This implementation is completely software based. Besides the CSUM, nothing is done in driver. The driver needs to allocate new skbs, copy and update the IP / TCP header.
Signed-off-by: Emmanuel Grumbach <[email protected]> --- drivers/net/wireless/iwlwifi/mvm/tx.c | 523 +++++++++++++++++++++++++++++++++- 1 file changed, 512 insertions(+), 11 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/mvm/tx.c b/drivers/net/wireless/iwlwifi/mvm/tx.c index 3243d73..27b8491 100644 --- a/drivers/net/wireless/iwlwifi/mvm/tx.c +++ b/drivers/net/wireless/iwlwifi/mvm/tx.c @@ -64,6 +64,9 @@ *****************************************************************************/ #include <linux/ieee80211.h> #include <linux/etherdevice.h> +#include <linux/if_vlan.h> +#include <net/tcp.h> +#include <net/ip.h> #include "iwl-trans.h" #include "iwl-eeprom-parse.h" @@ -422,14 +425,469 @@ int iwl_mvm_tx_skb_non_sta(struct iwl_mvm *mvm, struct sk_buff *skb) } /* - * Sets the fields in the Tx cmd that are crypto related + * Update the IP / TCP headers and recomputes the IP header CSUM + + * pseudo header CSUM. */ -int iwl_mvm_tx_skb(struct iwl_mvm *mvm, struct sk_buff *skb, - struct ieee80211_sta *sta) +static void iwl_update_ip_tcph(void *iph, struct tcphdr *tcph, bool ipv6, + unsigned int len, unsigned int tcp_seq_offset, + u16 num_segment) +{ + be32_add_cpu(&tcph->seq, tcp_seq_offset); + + if (ipv6) { + struct ipv6hdr *iphv6 = iph; + + iphv6->payload_len = cpu_to_be16(len + tcph->doff * 4); + + /* Compute CSUM on the the pseudo-header */ + tcph->check = ~csum_ipv6_magic(&iphv6->saddr, &iphv6->daddr, + len + tcph->doff * 4, + IPPROTO_TCP, 0); + } else { + struct iphdr *iphv4 = iph; + + iphv4->tot_len = + cpu_to_be16(len + tcph->doff * 4 + iphv4->ihl * 4); + be16_add_cpu(&iphv4->id, num_segment); + ip_send_check(iphv4); + + /* Compute CSUM on the the pseudo-header */ + tcph->check = ~csum_tcpudp_magic(iphv4->saddr, iphv4->daddr, + len + tcph->doff * 4, + IPPROTO_TCP, 0); + } +} + +/** + * struct iwl_lso_splitter - state of the split. + * @linear_payload_len: The lenth of the payload inside the header of the + * original GSO skb. + * @gso_frag_num: The fragment number from which to take the data in the + * original GSO skb. + * @gso_payload_len: The length of the payload in the original GSO skb. + * @gso_payload_pos: The incrementing position in the payload of the original + * GSO skb. + * @gso_offset_in_page: The offset in the page of &gso_frag_num. + * @gso_current_frag_size: The size of &gso_frag_num. + * @gso_offset_in_frag: The offset in the &gso_frag_num. + * @frag_in_mpdu: The index of the frag inside the new (split) MPDU. + * @mss: The maximal segment size. + * @si: Points to the the shared info of the original GSO skb. + * @ieee80211_hdr *hdr: Points to the WiFi header. + * @gso_nr_frags: The number of frags in the original GSO skb. + * @wifi_hdr_iv_len: The length of the WiFi header including IV. + * @tcp_fin: True if TCP_FIN is set in the original GSO skb. + * @tcp_push: True if TCP_PSH is set in the original GSO skb. + */ +struct iwl_lso_splitter { + unsigned int linear_payload_len; + unsigned int gso_frag_num; + unsigned int gso_payload_len; + unsigned