diff options
Diffstat (limited to 'core/lwip/src/core/tcp_out.c')
| -rw-r--r-- | core/lwip/src/core/tcp_out.c | 1066 |
1 files changed, 740 insertions, 326 deletions
diff --git a/core/lwip/src/core/tcp_out.c b/core/lwip/src/core/tcp_out.c index ddada420..86e09195 100644 --- a/core/lwip/src/core/tcp_out.c +++ b/core/lwip/src/core/tcp_out.c @@ -42,382 +42,643 @@ #if LWIP_TCP /* don't build if not configured for use in lwipopts.h */ -#include "lwip/tcp.h" +#include "lwip/tcp_impl.h" #include "lwip/def.h" #include "lwip/mem.h" #include "lwip/memp.h" #include "lwip/sys.h" #include "lwip/ip_addr.h" #include "lwip/netif.h" -#include "lwip/inet.h" #include "lwip/inet_chksum.h" #include "lwip/stats.h" #include "lwip/snmp.h" #include <string.h> +/* Define some copy-macros for checksum-on-copy so that the code looks + nicer by preventing too many ifdef's. */ +#if TCP_CHECKSUM_ON_COPY +#define TCP_DATA_COPY(dst, src, len, seg) do { \ + tcp_seg_add_chksum(LWIP_CHKSUM_COPY(dst, src, len), \ + len, &seg->chksum, &seg->chksum_swapped); \ + seg->flags |= TF_SEG_DATA_CHECKSUMMED; } while(0) +#define TCP_DATA_COPY2(dst, src, len, chksum, chksum_swapped) \ + tcp_seg_add_chksum(LWIP_CHKSUM_COPY(dst, src, len), len, chksum, chksum_swapped); +#else /* TCP_CHECKSUM_ON_COPY*/ +#define TCP_DATA_COPY(dst, src, len, seg) MEMCPY(dst, src, len) +#define TCP_DATA_COPY2(dst, src, len, chksum, chksum_swapped) MEMCPY(dst, src, len) +#endif /* TCP_CHECKSUM_ON_COPY*/ + +/** Define this to 1 for an extra check that the output checksum is valid + * (usefule when the checksum is generated by the application, not the stack) */ +#ifndef TCP_CHECKSUM_ON_COPY_SANITY_CHECK +#define TCP_CHECKSUM_ON_COPY_SANITY_CHECK 0 +#endif + /* Forward declarations.*/ static void tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb); -static struct tcp_hdr * -tcp_output_set_header(struct tcp_pcb *pcb, struct pbuf *p, int optlen, +/** Allocate a pbuf and create a tcphdr at p->payload, used for output + * functions other than the default tcp_output -> tcp_output_segment + * (e.g. tcp_send_empty_ack, etc.) + * + * @param pcb tcp pcb for which to send a packet (used to initialize tcp_hdr) + * @param optlen length of header-options + * @param datalen length of tcp data to reserve in pbuf + * @param seqno_be seqno in network byte order (big-endian) + * @return pbuf with p->payload being the tcp_hdr + */ +static struct pbuf * +tcp_output_alloc_header(struct tcp_pcb *pcb, u16_t optlen, u16_t datalen, u32_t seqno_be /* already in network byte order */) { - struct tcp_hdr *tcphdr = p->payload; - tcphdr->src = htons(pcb->local_port); - tcphdr->dest = htons(pcb->remote_port); - tcphdr->seqno = seqno_be; - tcphdr->ackno = htonl(pcb->rcv_nxt); - TCPH_FLAGS_SET(tcphdr, TCP_ACK); - tcphdr->wnd = htons(pcb->rcv_ann_wnd); - tcphdr->urgp = 0; - TCPH_HDRLEN_SET(tcphdr, (5 + optlen / 4)); - tcphdr->chksum = 0; - - /* If we're sending a packet, update the announced right window edge */ - pcb->rcv_ann_right_edge = pcb->rcv_nxt + pcb->rcv_ann_wnd; - - return tcphdr; + struct tcp_hdr *tcphdr; + struct pbuf *p = pbuf_alloc(PBUF_IP, TCP_HLEN + optlen + datalen, PBUF_RAM); + if (p != NULL) { + LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr", + (p->len >= TCP_HLEN + optlen)); + tcphdr = (struct tcp_hdr *)p->payload; + tcphdr->src = htons(pcb->local_port); + tcphdr->dest = htons(pcb->remote_port); + tcphdr->seqno = seqno_be; + tcphdr->ackno = htonl(pcb->rcv_nxt); + TCPH_HDRLEN_FLAGS_SET(tcphdr, (5 + optlen / 4), TCP_ACK); + tcphdr->wnd = htons(pcb->rcv_ann_wnd); + tcphdr->chksum = 0; + tcphdr->urgp = 0; + + /* If we're sending a packet, update the announced right window edge */ + pcb->rcv_ann_right_edge = pcb->rcv_nxt + pcb->rcv_ann_wnd; + } + return p; } /** - * Called by tcp_close() to send a segment including flags but not data. + * Called by tcp_close() to send a segment including FIN flag but not data. * * @param pcb the tcp_pcb over which to send a segment - * @param flags the flags to set in the segment header * @return ERR_OK if sent, another err_t otherwise */ err_t -tcp_send_ctrl(struct tcp_pcb *pcb, u8_t flags) +tcp_send_fin(struct tcp_pcb *pcb) { + /* first, try to add the fin to the last unsent segment */ + if (pcb->unsent != NULL) { + struct tcp_seg *last_unsent; + for (last_unsent = pcb->unsent; last_unsent->next != NULL; + last_unsent = last_unsent->next); + + if ((TCPH_FLAGS(last_unsent->tcphdr) & (TCP_SYN | TCP_FIN | TCP_RST)) == 0) { + /* no SYN/FIN/RST flag in the header, we can add the FIN flag */ + TCPH_SET_FLAG(last_unsent->tcphdr, TCP_FIN); + return ERR_OK; + } + } /* no data, no length, flags, copy=1, no optdata */ - return tcp_enqueue(pcb, NULL, 0, flags, TCP_WRITE_FLAG_COPY, 0); + return tcp_enqueue_flags(pcb, TCP_FIN); } /** - * Write data for sending (but does not send it immediately). + * Create a TCP segment with prefilled header. * - * It waits in the expectation of more data being sent soon (as - * it can send them more efficiently by combining them together). - * To prompt the system to send data now, call tcp_output() after - * calling tcp_write(). - * - * @param pcb Protocol control block of the TCP connection to enqueue data for. - * @param data pointer to the data to send - * @param len length (in bytes) of the data to send - * @param apiflags combination of following flags : - * - TCP_WRITE_FLAG_COPY (0x01) data will be copied into memory belonging to the stack - * - TCP_WRITE_FLAG_MORE (0x02) for TCP connection, PSH flag will be set on last segment sent, - * @return ERR_OK if enqueued, another err_t on error - * - * @see tcp_write() + * Called by tcp_write and tcp_enqueue_flags. + * + * @param pcb Protocol control block for the TCP connection. + * @param p pbuf that is used to hold the TCP header. + * @param flags TCP flags for header. + * @param seqno TCP sequence number of this packet + * @param optflags options to include in TCP header + * @return a new tcp_seg pointing to p, or NULL. + * The TCP header is filled in except