[NETFILTER]: x_tables: simplify compat API
Split the xt_compat_match/xt_compat_target into smaller type-safe functions performing just one operation. Handle all alignment and size-related conversions centrally in these function instead of requiring each module to implement a full-blown conversion function. Replace ->compat callback by ->compat_from_user and ->compat_to_user callbacks, responsible for converting just a single private structure. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy
committed by
David S. Miller
David S. Miller
parent
79030ed07d
commit
9fa492cdc1
@ -942,73 +942,28 @@ static short compat_calc_jump(u_int16_t offset)
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return delta;
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}
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struct compat_ipt_standard_target
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static void compat_standard_from_user(void *dst, void *src)
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{
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struct compat_xt_entry_target target;
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compat_int_t verdict;
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};
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int v = *(compat_int_t *)src;
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struct compat_ipt_standard
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if (v > 0)
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v += compat_calc_jump(v);
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memcpy(dst, &v, sizeof(v));
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}
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static int compat_standard_to_user(void __user *dst, void *src)
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{
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struct compat_ipt_entry entry;
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struct compat_ipt_standard_target target;
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};
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compat_int_t cv = *(int *)src;
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#define IPT_ST_LEN XT_ALIGN(sizeof(struct ipt_standard_target))
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#define IPT_ST_COMPAT_LEN COMPAT_XT_ALIGN(sizeof(struct compat_ipt_standard_target))
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#define IPT_ST_OFFSET (IPT_ST_LEN - IPT_ST_COMPAT_LEN)
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static int compat_ipt_standard_fn(void *target,
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void **dstptr, int *size, int convert)
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{
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struct compat_ipt_standard_target compat_st, *pcompat_st;
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struct ipt_standard_target st, *pst;
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int ret;
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ret = 0;
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switch (convert) {
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case COMPAT_TO_USER:
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pst = target;
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memcpy(&compat_st.target, &pst->target,
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sizeof(compat_st.target));
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compat_st.verdict = pst->verdict;
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if (compat_st.verdict > 0)
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compat_st.verdict -=
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compat_calc_jump(compat_st.verdict);
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compat_st.target.u.user.target_size = IPT_ST_COMPAT_LEN;
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if (copy_to_user(*dstptr, &compat_st, IPT_ST_COMPAT_LEN))
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ret = -EFAULT;
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*size -= IPT_ST_OFFSET;
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*dstptr += IPT_ST_COMPAT_LEN;
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break;
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case COMPAT_FROM_USER:
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pcompat_st = target;
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memcpy(&st.target, &pcompat_st->target, IPT_ST_COMPAT_LEN);
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st.verdict = pcompat_st->verdict;
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if (st.verdict > 0)
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st.verdict += compat_calc_jump(st.verdict);
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st.target.u.user.target_size = IPT_ST_LEN;
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memcpy(*dstptr, &st, IPT_ST_LEN);
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*size += IPT_ST_OFFSET;
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*dstptr += IPT_ST_LEN;
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break;
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case COMPAT_CALC_SIZE:
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*size += IPT_ST_OFFSET;
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break;
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default:
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ret = -ENOPROTOOPT;
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break;
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}
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return ret;
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if (cv > 0)
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cv -= compat_calc_jump(cv);
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return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
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}
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static inline int
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compat_calc_match(struct ipt_entry_match *m, int * size)
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{
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if (m->u.kernel.match->compat)
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m->u.kernel.match->compat(m, NULL, size, COMPAT_CALC_SIZE);
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else
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xt_compat_match(m, NULL, size, COMPAT_CALC_SIZE);
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*size += xt_compat_match_offset(m->u.kernel.match);
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return 0;
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}
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@ -1023,10 +978,7 @@ static int compat_calc_entry(struct ipt_entry *e, struct xt_table_info *info,
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entry_offset = (void *)e - base;
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IPT_MATCH_ITERATE(e, compat_calc_match, &off);
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t = ipt_get_target(e);
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if (t->u.kernel.target->compat)
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t->u.kernel.target->compat(t, NULL, &off, COMPAT_CALC_SIZE);
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else
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xt_compat_target(t, NULL, &off, COMPAT_CALC_SIZE);
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off += xt_compat_target_offset(t->u.kernel.target);