int gso_payload_pos; + unsigned int gso_offset_in_page; + unsigned int gso_current_frag_size; + unsigned int gso_offset_in_frag; + unsigned int frag_in_mpdu; + unsigned int mss; + struct skb_shared_info *si; + struct ieee80211_hdr *hdr; + u8 gso_nr_frags; + u8 wifi_hdr_iv_len; + bool tcp_fin; + bool tcp_push; +}; + +/* + * Adds a TCP segment from skb_gso to skb. All the state is taken from + * and fed back to p. This function takes care about the payload only. + * This MSDU might already have msdu_sz bytes of payload that come from + * the original GSO skb's header. + */ +static unsigned int +iwl_add_tcp_segment(struct iwl_mvm *mvm, struct sk_buff *skb_gso, + struct sk_buff *skb, struct iwl_lso_splitter *p, + unsigned int msdu_sz) +{ + while (msdu_sz < p->mss) { + unsigned int frag_sz = + min_t(unsigned int, p->gso_current_frag_size, + p->mss - msdu_sz); + + if (p->frag_in_mpdu >= mvm->trans->max_skb_frags) { + IWL_ERR(mvm, "Max_skb_frags reached %d\n", + p->frag_in_mpdu); + return msdu_sz; + } + + skb_add_rx_frag(skb, p->frag_in_mpdu, + skb_frag_page(&p->si->frags[p->gso_frag_num]), + p->gso_offset_in_page, frag_sz, 0); + + /* We just added one frag to the mpdu ... */ + p->frag_in_mpdu++; + + /* ... which is frag_sz byte long ... */ + msdu_sz += frag_sz; + + /* ... we progress inside the gso frag ... */ + p->gso_offset_in_page += frag_sz; + + /* ... which is now getting smaller ... */ + p->gso_current_frag_size -= frag_sz; + + /* ... and we also progress in the global pos counting. */ + p->gso_payload_pos += frag_sz; + + /* + * This frag has some more bytes that can't fit into this MSDU, + * get a new one, and take a ref since this frag will be + * attached to two different skbs. + */ + if (p->gso_current_frag_size) { + skb_frag_ref(skb_gso, p->gso_frag_num); + break; + } + + /* We exhausted this frag go the next one ... */ + p->gso_frag_num++; + + /* ... if it exists ... */ + if (p->gso_frag_num == p->gso_nr_frags) + break; + + /* ... consider its full size ... */ + p->gso_current_frag_size = + skb_frag_size(&p->si->frags[p->gso_frag_num]); + /* ... and start from its beginning. */ + p->gso_offset_in_page = + p->si->frags[p->gso_frag_num].page_offset; + + /* If the MSDU is full, get a new one */ + if (frag_sz == p->mss) + break; + } + return msdu_sz; +} + +static __sum16 +iwl_sw_tcp_csum_offload(struct sk_buff *skb, + int tcph_offset, int len, int tcp_hdrlen) +{ + struct sk_buff *skb1; + __wsum csum; + + len += tcp_hdrlen; + skb1 = alloc_skb(len, GFP_ATOMIC); + BUG_ON(!skb1); + + skb_copy_bits(skb, tcph_offset, skb_put(skb1, len), len); + + skb_set_transport_header(skb1, 0); + skb1->csum_start = (unsigned char *)tcp_hdr(skb1) - skb1->head; + csum = skb_checksum(skb1, skb_checksum_start_offset(skb1), + skb1->len - skb_checksum_start_offset(skb1), + 0); + dev_kfree_skb(skb1); + + return csum_fold(csum); +} + +static u8 *get_page_pos(struct page **page, u8 *page_pos, size_t len) +{ + if (!*page) + goto alloc; + + if (page_pos + len < ((u8 *)page_address(*page)) + PAGE_SIZE) + return page_pos; + + __free_pages(*page, 0); + +alloc: + *page = alloc_pages(GFP_ATOMIC, 0); + if (!