ackno and wnd. + * p is freed on failure. */ -err_t -tcp_write(struct tcp_pcb *pcb, const void *data, u16_t len, u8_t apiflags) +static struct tcp_seg * +tcp_create_segment(struct tcp_pcb *pcb, struct pbuf *p, u8_t flags, u32_t seqno, u8_t optflags) { - LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_write(pcb=%p, data=%p, len=%"U16_F", apiflags=%"U16_F")\n", (void *)pcb, - data, len, (u16_t)apiflags)); - /* connection is in valid state for data transmission? */ - if (pcb->state == ESTABLISHED || - pcb->state == CLOSE_WAIT || - pcb->state == SYN_SENT || - pcb->state == SYN_RCVD) { - if (len > 0) { -#if LWIP_TCP_TIMESTAMPS - return tcp_enqueue(pcb, (void *)data, len, 0, apiflags, - pcb->flags & TF_TIMESTAMP ? TF_SEG_OPTS_TS : 0); -#else - return tcp_enqueue(pcb, (void *)data, len, 0, apiflags, 0); -#endif - } - return ERR_OK; - } else { - LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_STATE | LWIP_DBG_LEVEL_SEVERE, ("tcp_write() called in invalid state\n")); - return ERR_CONN; + struct tcp_seg *seg; + u8_t optlen = LWIP_TCP_OPT_LENGTH(optflags); + + if ((seg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG)) == NULL) { + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_create_segment: no memory.\n")); + pbuf_free(p); + return NULL; } -} + seg->flags = optflags; + seg->next = NULL; + seg->p = p; + seg->len = p->tot_len - optlen; +#if TCP_OVERSIZE_DBGCHECK + seg->oversize_left = 0; +#endif /* TCP_OVERSIZE_DBGCHECK */ +#if TCP_CHECKSUM_ON_COPY + seg->chksum = 0; + seg->chksum_swapped = 0; + /* check optflags */ + LWIP_ASSERT("invalid optflags passed: TF_SEG_DATA_CHECKSUMMED", + (optflags & TF_SEG_DATA_CHECKSUMMED) == 0); +#endif /* TCP_CHECKSUM_ON_COPY */ + + /* build TCP header */ + if (pbuf_header(p, TCP_HLEN)) { + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_create_segment: no room for TCP header in pbuf.\n")); + TCP_STATS_INC(tcp.err); + tcp_seg_free(seg); + return NULL; + } + seg->tcphdr = (struct tcp_hdr *)seg->p->payload; + seg->tcphdr->src = htons(pcb->local_port); + seg->tcphdr->dest = htons(pcb->remote_port); + seg->tcphdr->seqno = htonl(seqno); + /* ackno is set in tcp_output */ + TCPH_HDRLEN_FLAGS_SET(seg->tcphdr, (5 + optlen / 4), flags); + /* wnd and chksum are set in tcp_output */ + seg->tcphdr->urgp = 0; + return seg; +} /** - * Enqueue data and/or TCP options for transmission + * Allocate a PBUF_RAM pbuf, perhaps with extra space at the end. * - * Called by tcp_connect(), tcp_listen_input(), tcp_send_ctrl() and tcp_write(). + * This function is like pbuf_alloc(layer, length, PBUF_RAM) except + * there may be extra bytes available at the end. * - * @param pcb Protocol control block for the TCP connection to enqueue data for. - * @param arg Pointer to the data to be enqueued for sending. - * @param len Data length in bytes - * @param flags tcp header flags to set in the outgoing segment - * @param apiflags combination of following flags : - * - TCP_WRITE_FLAG_COPY (0x01) data will be copied into memory belonging to the stack - * - TCP_WRITE_FLAG_MORE (0x02) for TCP connection, PSH flag will be set on last segment sent, - * @param optflags options to include in segment later on (see definition of struct tcp_seg) + * @param layer flag to define header size. + * @param length size of the pbuf's payload. + * @param max_length maximum usable size of payload+oversize. + * @param oversize pointer to a u16_t that will receive the number of usable tail bytes. + * @param pcb The TCP connection that willo enqueue the pbuf. + * @param apiflags API flags given to tcp_write. + * @param first_seg true when this pbuf will be used in the first enqueued segment. + * @param */ -err_t -tcp_enqueue(struct tcp_pcb *pcb, void *arg, u16_t len, - u8_t flags, u8_t apiflags, u8_t optflags) +#if TCP_OVERSIZE +static struct pbuf * +tcp_pbuf_prealloc(pbuf_layer layer, u16_t length, u16_t max_length, + u16_t *oversize, struct tcp_pcb *pcb, u8_t apiflags, + u8_t first_seg) { struct pbuf *p; - struct tcp_seg *seg, *useg, *queue; - u32_t seqno; - u16_t left, seglen; - void *ptr; - u16_t queuelen; - u8_t optlen; + u16_t alloc = length; + +#if LWIP_NETIF_TX_SINGLE_PBUF + LWIP_UNUSED_ARG(max_length); + LWIP_UNUSED_ARG(pcb); + LWIP_UNUSED_ARG(apiflags); + LWIP_UNUSED_ARG(first_seg); + /* always create MSS-sized pbufs */ + alloc = TCP_MSS; +#else /* LWIP_NETIF_TX_SINGLE_PBUF */ + if (length < max_length) { + /* Should we allocate an oversized pbuf, or just the minimum + * length required? If tcp_write is going to be called again + * before this segment is transmitted, we want the oversized + * buffer. If the segment will be transmitted immediately, we can + * save memory by allocating only length. We use a simple + * heuristic based on the following information: + * + * Did the user set TCP_WRITE_FLAG_MORE? + * + * Will the Nagle algorithm defer transmission of this segment? + */ + if ((apiflags & TCP_WRITE_FLAG_MORE) || + (!(pcb->flags & TF_NODELAY) && + (!first_seg || + pcb->unsent != NULL || + pcb->unacked != NULL))) { + alloc = LWIP_MIN(max_length, LWIP_MEM_ALIGN_SIZE(length + TCP_OVERSIZE)); + } + } +#endif /* LWIP_NETIF_TX_SINGLE_PBUF */ + p = pbuf_alloc(layer, alloc, PBUF_RAM); + if (p == NULL) { + return NULL; + } + LWIP_ASSERT("need unchained pbuf", p->next == NULL); + *oversize = p->len - length; + /* trim p->len to the currently used size */ + p->len = p->tot_len = length; + return p; +} +#else /* TCP_OVERSIZE */ +#define tcp_pbuf_prealloc(layer, length, mx, os, pcb, api, fst) pbuf_alloc((layer), (length), PBUF_RAM) +#endif /* TCP_OVERSIZE */ - LWIP_DEBUGF(TCP_OUTPUT_DEBUG, - ("tcp_enqueue(pcb=%p, arg=%p, len=%"U16_F", flags=%"X16_F", apiflags=%"U16_F")\n", - (void *)pcb, arg, len, (u16_t)flags, (u16_t)apiflags)); - LWIP_ERROR("tcp_enqueue: packet needs payload, options, or SYN/FIN (programmer violates API)", - ((len != 0) || (optflags != 0) || ((flags & (TCP_SYN | TCP_FIN)) != 0)), - return ERR_ARG;); - LWIP_ERROR("tcp_enqueue: len != 0 || arg == NULL (programmer violates