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-rw-r--r--net/dccp/ackvec.c100
1 files changed, 18 insertions, 82 deletions
diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c
index 85ad70cfba5b..de84dd34c93f 100644
--- a/net/dccp/ackvec.c
+++ b/net/dccp/ackvec.c
@@ -52,99 +52,35 @@ void dccp_ackvec_free(struct dccp_ackvec *av)
52 } 52 }
53} 53}
54 54
55static void dccp_ackvec_insert_avr(struct dccp_ackvec *av, 55/**
56 struct dccp_ackvec_record *avr) 56 * dccp_ackvec_update_records - Record information about sent Ack Vectors
57{ 57 * @av: Ack Vector records to update
58 /* 58 * @seqno: Sequence number of the packet carrying the Ack Vector just sent
59 * AVRs are sorted by seqno. Since we are sending them in order, we 59 * @nonce_sum: The sum of all buffer nonces contained in the Ack Vector
60 * just add the AVR at the head of the list. 60 */
61 * -sorbo. 61int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seqno, u8 nonce_sum)
62 */
63 if (!list_empty(&av->av_records)) {
64 const struct dccp_ackvec_record *head =
65 list_entry(av->av_records.next,
66 struct dccp_ackvec_record,
67 avr_node);
68 BUG_ON(before48(avr->avr_ack_seqno, head->avr_ack_seqno));
69 }
70
71 list_add(&avr->avr_node, &av->av_records);
72}
73
74int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
75{ 62{
76 struct dccp_sock *dp = dccp_sk(sk);
77 struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
78 /* Figure out how many options do we need to represent the ackvec */
79 const u8 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_SINGLE_OPT_MAXLEN);
80 u16 len = av->av_vec_len + 2 * nr_opts;
81 u8 i, nonce = 0;
82 const unsigned char *tail, *from;
83 unsigned char *to;
84 struct dccp_ackvec_record *avr; 63 struct dccp_ackvec_record *avr;
85 64
86 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
87 return -1;
88
89 avr = kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC); 65 avr = kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC);
90 if (avr == NULL) 66 if (avr == NULL)
91 return -1; 67 return -ENOBUFS;
92
93 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
94
95 to = skb_push(skb, len);
96 len = av->av_vec_len;
97 from = av->av_buf + av->av_buf_head;
98 tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;
99
100 for (i = 0; i < nr_opts; ++i) {
101 int copylen = len;
102
103 if (len > DCCP_SINGLE_OPT_MAXLEN)
104 copylen = DCCP_SINGLE_OPT_MAXLEN;
105
106 /*
107 * RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via
108 * its type; ack_nonce is the sum of all individual buf_nonce's.
109 */
110 nonce ^= av->av_buf_nonce[i];
111
112 *to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i];
113 *to++ = copylen + 2;
114
115 /* Check if buf_head wraps */
116 if (from + copylen > tail) {
117 const u16 tailsize = tail - from;
118
119 memcpy(to, from, tailsize);
120 to += tailsize;
121 len -= tailsize;
122 copylen -= tailsize;
123 from = av->av_buf;
124 }
125
126 memcpy(to, from, copylen);
127 from += copylen;
128 to += copylen;
129 len -= copylen;
130 }
131 68
132 /* 69 avr->avr_ack_seqno = seqno;
133 * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340.
134 */
135 avr->avr_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
136 avr->avr_ack_ptr = av->av_buf_head; 70 avr->avr_ack_ptr = av->av_buf_head;
137 avr->avr_ack_ackno = av->av_buf_ackno; 71 avr->avr_ack_ackno = av->av_buf_ackno;
138 avr->avr_ack_nonce = nonce; 72 avr->avr_ack_nonce = nonce_sum;
139 avr->avr_ack_runlen = dccp_ackvec_runlen(av->av_buf + av->av_buf_head); 73 avr->avr_ack_runlen = dccp_ackvec_runlen(av->av_buf + av->av_buf_head);
74 /*
75 * Since GSS is incremented for each packet, the list is automatically
76 * arranged in descending order of @ack_seqno.
77 */
78 list_add(&avr->avr_node, &av->av_records);
140 79
141 dccp_ackvec_insert_avr(av, avr); 80 dccp_pr_debug("Added Vector, ack_seqno=%llu, ack_ackno=%llu (rl=%u)\n",
142
143 dccp_pr_debug("%s ACK Vector 0, len=%d, ack_seqno=%llu, "
144 "ack_ackno=%llu\n",
145 dccp_role(sk), avr->avr_ack_runlen,
146 (unsigned long long)avr->avr_ack_seqno, 81 (unsigned long long)avr->avr_ack_seqno,
147 (unsigned long long)avr->avr_ack_ackno); 82 (unsigned long long)avr->avr_ack_ackno,
83 avr->avr_ack_runlen);
148 return 0; 84 return 0;
149} 85}
150 86