*page) + return NULL; + + return page_address(*page); +} + +static int iwl_add_msdu(struct iwl_mvm *mvm, struct sk_buff *skb_gso, + struct sk_buff *skb, struct page **hdr_page, + u8 **hdr_page_pos, int ip_id, + struct iwl_lso_splitter *p) +{ + + unsigned int tcp_seg_sz, snap_ip_tcp_len, copy_sz = 0; + bool ipv6 = p->si->gso_type & SKB_GSO_TCPV6; + u8 *start_hdr = *hdr_page_pos; + struct tcphdr *tcph; + struct iphdr *iph; + + snap_ip_tcp_len = + 8 + skb_network_header_len(skb_gso) + tcp_hdrlen(skb_gso); + copy_sz = min_t(unsigned int, p->linear_payload_len, p->mss); + + *hdr_page_pos = get_page_pos(hdr_page, *hdr_page_pos, snap_ip_tcp_len + copy_sz); + if (!*hdr_page_pos) + return -1; + + /* + * Copy SNAP / IP / TCP headers from the original GSO skb to the + * header page. + */ + skb_copy_bits(skb_gso, p->wifi_hdr_iv_len, + *hdr_page_pos, snap_ip_tcp_len); + + *hdr_page_pos += 8; + + iph = (void *)*hdr_page_pos; + *hdr_page_pos += skb_network_header_len(skb_gso); + + tcph = (void *)*hdr_page_pos; + *hdr_page_pos += tcp_hdrlen(skb_gso); + + /* + * If the original GSO skb had more than MSS bytes of payload in its + * header, consume it now. + */ + if (copy_sz) { + /* + * Since we copy from the tail pointer and don't update it, + * we can't have more than 1 mss in the linear_payload_len + * at this stage. Hence the limitation of 2 MSS in + * iwl_mvm_tx_tso. + */ + memcpy(*hdr_page_pos, skb_tail_pointer(skb_gso), copy_sz); + *hdr_page_pos += copy_sz; + p->gso_payload_pos += copy_sz; + p->linear_payload_len -= copy_sz; + } + + /* Add frag for SNAP / IP / TCP headers and possibly some payload .. */ + get_page(*hdr_page); + skb_add_rx_frag(skb, p->frag_in_mpdu, *hdr_page, + (u8 *)start_hdr - (u8 *)page_address(*hdr_page), + *hdr_page_pos - start_hdr, 0); + p->frag_in_mpdu++; + + /* .. and now add the payload coming from the frags. */ + tcp_seg_sz = iwl_add_tcp_segment(mvm, skb_gso, skb, p, copy_sz); + + iwl_update_ip_tcph(iph, tcph, ipv6, tcp_seg_sz, + p->gso_payload_pos - tcp_seg_sz, ip_id); + + /* Last segment, apply the TCP flags that may have been delayed */ + if (p->gso_payload_pos == p->gso_payload_len) { + if (p->tcp_push) + tcph->psh = 1; + if (p->tcp_fin) + tcph->fin = 1; + } + + if (IWL_MVM_SW_CSUM_OFFLOAD) + tcph->check = + iwl_sw_tcp_csum_offload(skb, skb->len - + tcp_seg_sz - + tcp_hdrlen(skb_gso), + tcp_seg_sz, tcp_hdrlen(skb_gso)); + skb->ip_summed = CHECKSUM_COMPLETE; + + return 0; +} + +static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff* skb_gso, + struct ieee80211_sta *sta, + struct sk_buff_head *mpdus_skb) +{ + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb_gso); + struct ieee80211_key_conf *keyconf = info->control.hw_key; + struct ieee80211_hdr *wifi_hdr = (void *)skb_gso->data; + bool ipv6 = skb_shinfo(skb_gso)->gso_type & SKB_GSO_TCPV6; + struct iwl_lso_splitter s = {}; + struct page *hdr_page; + unsigned int mpdu_sz; + u8 *hdr_page_pos; + int i; + + s.si = skb_shinfo(skb_gso); + s.mss = skb_shinfo(skb_gso)->gso_size; + s.gso_nr_frags = skb_shinfo(skb_gso)->nr_frags; + s.linear_payload_len = skb_tail_pointer(skb_gso) - + skb_transport_header(skb_gso) - tcp_hdrlen(skb_gso); + s.gso_payload_len = s.linear_payload_len + skb_gso->data_len; + + /* more than 2 * mss in the header? segment w/o GSO */ + if (s.linear_payload_len >= 2 * s.mss) { + struct sk_buff *tmp, *next; + char cb[sizeof(skb_gso->cb)]; + + memcpy(cb, skb_gso->cb, sizeof(cb)); + next = skb_gso_segment(skb_gso, 0); + if (IS_ERR(next)) + return -1; + else if (next) + consume_skb(skb_gso); + + while (next) { + tmp = next; + next = tmp->next; + memcpy(tmp->cb, cb, sizeof(tmp->cb)); + + tmp->prev = NULL; + tmp->next = NULL; + + __skb_queue_tail(mpdus_skb, tmp); + } + return 0; + } + + /* + * We got an GSO skb that may or may not have payload in its header. + * Re-use the same skb and chop the payload that can't fit into 1 MSS. + * First take the payload from the header... + */ + mpdu_sz = min_t(unsigned int, s.linear_payload_len, s.mss); + s.linear_payload_len -= mpdu_sz; + skb_gso->data_len = 0; + + /* + * ... and add now payload from the frags to get up to 1 MSS. + * If we have one mss already, mpdu_sz will be s.mss and + * this loop won't do much. + * Make sure we don't go beyond the limit of the origin GSO + * skb. + */ + s.gso_offset_in_frag = 0; + while (s.gso_frag_num < s.gso_nr_frags) { + unsigned int frag_sz = + skb_frag_size(&s.si->frags[s.gso_frag_num]); + + if ((s.mss - mpdu_sz) >= frag_sz) { + /* there is enough room for this entire frag */ + mpdu_sz += frag_sz; + skb_gso->data_len += frag_sz; + s.gso_frag_num++; + continue; + } + + /* + * Only part of this frag will fit and + * we now have a complete mss + */ + s.gso_offset_in_frag = s.mss - mpdu_sz; + skb_gso->data_len += (s.mss - mpdu_sz); + mpdu_sz = s.mss; + break; + } + + /* We have only one mss or even less? */ + if (WARN_ON(s.gso_frag_num == s.gso_nr_frags)) + goto err; + + /* remember the size of the remainder of the frag */ + s.gso_current_frag_size = skb_frag_size(&s.si->frags[s.gso_frag_num]) - + s.gso_offset_in_frag; + + /* shorten the skb_gso's frag to fit the mss */ + skb_frag_size_set(&s.si->frags[s.gso_frag_num], s.gso_offset_in_frag); + + /* translate to offset from the start of the page */ + s.gso_offset_in_page = + s.gso_offset_in_frag + s.si->frags[s.gso_frag_num].page_offset; + + /* remove all the other frags from skb_gso */ + skb_shinfo(skb_gso)->nr_frags = s.gso_frag_num + 1; + + /* take a temp ref to the last frag */ + skb_frag_ref(skb_gso, s.gso_frag_num); + + /* update the skb_gso's length fields */ + skb_gso->len -= (s.gso_payload_len - s.mss); + + /* + * If there is still some payload in the header, update the tail to the + * end of MSS. + */ + if (s.linear_payload_len) + skb_gso->tail -= s.linear_payload_len; + + /* + * Clear the bits in the TCP header that we delay for + * the last segment. + */ + s.tcp_push = tcp_hdr(skb_gso)->psh; + s.tcp_fin = tcp_hdr(skb_gso)->fin; + tcp_hdr(skb_gso)->psh = 0; + tcp_hdr(skb_gso)->fin = 0; + + /* update the IP / TCP header with the new length */ + iwl_update_ip_tcph(ip_hdr(skb_gso), tcp_hdr(skb_gso), + ipv6, s.mss, 0, 0); + + if (IWL_MVM_SW_CSUM_OFFLOAD) + tcp_hdr(skb_gso)->check = + iwl_sw_tcp_csum_offload(skb_gso, + (u8 *)tcp_hdr(skb_gso) - + (u8 *)skb_gso->data, + s.mss, tcp_hdrlen(skb_gso)); + + skb_gso->ip_summed = CHECKSUM_COMPLETE; + __skb_queue_tail(mpdus_skb, skb_gso); + + /* mss bytes have