API)", - ((len != 0) || (arg == NULL)), return ERR_ARG;); +#if TCP_CHECKSUM_ON_COPY +/** Add a checksum of newly added data to the segment */ +static void +tcp_seg_add_chksum(u16_t chksum, u16_t len, u16_t *seg_chksum, + u8_t *seg_chksum_swapped) +{ + u32_t helper; + /* add chksum to old chksum and fold to u16_t */ + helper = chksum + *seg_chksum; + chksum = FOLD_U32T(helper); + if ((len & 1) != 0) { + *seg_chksum_swapped = 1 - *seg_chksum_swapped; + chksum = SWAP_BYTES_IN_WORD(chksum); + } + *seg_chksum = chksum; +} +#endif /* TCP_CHECKSUM_ON_COPY */ + +/** Checks if tcp_write is allowed or not (checks state, snd_buf and snd_queuelen). + * + * @param pcb the tcp pcb to check for + * @param len length of data to send (checked agains snd_buf) + * @return ERR_OK if tcp_write is allowed to proceed, another err_t otherwise + */ +static err_t +tcp_write_checks(struct tcp_pcb *pcb, u16_t len) +{ + /* connection is in invalid state for data transmission? */ + if ((pcb->state != ESTABLISHED) && + (pcb->state != CLOSE_WAIT) && + (pcb->state != SYN_SENT) && + (pcb->state != SYN_RCVD)) { + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_STATE | LWIP_DBG_LEVEL_SEVERE, ("tcp_write() called in invalid state\n")); + return ERR_CONN; + } else if (len == 0) { + return ERR_OK; + } /* fail on too much data */ if (len > pcb->snd_buf) { - LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_LEVEL_WARNING, - ("tcp_enqueue: too much data (len=%"U16_F" > snd_buf=%"U16_F")\n", len, pcb->snd_buf)); + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too much data (len=%"U16_F" > snd_buf=%"U16_F")\n", + len, pcb->snd_buf)); pcb->flags |= TF_NAGLEMEMERR; return ERR_MEM; } - left = len; - ptr = arg; - optlen = LWIP_TCP_OPT_LENGTH(optflags); - - /* seqno will be the sequence number of the first segment enqueued - * by the call to this function. */ - seqno = pcb->snd_lbb; - - LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen)); + LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen)); /* If total number of pbufs on the unsent/unacked queues exceeds the * configured maximum, return an error */ - queuelen = pcb->snd_queuelen; /* check for configured max queuelen and possible overflow */ - if ((queuelen >= TCP_SND_QUEUELEN) || (queuelen > TCP_SNDQUEUELEN_OVERFLOW)) { - LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_LEVEL_WARNING, - ("tcp_enqueue: too long queue %"U16_F" (max %"U16_F")\n", queuelen, TCP_SND_QUEUELEN)); + if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) || (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) { + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too long queue %"U16_F" (max %"U16_F")\n", + pcb->snd_queuelen, TCP_SND_QUEUELEN)); TCP_STATS_INC(tcp.memerr); pcb->flags |= TF_NAGLEMEMERR; return ERR_MEM; } - if (queuelen != 0) { - LWIP_ASSERT("tcp_enqueue: pbufs on queue => at least one queue non-empty", + if (pcb->snd_queuelen != 0) { + LWIP_ASSERT("tcp_write: pbufs on queue => at least one queue non-empty", pcb->unacked != NULL || pcb->unsent != NULL); } else { - LWIP_ASSERT("tcp_enqueue: no pbufs on queue => both queues empty", + LWIP_ASSERT("tcp_write: no pbufs on queue => both queues empty", pcb->unacked == NULL && pcb->unsent == NULL); } + return ERR_OK; +} - /* First, break up the data into segments and tuck them together in - * the local "queue" variable. */ - useg = queue = seg = NULL; - seglen = 0; - while (queue == NULL || left > 0) { - /* The segment length (including options) should be at most the MSS */ - seglen = left > (pcb->mss - optlen) ? (pcb->mss - optlen) : left; - - /* Allocate memory for tcp_seg, and fill in fields. */ - seg = memp_malloc(MEMP_TCP_SEG); - if (seg == NULL) { - LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_LEVEL_SERIOUS, - ("tcp_enqueue: could not allocate memory for tcp_seg\n")); - goto memerr; - } - seg->next = NULL; - seg->p = NULL; +/** + * Write data for sending (but does not send it immediately). + * + * It waits in the expectation of more data being sent soon (as + * it can send them more efficiently by combining them together). + * To prompt the system to send data now, call tcp_output() after + * calling tcp_write(). + * + * @param pcb Protocol control block for the TCP connection to enqueue data for. + * @param arg Pointer to the data to be enqueued for sending. + * @param len Data length in bytes + * @param apiflags combination of following flags : + * - TCP_WRITE_FLAG_COPY (0x01) data will be copied into memory belonging to the stack + * - TCP_WRITE_FLAG_MORE (0x02) for TCP connection, PSH flag will be set on last segment sent, + * @return ERR_OK if enqueued, another err_t on error + */ +err_t +tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags) +{ + struct pbuf *concat_p = NULL; + struct tcp_seg *last_unsent = NULL, *seg = NULL, *prev_seg = NULL, *queue = NULL; + u16_t pos = 0; /* position in 'arg' data */ + u16_t queuelen; + u8_t optlen = 0; + u8_t optflags = 0; +#if TCP_OVERSIZE + u16_t oversize = 0; + u16_t oversize_used = 0; +#endif /* TCP_OVERSIZE */ +#if TCP_CHECKSUM_ON_COPY + u16_t concat_chksum = 0; + u8_t concat_chksum_swapped = 0; + u16_t concat_chksummed = 0; +#endif /* TCP_CHECKSUM_ON_COPY */ + err_t err; + +#if LWIP_NETIF_TX_SINGLE_PBUF + /* Always copy to try to create single pbufs for TX */ + apiflags |= TCP_WRITE_FLAG_COPY; +#endif /* LWIP_NETIF_TX_SINGLE_PBUF */ + + LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_write(pcb=%p, data=%p, len=%"U16_F", apiflags=%"U16_F")\n", + (void *)pcb, arg, len, (u16_t)apiflags)); + LWIP_ERROR("tcp_write: arg == NULL (programmer violates API)", + arg != NULL, return ERR_ARG;); + + err = tcp_write_checks(pcb, len); + if (err != ERR_OK) { + return err; + } + queuelen = pcb->snd_queuelen; - /* first segment of to-be-queued data? */ - if (queue == NULL) { - queue = seg; +#if LWIP_TCP_TIMESTAMPS + if ((pcb->flags & TF_TIMESTAMP)) { + optflags = TF_SEG_OPTS_TS; + optlen = LWIP_TCP_OPT_LENGTH(TF_SEG_OPTS_TS); + } +#endif /* LWIP_TCP_TIMESTAMPS */ + + + /* + * TCP segmentation is done in three phases with increasing complexity: + * + * 1. Copy data directly into an oversized pbuf. + * 2. Chain a new pbuf to the end of pcb->unsent. + * 3. Create new segments. + * + * We may run out of memory at any point. In that case we must + * return ERR_MEM and not change anything in pcb. Therefore, all + * changes are recorded in local variables and committed at the end + * of the function. Some pcb fields are maintained in local copies: + * + * queuelen = pcb->snd_queuelen + * oversize = pcb->unsent_oversize + * + * These variables are set consistently by the phases: + * + * seg points to the last segment tampered with. + * + * pos records progress as data is segmented. + */ + + /* Find the tail of the unsent queue. */ + if (pcb->unsent != NULL) { + u16_t space; + u16_t unsent_optlen; + + /* @todo: this could be sped up by keeping last_unsent in the pcb */ + for (last_unsent = pcb->unsent; last_unsent->next != NULL; + last_unsent = last_unsent->next); + + /* Usable space at the end of the last unsent segment */ + unsent_optlen = LWIP_TCP_OPT_LENGTH(last_unsent->flags); + space = pcb->mss - (last_unsent->len + unsent_optlen); + + /* + * Phase 1: Copy data directly into an oversized pbuf. + * + * The number of bytes copied is recorded in the oversize_used + * variable. The actual copying is done at the bottom of the + * function. + */ +#if TCP_OVERSIZE +#if TCP_OVERSIZE_DBGCHECK + /* check that pcb->unsent_oversize matches last_unsent->unsent_oversize */ + LWIP_ASSERT("unsent_oversize mismatch (pcb vs. last_unsent)", + pcb->unsent_oversize == last_unsent->oversize_left); +#endif /* TCP_OVERSIZE_DBGCHECK */ + oversize = pcb->unsent_oversize; + if (oversize > 0) { + LWIP_ASSERT("inconsistent oversize vs. space", oversize_used <= space); + seg = last_unsent; + oversize_used = oversize < len ? oversize : len; + pos += oversize_used; + oversize -= oversize_used; + space -= oversize_used; } - /* subsequent segments of to-be-queued data */ - else { - /* Attach the segment to the end of the queued segments */ - LWIP_ASSERT("useg != NULL", useg != NULL); - useg->next = seg; + /* now we are either finished or oversize is zero */ + LWIP_ASSERT("inconsistend oversize vs. len", (oversize == 0) || (pos == len)); +#endif /* TCP_OVERSIZE */ + + /* + * Phase 2: Chain a new pbuf to the end of pcb->unsent. + * + * We don't extend segments containing SYN/FIN flags or options + * (len==0). The new pbuf is kept in concat_p and pbuf_cat'ed at + * the end. + */ + if ((pos < len) && (space > 0) && (last_unsent->len > 0)) { + u16_t seglen = space < len - pos ? space : len - pos; + seg = last_unsent; + + /* Create a pbuf with a copy or reference to seglen bytes. We + * can use PBUF_RAW here since the data appears in the middle of + * a segment. A header will never be prepended. */ + if (apiflags & TCP_WRITE_FLAG_COPY) { + /* Data is copied */ + if ((concat_p = tcp_pbuf_prealloc(PBUF_RAW, seglen, space, &oversize, pcb, apiflags, 1)) == NULL) { + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, + ("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n", + seglen)); + goto memerr; + } +#if TCP_OVERSIZE_DBGCHECK + last_unsent->oversize_left = oversize; +#endif /* TCP_OVERSIZE_DBGCHECK */ + TCP_DATA_COPY2(concat_p->payload, (u8_t*)arg + pos, seglen, &concat_chksum, &concat_chksum_swapped); +#if TCP_CHECKSUM_ON_COPY + concat_chksummed += seglen; +#endif /* TCP_CHECKSUM_ON_COPY */ + } else { + /* Data is not copied */ + if ((concat_p = pbuf_alloc(PBUF_RAW, seglen, PBUF_ROM)) == NULL) { + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, + ("tcp_write: could not allocate memory for zero-copy pbuf\n")); + goto memerr; + } +#if TCP_CHECKSUM_ON_COPY + /* calculate the checksum of nocopy-data */ + tcp_seg_add_chksum(~inet_chksum((u8_t*)arg + pos, seglen), seglen, + &concat_chksum, &concat_chksum_swapped); + concat_chksummed += seglen; +#endif /* TCP_CHECKSUM_ON_COPY */ + /* reference the non-volatile payload data */ + concat_p->payload = (u8_t*)arg + pos; + } + + pos += seglen; + queuelen += pbuf_clen(concat_p); } - /* remember last segment of to-be-queued data for next iteration */ - useg = seg; + } else { +#if TCP_OVERSIZE + LWIP_ASSERT("unsent_oversize mismatch (pcb->unsent is NULL)", + pcb->unsent_oversize == 0); +#endif /* TCP_OVERSIZE */ + } + + /* + * Phase 3: Create new segments. + * + * The new segments are chained together in the local 'queue' + * variable, ready to be appended to pcb->unsent. + */ + while (pos < len) { + struct pbuf *p; + u16_t left = len - pos; + u16_t max_len = pcb->mss - optlen; + u16_t seglen = left > max_len ? max_len : left; +#if TCP_CHECKSUM_ON_COPY + u16_t chksum = 0; + u8_t chksum_swapped = 0; +#endif /* TCP_CHECKSUM_ON_COPY */ - /* If copy is set, memory should be allocated - * and data copied into pbuf, otherwise data comes from - * ROM or other static memory, and need not be copied. */ if (apiflags & TCP_WRITE_FLAG_COPY) { - if ((seg->p = pbuf_alloc(PBUF_TRANSPORT, seglen + optlen, PBUF_RAM)) == NULL) { - LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_LEVEL_SERIOUS, - ("tcp_enqueue : could not allocate memory for pbuf copy size %"U16_F"\n", seglen)); + /* If copy is set, memory should be allocated and data copied + * into pbuf */ + if ((p = tcp_pbuf_prealloc(PBUF_TRANSPORT, seglen + optlen, pcb->mss, &oversize, pcb, apiflags, queue == NULL)) == NULL) { + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n", seglen)); goto memerr; } - LWIP_ASSERT("check that first pbuf can hold the complete seglen", - (seg->p->len >= seglen + optlen)); - queuelen += pbuf_clen(seg->p); - if (arg != NULL) { - MEMCPY((char *)seg->p->payload + optlen, ptr, seglen); - } - seg->dataptr = seg->p->payload; - } - /* do not copy data */ - else { - /* First, allocate a pbuf for the headers. */ - if ((seg->p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) { - LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_LEVEL_SERIOUS, - ("tcp_enqueue: could