t b) { // Store data into the buffer static ssize_t buffer_put_at(struct buffer *buf, size_t offset, const void *data, size_t len) { - if(buf->maxsize <= buf->used) - return 0; - - debug("buffer_put_at %zu %zu %zu\n", buf->used, offset, len); + debug("buffer_put_at %lu %lu %lu\n", (unsigned long)buf->used, (unsigned long)offset, (unsigned long)len); size_t required = offset + len; if(required > buf->maxsize) { if(offset >= buf->maxsize) return 0; - abort(); len = buf->maxsize - offset; required = buf->maxsize; } @@ -169,7 +159,7 @@ static ssize_t buffer_put_at(struct buffer *buf, size_t offset, const void *data } else { do { newsize *= 2; - } while(newsize < buf->used + len); + } while(newsize < required); } if(newsize > buf->maxsize) newsize = buf->maxsize; @@ -547,8 +537,11 @@ static void swap_ports(struct hdr *hdr) { } static void retransmit(struct utcp_connection *c) { - if(c->state == CLOSED || c->snd.nxt == c->snd.una) + if(c->state == CLOSED || c->snd.last == c->snd.una) { + debug("Retransmit() called but nothing to retransmit!\n"); + stop_retransmit_timer(c); return; + } struct utcp *utcp = c->utcp; @@ -630,11 +623,31 @@ cleanup: free(pkt); } -// Update receive buffer and SACK entries after consuming data. +/* Update receive buffer and SACK entries after consuming data. + * + * Situation: + * + * |.....0000..1111111111.....22222......3333| + * |---------------^ + * + * 0..3 represent the SACK entries. The ^ indicates up to which point we want + * to remove data from the receive buffer. The idea is to substract "len" + * from the offset of all the SACK entries, and then remove/cut down entries + * that are shifted to before the start of the receive buffer. + * + * There are three cases: + * - the SACK entry is after ^, in that case just change the offset. + * - the SACK entry starts before and ends after ^, so we have to + * change both its offset and size. + * - the SACK entry is completely before ^, in that case delete it. + */ static void sack_consume(struct utcp_connection *c, size_t len) { - debug("sack_consume %zu\n", len); - if(len > c->rcvbuf.used) - abort(); + debug("sack_consume %lu\n", (unsigned long)len); + if(len > c->rcvbuf.used) { + debug("All SACK entries consumed"); + c->sacks[0].len = 0; + return; + } buffer_get(&c->rcvbuf, NULL, len); @@ -643,13 +656,13 @@ static void sack_consume(struct utcp_connection *c, size_t len) { c->sacks[i].offset -= len; i++; } else if(len < c->sacks[i].offset + c->sacks[i].len) { - c->sacks[i].offset = 0; c->sacks[i].len -= len - c->sacks[i].offset; + c->sacks[i].offset = 0; i++; } else { if(i < NSACKS - 1) { memmove(&c->sacks[i], &c->sacks[i + 1], (NSACKS - 1 - i) * sizeof c->sacks[i]); - c->sacks[i + 1].len = 0; + c->sacks[NSACKS - 1].len = 0; } else { c->sacks[i].len = 0; break; @@ -682,6 +695,8 @@ static void handle_out_of_order(struct utcp_connection *c, uint32_t offset, cons memmove(&c->sacks[i + 1], &c->sacks[i], (NSACKS - i - 1) * sizeof c->sacks[i]); c->sacks[i].offset = offset; c->sacks[i].len = rxd; + } else { + debug("SACK entries full, dropping packet\n"); } break; } else { // merge @@ -706,7 +721,7 @@ static void handle_out_of_order(struct utcp_connection *c, uint32_t offset, cons static void handle_in_order(struct utcp_connection *c, const void *data, size_t len) { // Check if we can process out-of-order data now. if(c->sacks[0].len && len >= c->sacks[0].offset) { // TODO: handle overlap with second SACK - debug("incoming packet len %zu connected with SACK at %u\n", len, c->sacks[0].offset); + debug("incoming packet len %lu connected with SACK at %u\n", (unsigned long)len, c->sacks[0].offset); buffer_put_at(&c->rcvbuf, 0, data, len); // TODO: handle return value len = max(len, c->sacks[0].offset + c->sacks[0].len); data = c->rcvbuf.data; @@ -831,8 +846,10 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) { // In case this is for a CLOSED connection, ignore the packet. // TODO: make it so incoming packets can never match a CLOSED connection. - if(c->state == CLOSED) + if(c->state == CLOSED) { + debug("Got packet for closed connection\n"); return 0; + } // It is for an existing connection. @@ -873,24 +890,24 @@ ssize_t utcp_recv(struct utcp *utcp, const void *data, size_t len) { // cut already accepted front overlapping if(rcv_offset < 0) { - acceptable = rcv_offset + len >= 0; + acceptable = len > -rcv_offset; if(acceptable) { data -= rcv_offset; len += rcv_offset; + hdr.seq -= rcv_offset; } + } else { + acceptable = seqdiff(hdr.seq, c->rcv.nxt) >= 0 && seqdiff(hdr.seq, c->rcv.nxt) + len <= c->rcvbuf.maxsize; } - - acceptable = seqdiff(hdr.seq, c->rcv.nxt) >= 0 && seqdiff(hdr.seq, c->rcv.nxt) + len <= c->rcvbuf.maxsize; } if(!acceptable) { - debug("Packet not acceptable, %u <= %u + %zu < %u\n", c->rcv.nxt, hdr.seq, len, c->rcv.nxt + c->rcvbuf.maxsize); + debug("Packet not acceptable, %u <= %u + %lu < %u\n", c->rcv.nxt, hdr.seq, (unsigned long)len, c->rcv.nxt + c->rcvbuf.maxsize); // Ignore unacceptable RST packets. if(hdr.ctl & RST) return 0; - // Otherwise, send an ACK back in the hope things improve. - ack(c, true); - return 0; + // Otherwise, continue processing. + len = 0; } c->snd.wnd = hdr.wnd; // TODO: move below @@ -1268,7 +1285,7 @@ int utcp_shutdown(struct utcp_connection *c, int dir) { } int utcp_close(struct utcp_connection *c) { - if(utcp_shutdown(c, SHUT_RDWR)) + if(utcp_shutdown(c, SHUT_RDWR) && errno != ENOTCONN) return -1; c->recv = NULL; c->poll = NULL; @@ -1408,8 +1425,8 @@ struct utcp *utcp_init(utcp_accept_t accept, utcp_pre_accept_t pre_accept, utcp_ utcp->send = send; utcp->priv = priv; utcp->mtu = DEFAULT_MTU; - utcp->timeout = DEFAULT_USER_TIMEOUT; // s - utcp->rto = START_RTO; // us + utcp->timeout = DEFAULT_USER_TIMEOUT; // sec + utcp->rto = START_RTO; // usec return utcp; }