been consumed from the data */ + s.gso_payload_pos = s.mss; + i = 0; + + hdr_page = NULL; + hdr_page_pos = get_page_pos(&hdr_page, NULL, 1); + if (!hdr_page_pos) + return -1; + + s.hdr = wifi_hdr; + s.wifi_hdr_iv_len = ieee80211_hdrlen(wifi_hdr->frame_control); + if (keyconf && keyconf->cipher == WLAN_CIPHER_SUITE_CCMP) + s.wifi_hdr_iv_len += IEEE80211_CCMP_HDR_LEN; + + while (s.gso_payload_pos < s.gso_payload_len) { + struct sk_buff *skb = dev_alloc_skb(s.wifi_hdr_iv_len); + int ret; + s.frag_in_mpdu = 0; + + if (WARN_ON(s.gso_frag_num >= s.gso_nr_frags)) + break; + + if (!skb) + goto err; + + memcpy(skb->cb, skb_gso->cb, sizeof(skb->cb)); + + /* new MPDU - add WiFi header + IV */ + memcpy(skb_put(skb, s.wifi_hdr_iv_len), + wifi_hdr, s.wifi_hdr_iv_len); + + ret = iwl_add_msdu(mvm, skb_gso, skb, &hdr_page, + &hdr_page_pos, i++, &s); + if (ret < 0) { + skb_queue_purge(mpdus_skb); + goto err; + } + + __skb_queue_tail(mpdus_skb, skb); + } + + return 0; + +err: + if (hdr_page) + __free_pages(hdr_page, 0); + return -1; +} + +static int iwl_mvm_tx_mpdu(struct iwl_mvm *mvm, struct sk_buff *skb, + struct ieee80211_sta *sta) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; + struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta); struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); - struct iwl_mvm_sta *mvmsta; struct iwl_device_cmd *dev_cmd; struct iwl_tx_cmd *tx_cmd; __le16 fc; @@ -439,16 +897,9 @@ int iwl_mvm_tx_skb(struct iwl_mvm *mvm, struct sk_buff *skb, bool is_data_qos = false, is_ampdu = false; int hdrlen; - mvmsta = iwl_mvm_sta_from_mac80211(sta); fc = hdr->frame_control; hdrlen = ieee80211_hdrlen(fc); - if (WARN_ON_ONCE(!mvmsta)) - return -1; - - if (WARN_ON_ONCE(mvmsta->sta_id == IWL_MVM_STATION_COUNT)) - return -1; - dev_cmd = iwl_mvm_set_tx_params(mvm, skb, hdrlen, sta, mvmsta->sta_id); if (!dev_cmd) goto drop; @@ -521,6 +972,56 @@ drop: return -1; } +/* + * Sets the fields in the Tx cmd that are crypto related + */ +int iwl_mvm_tx_skb(struct iwl_mvm *mvm, struct sk_buff *skb, + struct ieee80211_sta *sta) +{ + struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta); + struct sk_buff_head mpdus_skbs; + unsigned int payload_len; + int ret = -1; + + if (WARN_ON_ONCE(!mvmsta)) + return -1; + + if (WARN_ON_ONCE(mvmsta->sta_id == IWL_MVM_STATION_COUNT)) + return -1; + + payload_len = skb_tail_pointer(skb) - skb_transport_header(skb) - + tcp_hdrlen(skb) + skb->data_len; + + /* This packet is smaller than MSS, one MPDU is enough */ + if (!skb_is_gso(skb) || payload_len <= skb_shinfo(skb)->gso_size) + return iwl_mvm_tx_mpdu(mvm, skb, sta); + + __skb_queue_head_init(&mpdus_skbs); + + ret = iwl_mvm_tx_tso(mvm, skb, sta, &mpdus_skbs); + if (ret) + goto out; + + if (WARN_ON(skb_queue_empty(&mpdus_skbs))) + goto out; + + while (!skb_queue_empty(&mpdus_skbs)) { + struct sk_buff *skb = __skb_dequeue(&mpdus_skbs); + + ret = iwl_mvm_tx_mpdu(mvm, skb, sta); + + if (ret) { + __skb_queue_purge(&mpdus_skbs); + goto out; + } + } + + ret = 0; + +out: + return ret ? -1 : 0; +} + static void iwl_mvm_check_ratid_empty(struct iwl_mvm *mvm, struct ieee80211_sta *sta, u8 tid) { -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