not allocate memory for header pbuf\n")); + LWIP_ASSERT("tcp_write: check that first pbuf can hold the complete seglen", + (p->len >= seglen)); + TCP_DATA_COPY2((char *)p->payload + optlen, (u8_t*)arg + pos, seglen, &chksum, &chksum_swapped); + } else { + /* Copy is not set: First allocate a pbuf for holding the data. + * Since the referenced data is available at least until it is + * sent out on the link (as it has to be ACKed by the remote + * party) we can safely use PBUF_ROM instead of PBUF_REF here. + */ + struct pbuf *p2; +#if TCP_OVERSIZE + LWIP_ASSERT("oversize == 0", oversize == 0); +#endif /* TCP_OVERSIZE */ + if ((p2 = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_ROM)) == NULL) { + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: could not allocate memory for zero-copy pbuf\n")); goto memerr; } - queuelen += pbuf_clen(seg->p); - - /* Second, allocate a pbuf for holding the data. - * since the referenced data is available at least until it is sent out on the - * link (as it has to be ACKed by the remote party) we can safely use PBUF_ROM - * instead of PBUF_REF here. - */ - if (left > 0) { - if ((p = pbuf_alloc(PBUF_RAW, seglen, PBUF_ROM)) == NULL) { - /* If allocation fails, we have to deallocate the header pbuf as well. */ - pbuf_free(seg->p); - seg->p = NULL; - LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_LEVEL_SERIOUS, - ("tcp_enqueue: could not allocate memory for zero-copy pbuf\n")); - goto memerr; - } - ++queuelen; - /* reference the non-volatile payload data */ - p->payload = ptr; - seg->dataptr = ptr; - - /* Concatenate the headers and data pbufs together. */ - pbuf_cat(seg->p/*header*/, p/*data*/); - p = NULL; +#if TCP_CHECKSUM_ON_COPY + /* calculate the checksum of nocopy-data */ + chksum = ~inet_chksum((u8_t*)arg + pos, seglen); +#endif /* TCP_CHECKSUM_ON_COPY */ + /* reference the non-volatile payload data */ + p2->payload = (u8_t*)arg + pos; + + /* Second, allocate a pbuf for the headers. */ + if ((p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) { + /* If allocation fails, we have to deallocate the data pbuf as + * well. */ + pbuf_free(p2); + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: could not allocate memory for header pbuf\n")); + goto memerr; } + /* Concatenate the headers and data pbufs together. */ + pbuf_cat(p/*header*/, p2/*data*/); } + queuelen += pbuf_clen(p); + /* Now that there are more segments queued, we check again if the - length of the queue exceeds the configured maximum or overflows. */ + * length of the queue exceeds the configured maximum or + * overflows. */ if ((queuelen > TCP_SND_QUEUELEN) || (queuelen > TCP_SNDQUEUELEN_OVERFLOW)) { - LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_LEVEL_SERIOUS, - ("tcp_enqueue: queue too long %"U16_F" (%"U16_F")\n", queuelen, TCP_SND_QUEUELEN)); + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: queue too long %"U16_F" (%"U16_F")\n", queuelen, TCP_SND_QUEUELEN)); + pbuf_free(p); goto memerr; } - seg->len = seglen; - - /* build TCP header */ - if (pbuf_header(seg->p, TCP_HLEN)) { - LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("tcp_enqueue: no room for TCP header in pbuf.\n")); - TCP_STATS_INC(tcp.err); + if ((seg = tcp_create_segment(pcb, p, 0, pcb->snd_lbb + pos, optflags)) == NULL) { goto memerr; } - seg->tcphdr = seg->p->payload; - seg->tcphdr->src = htons(pcb->local_port); - seg->tcphdr->dest = htons(pcb->remote_port); - seg->tcphdr->seqno = htonl(seqno); - seg->tcphdr->urgp = 0; - TCPH_FLAGS_SET(seg->tcphdr, flags); - /* don't fill in tcphdr->ackno and tcphdr->wnd until later */ - - seg->flags = optflags; - - /* Set the length of the header */ - TCPH_HDRLEN_SET(seg->tcphdr, (5 + optlen / 4)); - LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_TRACE, ("tcp_enqueue: queueing %"U32_F":%"U32_F" (0x%"X16_F")\n", +#if TCP_OVERSIZE_DBGCHECK + seg->oversize_left = oversize; +#endif /* TCP_OVERSIZE_DBGCHECK */ +#if TCP_CHECKSUM_ON_COPY + seg->chksum = chksum; + seg->chksum_swapped = chksum_swapped; + seg->flags |= TF_SEG_DATA_CHECKSUMMED; +#endif /* TCP_CHECKSUM_ON_COPY */ + + /* first segment of to-be-queued data? */ + if (queue == NULL) { + queue = seg; + } else { + /* Attach the segment to the end of the queued segments */ + LWIP_ASSERT("prev_seg != NULL", prev_seg != NULL); + prev_seg->next = seg; + } + /* remember last segment of to-be-queued data for next iteration */ + prev_seg = seg; + + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_TRACE, ("tcp_write: queueing %"U32_F":%"U32_F"\n", ntohl(seg->tcphdr->seqno), - ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg), - (u16_t)flags)); + ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg))); - left -= seglen; - seqno += seglen; - ptr = (void *)((u8_t *)ptr + seglen); + pos += seglen; } - /* Now that the data to be enqueued has been broken up into TCP - segments in the queue variable, we add them to the end of the - pcb->unsent queue. */ - if (pcb->unsent == NULL) { - useg = NULL; - } - else { - for (useg = pcb->unsent; useg->next != NULL; useg = useg->next); - } - /* { useg is last segment on the unsent queue, NULL if list is empty } */ - - /* If there is room in the last pbuf on the unsent queue, - chain the first pbuf on the queue together with that. */ - if (useg != NULL && - TCP_TCPLEN(useg) != 0 && - !(TCPH_FLAGS(useg->tcphdr) & (TCP_SYN | TCP_FIN)) && - (!