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newinfo->size -= off;
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ret = compat_add_offset(entry_offset, off);
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if (ret)
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@ -1412,17 +1364,13 @@ struct compat_ipt_replace {
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};
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static inline int compat_copy_match_to_user(struct ipt_entry_match *m,
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void __user **dstptr, compat_uint_t *size)
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void * __user *dstptr, compat_uint_t *size)
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{
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if (m->u.kernel.match->compat)
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return m->u.kernel.match->compat(m, dstptr, size,
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COMPAT_TO_USER);
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else
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return xt_compat_match(m, dstptr, size, COMPAT_TO_USER);
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return xt_compat_match_to_user(m, dstptr, size);
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}
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static int compat_copy_entry_to_user(struct ipt_entry *e,
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void __user **dstptr, compat_uint_t *size)
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void * __user *dstptr, compat_uint_t *size)
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{
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struct ipt_entry_target __user *t;
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struct compat_ipt_entry __user *ce;
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@ -1442,11 +1390,7 @@ static int compat_copy_entry_to_user(struct ipt_entry *e,
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if (ret)
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goto out;
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t = ipt_get_target(e);
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if (t->u.kernel.target->compat)
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ret = t->u.kernel.target->compat(t, dstptr, size,
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COMPAT_TO_USER);
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else
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ret = xt_compat_target(t, dstptr, size, COMPAT_TO_USER);
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ret = xt_compat_target_to_user(t, dstptr, size);
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if (ret)
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goto out;
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ret = -EFAULT;
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@ -1478,11 +1422,7 @@ compat_check_calc_match(struct ipt_entry_match *m,
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return match ? PTR_ERR(match) : -ENOENT;
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}
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m->u.kernel.match = match;
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if (m->u.kernel.match->compat)
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m->u.kernel.match->compat(m, NULL, size, COMPAT_CALC_SIZE);
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else
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xt_compat_match(m, NULL, size, COMPAT_CALC_SIZE);
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*size += xt_compat_match_offset(match);
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(*i)++;
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return 0;
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@ -1543,10 +1483,7 @@ check_compat_entry_size_and_hooks(struct ipt_entry *e,
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}
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t->u.kernel.target = target;
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if (t->u.kernel.target->compat)
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t->u.kernel.target->compat(t, NULL, &off, COMPAT_CALC_SIZE);
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else
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xt_compat_target(t, NULL, &off, COMPAT_CALC_SIZE);
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off += xt_compat_target_offset(target);
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*size += off;
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ret = compat_add_offset(entry_offset, off);
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if (ret)
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@ -1584,10 +1521,7 @@ static inline int compat_copy_match_from_user(struct ipt_entry_match *m,
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dm = (struct ipt_entry_match *)*dstptr;
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match = m->u.kernel.match;
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if (match->compat)
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match->compat(m, dstptr, size, COMPAT_FROM_USER);
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else
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xt_compat_match(m, dstptr, size, COMPAT_FROM_USER);
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xt_compat_match_from_user(m, dstptr, size);
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ret = xt_check_match(match, AF_INET, dm->u.match_size - sizeof(*dm),
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name, hookmask, ip->proto,
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@ -1635,10 +1569,7 @@ static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr,
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de->target_offset = e->target_offset - (origsize - *size);
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t = ipt_get_target(e);
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target = t->u.kernel.target;
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if (target->compat)
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target->compat(t, dstptr, size, COMPAT_FROM_USER);
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else
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xt_compat_target(t, dstptr, size, COMPAT_FROM_USER);
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xt_compat_target_from_user(t, dstptr, size);
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de->next_offset = e->next_offset - (origsize - *size);
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for (h = 0; h < NF_IP_NUMHOOKS; h++) {
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@ -2205,7 +2136,9 @@ static struct ipt_target ipt_standard_target = {
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.targetsize = sizeof(int),
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.family = AF_INET,
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#ifdef CONFIG_COMPAT
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.compat = &compat_ipt_standard_fn,
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.compatsize = sizeof(compat_int_t),
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.compat_from_user = compat_standard_from_user,
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.compat_to_user = compat_standard_to_user,
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#endif
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};
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