(flags & (TCP_SYN | TCP_FIN)) || (flags == TCP_FIN)) && - /* fit within max seg size */ - (useg->len + queue->len <= pcb->mss) && - /* only concatenate segments with the same options */ - (useg->flags == queue->flags) && - /* segments are consecutive */ - (ntohl(useg->tcphdr->seqno) + useg->len == ntohl(queue->tcphdr->seqno)) ) { - /* Remove TCP header from first segment of our to-be-queued list */ - if(pbuf_header(queue->p, -(TCP_HLEN + optlen))) { - /* Can we cope with this failing? Just assert for now */ - LWIP_ASSERT("pbuf_header failed\n", 0); - TCP_STATS_INC(tcp.err); - goto memerr; - } - if (queue->p->len == 0) { - /* free the first (header-only) pbuf if it is now empty (contained only headers) */ - struct pbuf *old_q = queue->p; - queue->p = queue->p->next; - old_q->next = NULL; - queuelen--; - pbuf_free(old_q); - } - if (flags & TCP_FIN) { - /* the new segment contains only FIN, no data -> put the FIN into the last segment */ - LWIP_ASSERT("FIN enqueued together with data", queue->p == NULL && queue->len == 0); - TCPH_SET_FLAG(useg->tcphdr, TCP_FIN); - } else { - LWIP_ASSERT("zero-length pbuf", (queue->p != NULL) && (queue->p->len > 0)); - pbuf_cat(useg->p, queue->p); - useg->len += queue->len; - useg->next = queue->next; - } + /* + * All three segmentation phases were successful. We can commit the + * transaction. + */ - LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("tcp_enqueue: chaining segments, new len %"U16_F"\n", useg->len)); - if (seg == queue) { - seg = useg; - seglen = useg->len; + /* + * Phase 1: If data has been added to the preallocated tail of + * last_unsent, we update the length fields of the pbuf chain. + */ +#if TCP_OVERSIZE + if (oversize_used > 0) { + struct pbuf *p; + /* Bump tot_len of whole chain, len of tail */ + for (p = last_unsent->p; p; p = p->next) { + p->tot_len += oversize_used; + if (p->next == NULL) { + TCP_DATA_COPY((char *)p->payload + p->len, arg, oversize_used, last_unsent); + p->len += oversize_used; + } } - memp_free(MEMP_TCP_SEG, queue); + last_unsent->len += oversize_used; +#if TCP_OVERSIZE_DBGCHECK + last_unsent->oversize_left -= oversize_used; +#endif /* TCP_OVERSIZE_DBGCHECK */ } - else { - /* empty list */ - if (useg == NULL) { - /* initialize list with this segment */ - pcb->unsent = queue; - } - /* enqueue segment */ - else { - useg->next = queue; + pcb->unsent_oversize = oversize; +#endif /* TCP_OVERSIZE */ + + /* + * Phase 2: concat_p can be concatenated onto last_unsent->p + */ + if (concat_p != NULL) { + LWIP_ASSERT("tcp_write: cannot concatenate when pcb->unsent is empty", + (last_unsent != NULL)); + pbuf_cat(last_unsent->p, concat_p); + last_unsent->len += concat_p->tot_len; +#if TCP_CHECKSUM_ON_COPY + if (concat_chksummed) { + tcp_seg_add_chksum(concat_chksum, concat_chksummed, &last_unsent->chksum, + &last_unsent->chksum_swapped); + last_unsent->flags |= TF_SEG_DATA_CHECKSUMMED; } +#endif /* TCP_CHECKSUM_ON_COPY */ } - if ((flags & TCP_SYN) || (flags & TCP_FIN)) { - ++len; - } - if (flags & TCP_FIN) { - pcb->flags |= TF_FIN; + + /* + * Phase 3: Append queue to pcb->unsent. Queue may be NULL, but that + * is harmless + */ + if (last_unsent == NULL) { + pcb->unsent = queue; + } else { + last_unsent->next = queue; } - pcb->snd_lbb += len; + /* + * Finally update the pcb state. + */ + pcb->snd_lbb += len; pcb->snd_buf -= len; - - /* update number of segments on the queues */ pcb->snd_queuelen = queuelen; - LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue: %"S16_F" (after enqueued)\n", pcb->snd_queuelen)); + + LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: %"S16_F" (after enqueued)\n", + pcb->snd_queuelen)); if (pcb->snd_queuelen != 0) { - LWIP_ASSERT("tcp_enqueue: valid queue length", - pcb->unacked != NULL || pcb->unsent != NULL); + LWIP_ASSERT("tcp_write: valid queue length", + pcb->unacked != NULL || pcb->unsent != NULL); } - /* Set the PSH flag in the last segment that we enqueued, but only - if the segment has data (indicated by seglen > 0). */ - if (seg != NULL && seglen > 0 && seg->tcphdr != NULL && ((apiflags & TCP_WRITE_FLAG_MORE)==0)) { + /* Set the PSH flag in the last segment that we enqueued. */ + if (seg != NULL && seg->tcphdr != NULL && ((apiflags & TCP_WRITE_FLAG_MORE)==0)) { TCPH_SET_FLAG(seg->tcphdr, TCP_PSH); } @@ -426,17 +687,130 @@ memerr: pcb->flags |= TF_NAGLEMEMERR; TCP_STATS_INC(tcp.memerr); + if (concat_p != NULL) { + pbuf_free(concat_p); + } if (queue != NULL) { tcp_segs_free(queue); } if (pcb->snd_queuelen != 0) { - LWIP_ASSERT("tcp_enqueue: valid queue length", pcb->unacked != NULL || + LWIP_ASSERT("tcp_write: valid queue length", pcb->unacked != NULL || pcb->unsent != NULL); } - LWIP_DEBUGF(TCP_QLEN_DEBUG | LWIP_DBG_STATE, ("tcp_enqueue: %"S16_F" (with mem err)\n", pcb->snd_queuelen)); + LWIP_DEBUGF(TCP_QLEN_DEBUG | LWIP_DBG_STATE, ("tcp_write: %"S16_F" (with mem err)\n", pcb->snd_queuelen)); return ERR_MEM; } +/** + * Enqueue TCP options for transmission. + * + * Called by tcp_connect(), tcp_listen_input(), and tcp_send_ctrl(). + * + * @param pcb Protocol control block for the TCP connection. + * @param flags TCP header flags to set in the outgoing segment. + * @param optdata pointer to TCP options, or NULL. + * @param optlen length of TCP options in bytes. + */ +err_t +tcp_enqueue_flags(struct tcp_pcb *pcb, u8_t flags) +{ + struct pbuf *p; + struct tcp_seg *seg; + u8_t optflags = 0; + u8_t optlen = 0; + + LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue_flags: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen)); + + LWIP_ASSERT("tcp_enqueue_flags: need either TCP_SYN or TCP_FIN in flags (programmer violates API)", + (flags & (TCP_SYN | TCP_FIN)) != 0); + + /* check for configured max queuelen and possible overflow */ + if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) || (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) { + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_enqueue_flags: too long queue %"U16_F" (max %"U16_F")\n", + pcb->snd_queuelen, TCP_SND_QUEUELEN)); + TCP_STATS_INC(tcp.memerr); + pcb->flags |= TF_NAGLEMEMERR; + return ERR_MEM; + } + + if (flags & TCP_SYN) { + optflags = TF_SEG_OPTS_MSS; + } +#if LWIP_TCP_TIMESTAMPS + if ((pcb->flags & TF_TIMESTAMP)) { + optflags |= TF_SEG_OPTS_TS; + } +#endif /* LWIP_TCP_TIMESTAMPS */ + optlen = LWIP_TCP_OPT_LENGTH(optflags); + + /* tcp_enqueue_flags is always called with either SYN or FIN in flags. + * We need one available snd_buf byte to do that. + * This means we can't send FIN while snd_buf==0. A better fix would be to + * not include SYN and FIN sequence numbers in the snd_buf count. */ + if (pcb->snd_buf == 0) { + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_enqueue_flags: no send buffer available\n")); + TCP_STATS_INC(tcp.memerr); + return ERR_MEM; + } + + /* Allocate pbuf with room for TCP header + options */ + if ((p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) { + pcb->flags |= TF_NAGLEMEMERR; + TCP_STATS_INC(tcp.memerr); + return ERR_MEM; + } + LWIP_ASSERT("tcp_enqueue_flags: check that first pbuf can hold optlen", + (p->len >= optlen)); + + /* Allocate memory for tcp_seg, and fill in fields. */ + if ((seg = tcp_create_segment(pcb, p, flags, pcb->snd_lbb, optflags)) == NULL) { + pcb->flags |= TF_NAGLEMEMERR; + TCP_STATS_INC(tcp.memerr); + return ERR_MEM; + } + LWIP_ASSERT("seg->tcphdr not aligned", ((mem_ptr_t)seg->tcphdr % MEM_ALIGNMENT) == 0); + LWIP_ASSERT("tcp_enqueue_flags: invalid segment length", seg->len == 0); + + LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_TRACE, + ("tcp_enqueue_flags: queueing %"U32_F":%"U32_F" (0x%"X16_F")\n", + ntohl(seg->tcphdr->seqno), + ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg), + (u16_t)flags)); + + /* Now append seg to pcb->unsent queue */ + if (pcb->unsent == NULL) { + pcb->unsent = seg; + } else { + struct tcp_seg *useg; + for (useg = pcb->unsent; useg->next != NULL; useg = useg->next); + useg->next = seg; + } +#if TCP_OVERSIZE + /* The new unsent tail has no space */ + pcb->unsent_oversize = 0; +#endif /* TCP_OVERSIZE */ + + /* SYN and FIN bump the sequence number */ + if ((flags & TCP_SYN) || (flags & TCP_FIN)) { + pcb->snd_lbb++; + /* optlen does not influence snd_buf */ + pcb->snd_buf--; + } + if (flags & TCP_FIN) { + pcb->flags |= TF_FIN; + } + + /* update number of segments on the queues */ + pcb->snd_queuelen += pbuf_clen(seg->p); + LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue_flags: %"S16_F" (after enqueued)\n", pcb->snd_queuelen)); + if (pcb->snd_queuelen != 0) { + LWIP_ASSERT("tcp_enqueue_flags: invalid queue length", + pcb->unacked != NULL || pcb->unsent != NULL); + } + + return ERR_OK; +} + #if LWIP_TCP_TIMESTAMPS /* Build a timestamp option (12 bytes long) at the specified options pointer) @@ -448,7 +822,7 @@ static void tcp_build_timestamp_option(struct tcp_pcb *pcb, u32_t *opts) { /* Pad with two NOP options to make everything nicely aligned */ - opts[0] = htonl(0x0101080A); + opts[0] = PP_HTONL(0x0101080A); opts[1] = htonl(sys_now()); opts[2] = htonl(pcb->ts_recent); } @@ -470,18 +844,18 @@ tcp_send_empty_ack(struct tcp_pcb *pcb) optlen = LWIP_TCP_OPT_LENGTH(TF_SEG_OPTS_TS); } #endif - p = pbuf_alloc(PBUF_IP, TCP_HLEN + optlen, PBUF_RAM); + + p = tcp_output_alloc_header(pcb, optlen, 0, htonl(pcb->snd_nxt)); if (p == NULL) { LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: (ACK) could not allocate pbuf\n")); return ERR_BUF; } + tcphdr = (struct tcp_hdr *)p->payload; LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: sending ACK for %"U32_F"\n", pcb->rcv_nxt)); /* remove ACK flags from the PCB, as we send an empty ACK now */ pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW); - tcphdr = tcp_output_set_header(pcb, p, optlen, htonl(pcb->snd_nxt)); - /* NB. MSS option is only sent on SYNs, so ignore it here */ #if LWIP_TCP_TIMESTAMPS pcb->ts_lastacksent = pcb->rcv_nxt; @@ -581,10 +955,10 @@ tcp_output(struct tcp_pcb *pcb) (TCPH_FLAGS(seg->tcphdr) & TCP_RST) == 0); /* Stop sending if the nagle algorithm would prevent it * Don't stop: - * - if tcp_enqueue had a memory error before (prevent delayed ACK timeout) or + * - if tcp_write had a memory error before (prevent delayed ACK timeout) or * - if FIN was already enqueued for this PCB (SYN is always alone in a segment - * either seg->next != NULL or pcb->unacked == NULL; - * RST is no sent using tcp_enqueue/tcp_output. + * RST is no sent using tcp_write/tcp_output. */ if((tcp_do_output_nagle(pcb) == 0) && ((pcb->flags & (TF_NAGLEMEMERR | TF_FIN)) == 0)){ @@ -623,7 +997,7 @@ tcp_output(struct tcp_pcb *pcb) /* In the case of fast retransmit, the packet should not go to the tail * of the unacked queue, but rather somewhere before it. We need to check for * this case. -STJ Jul 27, 2004 */ - if (TCP_SEQ_LT(ntohl(seg->tcphdr->seqno), ntohl(useg->tcphdr->seqno))){ + if (TCP_SEQ_LT(ntohl(seg->tcphdr->seqno), ntohl(useg->tcphdr->seqno))) { /* add segment to before tail of unacked list, keeping the list sorted */ struct tcp_seg **cur_seg = &(pcb->unacked); while (*cur_seg && @@ -644,6 +1018,12 @@ tcp_output(struct tcp_pcb *pcb) } seg = pcb->unsent; } +#if TCP_OVERSIZE + if (pcb->unsent == NULL) { + /* last unsent has been removed, reset unsent_oversize */ + pcb->unsent_oversize = 0; + } +#endif /* TCP_OVERSIZE */ if (seg != NULL && pcb->persist_backoff == 0 && ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len > pcb->snd_wnd) { @@ -683,7 +1063,8 @@ tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb) /* Add any requested options. NB MSS option is only set on SYN packets, so ignore it here */ - opts = (u32_t *)(seg->tcphdr + 1); + LWIP_ASSERT("seg->tcphdr not aligned", ((mem_ptr_t)seg->tcphdr % MEM_ALIGNMENT) == 0); + opts = (u32_t *)(void *)(seg->tcphdr + 1); if (seg->flags & TF_SEG_OPTS_MSS) { TCP_BUILD_MSS_OPTION(*opts); opts += 1; @@ -697,6 +1078,12 @@ tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb) } #endif + /* Set retransmission timer running if it is not currently enabled + This must be set before checking the route. */ + if (pcb->rtime == -1) { + pcb->rtime = 0; + } + /* If we don't have a local IP address, we get one by calling ip_route(). */ if (ip_addr_isany(&(pcb->local_ip))) { @@ -704,13 +1091,9 @@ tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb) if (netif == NULL) { return; } - ip_addr_set(&(pcb->local_ip), &(netif->ip_addr)); + ip_addr_copy(pcb->local_ip, netif->ip_addr); } - /* Set retransmission timer running if it is not currently enabled */ - if(pcb->rtime == -1) - pcb->rtime = 0; - if (pcb->rttest == 0) { pcb->rttest = tcp_ticks; pcb->rtseq = ntohl(seg->tcphdr->seqno); @@ -730,11 +1113,45 @@ tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb) seg->tcphdr->chksum = 0; #if CHECKSUM_GEN_TCP - seg->tcphdr->chksum = inet_chksum_pseudo(seg->p, - &(pcb->local_ip), +#if TCP_CHECKSUM_ON_COPY + { + u32_t acc; +#if TCP_CHECKSUM_ON_COPY_SANITY_CHECK + u16_t chksum_slow = inet_chksum_pseudo(seg->p, &(pcb->local_ip), + &(pcb->remote_ip), + IP_PROTO_TCP, seg->p->tot_len); +#endif /* TCP_CHECKSUM_ON_COPY_SANITY_CHECK */ + if ((seg->flags & TF_SEG_DATA_CHECKSUMMED) == 0) { + LWIP_ASSERT("data included but not checksummed", + seg->p->tot_len == (TCPH_HDRLEN(seg->tcphdr) * 4)); + } + + /* rebuild TCP header checksum (TCP header changes for retransmissions!) */ + acc = inet_chksum_pseudo_partial(seg->p, &(pcb->local_ip), &(pcb->remote_ip), - IP_PROTO_TCP, seg->p->tot_len); -#endif + IP_PROTO_TCP, seg->p->tot_len, TCPH_HDRLEN(seg->tcphdr) * 4); + /* add payload checksum */ + if (seg->chksum_swapped) { + seg->chksum = SWAP_BYTES_IN_WORD(seg->chksum); + seg->chksum_swapped = 0; + } + acc += (u16_t)~(seg->chksum); + seg->tcphdr->chksum = FOLD_U32T(acc); +#if TCP_CHECKSUM_ON_COPY_SANITY_CHECK + if (chksum_slow != seg->tcphdr->chksum) { + LWIP_DEBUGF(TCP_DEBUG | LWIP_DBG_LEVEL_WARNING, + ("tcp_output_segment: calculated checksum is %"X16_F" instead of %"X16_F"\n", + seg->tcphdr->chksum, chksum_slow)); + seg->tcphdr->chksum = chksum_slow; + } +#endif /* TCP_CHECKSUM_ON_COPY_SANITY_CHECK */ + } +#else /* TCP_CHECKSUM_ON_COPY */ + seg->tcphdr->chksum = inet_chksum_pseudo(seg->p, &(pcb->local_ip), + &(pcb->remote_ip), + IP_PROTO_TCP, seg->p->tot_len); +#endif /* TCP_CHECKSUM_ON_COPY */ +#endif /* CHECKSUM_GEN_TCP */ TCP_STATS_INC(tcp.xmit); #if LWIP_NETIF_HWADDRHINT @@ -768,7 +1185,7 @@ tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb) */ void tcp_rst(u32_t seqno, u32_t ackno, - struct ip_addr *local_ip, struct ip_addr *remote_ip, + ip_addr_t *local_ip, ip_addr_t *remote_ip, u16_t local_port, u16_t remote_port) { struct pbuf *p; @@ -781,17 +1198,16 @@ tcp_rst(u32_t seqno, u32_t ackno, LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr", (p->len >= sizeof(struct tcp_hdr))); - tcphdr = p->payload; + tcphdr = (struct tcp_hdr *)p->payload; tcphdr->src = htons(local_port); tcphdr->dest = htons(remote_port); tcphdr->seqno = htonl(seqno); tcphdr->ackno = htonl(ackno); - TCPH_FLAGS_SET(tcphdr, TCP_RST | TCP_ACK); - tcphdr->wnd = htons(TCP_WND); + TCPH_HDRLEN_FLAGS_SET(tcphdr, TCP_HLEN/4, TCP_RST | TCP_ACK); + tcphdr->wnd = PP_HTONS(TCP_WND); + tcphdr->chksum = 0; tcphdr->urgp = 0; - TCPH_HDRLEN_SET(tcphdr, 5); - tcphdr->chksum = 0; #if CHECKSUM_GEN_TCP tcphdr->chksum = inet_chksum_pseudo(p, local_ip, remote_ip, IP_PROTO_TCP, p->tot_len); @@ -900,10 +1316,11 @@ tcp_rexmit_fast(struct tcp_pcb *pcb) /* Set ssthresh to half of the minimum of the current * cwnd and the advertised window */ - if (pcb->cwnd > pcb->snd_wnd) + if (pcb->cwnd > pcb->snd_wnd) { pcb->ssthresh = pcb->snd_wnd / 2; - else + } else { pcb->ssthresh = pcb->cwnd / 2; + } /* The minimum value for ssthresh should be 2 MSS */ if (pcb->ssthresh < 2*pcb->mss) { @@ -935,23 +1352,19 @@ tcp_keepalive(struct tcp_pcb *pcb) struct tcp_hdr *tcphdr; LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: sending KEEPALIVE probe to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", - ip4_addr1(&pcb->remote_ip), ip4_addr2(&pcb->remote_ip), - ip4_addr3(&pcb->remote_ip), ip4_addr4(&pcb->remote_ip))); + ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip), + ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip))); LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: tcp_ticks %"U32_F" pcb->tmr %"U32_F" pcb->keep_cnt_sent %"U16_F"\n", tcp_ticks, pcb->tmr, pcb->keep_cnt_sent)); - p = pbuf_alloc(PBUF_IP, TCP_HLEN, PBUF_RAM); - + p = tcp_output_alloc_header(pcb, 0, 0, htonl(pcb->snd_nxt - 1)); if(p == NULL) { LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: could not allocate memory for pbuf\n")); return; } - LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr", - (p->len >= sizeof(struct tcp_hdr))); - - tcphdr = tcp_output_set_header(pcb, p, 0, htonl(pcb->snd_nxt - 1)); + tcphdr = (struct tcp_hdr *)p->payload; #if CHECKSUM_GEN_TCP tcphdr->chksum = inet_chksum_pseudo(p, &pcb->local_ip, &pcb->remote_ip, @@ -994,8 +1407,8 @@ tcp_zero_window_probe(struct tcp_pcb *pcb) LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: sending ZERO WINDOW probe to %" U16_F".%"U16_F".%"U16_F".%"U16_F"\n", - ip4_addr1(&pcb->remote_ip), ip4_addr2(&pcb->remote_ip), - ip4_addr3(&pcb->remote_ip), ip4_addr4(&pcb->remote_ip))); + ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip), + ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip))); LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: tcp_ticks %"U32_F @@ -1004,31 +1417,32 @@ tcp_zero_window_probe(struct tcp_pcb *pcb) seg = pcb->unacked; - if(seg == NULL) + if(seg == NULL) { seg = pcb->unsent; - - if(seg == NULL) + } + if(seg == NULL) { return; + } is_fin = ((TCPH_FLAGS(seg->tcphdr) & TCP_FIN) != 0) && (seg->len == 0); - len = is_fin ? TCP_HLEN : TCP_HLEN + 1; + /* we want to send one seqno: either FIN or data (no options) */ + len = is_fin ? 0 : 1; - p = pbuf_alloc(PBUF_IP, len, PBUF_RAM); + p = tcp_output_alloc_header(pcb, 0, len, seg->tcphdr->seqno); if(p == NULL) { LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: no memory for pbuf\n")); return; } - LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr", - (p->len >= sizeof(struct tcp_hdr))); - - tcphdr = tcp_output_set_header(pcb, p, 0, seg->tcphdr->seqno); + tcphdr = (struct tcp_hdr *)p->payload; if (is_fin) { /* FIN segment, no data */ TCPH_FLAGS_SET(tcphdr, TCP_ACK | TCP_FIN); } else { /* Data segment, copy in one byte from the head of the unacked queue */ - *((char *)p->payload + sizeof(struct tcp_hdr)) = *(char *)seg->dataptr; + struct tcp_hdr *thdr = (struct tcp_hdr *)seg->p->payload; + char *d = ((char *)p->payload + TCP_HLEN); + pbuf_copy_partial(seg->p, d, 1, TCPH_HDRLEN(thdr) * 4); } #if CHECKSUM_GEN_TCP |