From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- fs/afs/vl_list.c | 328 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 328 insertions(+) create mode 100644 fs/afs/vl_list.c (limited to 'fs/afs/vl_list.c') diff --git a/fs/afs/vl_list.c b/fs/afs/vl_list.c new file mode 100644 index 000000000..acc482161 --- /dev/null +++ b/fs/afs/vl_list.c @@ -0,0 +1,328 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* AFS vlserver list management. + * + * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include "internal.h" + +struct afs_vlserver *afs_alloc_vlserver(const char *name, size_t name_len, + unsigned short port) +{ + struct afs_vlserver *vlserver; + + vlserver = kzalloc(struct_size(vlserver, name, name_len + 1), + GFP_KERNEL); + if (vlserver) { + refcount_set(&vlserver->ref, 1); + rwlock_init(&vlserver->lock); + init_waitqueue_head(&vlserver->probe_wq); + spin_lock_init(&vlserver->probe_lock); + vlserver->rtt = UINT_MAX; + vlserver->name_len = name_len; + vlserver->port = port; + memcpy(vlserver->name, name, name_len); + } + return vlserver; +} + +static void afs_vlserver_rcu(struct rcu_head *rcu) +{ + struct afs_vlserver *vlserver = container_of(rcu, struct afs_vlserver, rcu); + + afs_put_addrlist(rcu_access_pointer(vlserver->addresses)); + kfree_rcu(vlserver, rcu); +} + +void afs_put_vlserver(struct afs_net *net, struct afs_vlserver *vlserver) +{ + if (vlserver && + refcount_dec_and_test(&vlserver->ref)) + call_rcu(&vlserver->rcu, afs_vlserver_rcu); +} + +struct afs_vlserver_list *afs_alloc_vlserver_list(unsigned int nr_servers) +{ + struct afs_vlserver_list *vllist; + + vllist = kzalloc(struct_size(vllist, servers, nr_servers), GFP_KERNEL); + if (vllist) { + refcount_set(&vllist->ref, 1); + rwlock_init(&vllist->lock); + } + + return vllist; +} + +void afs_put_vlserverlist(struct afs_net *net, struct afs_vlserver_list *vllist) +{ + if (vllist) { + if (refcount_dec_and_test(&vllist->ref)) { + int i; + + for (i = 0; i < vllist->nr_servers; i++) { + afs_put_vlserver(net, vllist->servers[i].server); + } + kfree_rcu(vllist, rcu); + } + } +} + +static u16 afs_extract_le16(const u8 **_b) +{ + u16 val; + + val = (u16)*(*_b)++ << 0; + val |= (u16)*(*_b)++ << 8; + return val; +} + +/* + * Build a VL server address list from a DNS queried server list. + */ +static struct afs_addr_list *afs_extract_vl_addrs(const u8 **_b, const u8 *end, + u8 nr_addrs, u16 port) +{ + struct afs_addr_list *alist; + const u8 *b = *_b; + int ret = -EINVAL; + + alist = afs_alloc_addrlist(nr_addrs, VL_SERVICE, port); + if (!alist) + return ERR_PTR(-ENOMEM); + if (nr_addrs == 0) + return alist; + + for (; nr_addrs > 0 && end - b >= nr_addrs; nr_addrs--) { + struct dns_server_list_v1_address hdr; + __be32 x[4]; + + hdr.address_type = *b++; + + switch (hdr.address_type) { + case DNS_ADDRESS_IS_IPV4: + if (end - b < 4) { + _leave(" = -EINVAL [short inet]"); + goto error; + } + memcpy(x, b, 4); + afs_merge_fs_addr4(alist, x[0], port); + b += 4; + break; + + case DNS_ADDRESS_IS_IPV6: + if (end - b < 16) { + _leave(" = -EINVAL [short inet6]"); + goto error; + } + memcpy(x, b, 16); + afs_merge_fs_addr6(alist, x, port); + b += 16; + break; + + default: + _leave(" = -EADDRNOTAVAIL [unknown af %u]", + hdr.address_type); + ret = -EADDRNOTAVAIL; + goto error; + } + } + + /* Start with IPv6 if available. */ + if (alist->nr_ipv4 < alist->nr_addrs) + alist->preferred = alist->nr_ipv4; + + *_b = b; + return alist; + +error: + *_b = b; + afs_put_addrlist(alist); + return ERR_PTR(ret); +} + +/* + * Build a VL server list from a DNS queried server list. + */ +struct afs_vlserver_list *afs_extract_vlserver_list(struct afs_cell *cell, + const void *buffer, + size_t buffer_size) +{ + const struct dns_server_list_v1_header *hdr = buffer; + struct dns_server_list_v1_server bs; + struct afs_vlserver_list *vllist, *previous; + struct afs_addr_list *addrs; + struct afs_vlserver *server; + const u8 *b = buffer, *end = buffer + buffer_size; + int ret = -ENOMEM, nr_servers, i, j; + + _enter(""); + + /* Check that it's a server list, v1 */ + if (end - b < sizeof(*hdr) || + hdr->hdr.content != DNS_PAYLOAD_IS_SERVER_LIST || + hdr->hdr.version != 1) { + pr_notice("kAFS: Got DNS record [%u,%u] len %zu\n", + hdr->hdr.content, hdr->hdr.version, end - b); + ret = -EDESTADDRREQ; + goto dump; + } + + nr_servers = hdr->nr_servers; + + vllist = afs_alloc_vlserver_list(nr_servers); + if (!vllist) + return ERR_PTR(-ENOMEM); + + vllist->source = (hdr->source < NR__dns_record_source) ? + hdr->source : NR__dns_record_source; + vllist->status = (hdr->status < NR__dns_lookup_status) ? + hdr->status : NR__dns_lookup_status; + + read_lock(&cell->vl_servers_lock); + previous = afs_get_vlserverlist( + rcu_dereference_protected(cell->vl_servers, + lockdep_is_held(&cell->vl_servers_lock))); + read_unlock(&cell->vl_servers_lock); + + b += sizeof(*hdr); + while (end - b >= sizeof(bs)) { + bs.name_len = afs_extract_le16(&b); + bs.priority = afs_extract_le16(&b); + bs.weight = afs_extract_le16(&b); + bs.port = afs_extract_le16(&b); + bs.source = *b++; + bs.status = *b++; + bs.protocol = *b++; + bs.nr_addrs = *b++; + + _debug("extract %u %u %u %u %u %u %*.*s", + bs.name_len, bs.priority, bs.weight, + bs.port, bs.protocol, bs.nr_addrs, + bs.name_len, bs.name_len, b); + + if (end - b < bs.name_len) + break; + + ret = -EPROTONOSUPPORT; + if (bs.protocol == DNS_SERVER_PROTOCOL_UNSPECIFIED) { + bs.protocol = DNS_SERVER_PROTOCOL_UDP; + } else if (bs.protocol != DNS_SERVER_PROTOCOL_UDP) { + _leave(" = [proto %u]", bs.protocol); + goto error; + } + + if (bs.port == 0) + bs.port = AFS_VL_PORT; + if (bs.source > NR__dns_record_source) + bs.source = NR__dns_record_source; + if (bs.status > NR__dns_lookup_status) + bs.status = NR__dns_lookup_status; + + /* See if we can update an old server record */ + server = NULL; + for (i = 0; i < previous->nr_servers; i++) { + struct afs_vlserver *p = previous->servers[i].server; + + if (p->name_len == bs.name_len && + p->port == bs.port && + strncasecmp(b, p->name, bs.name_len) == 0) { + server = afs_get_vlserver(p); + break; + } + } + + if (!server) { + ret = -ENOMEM; + server = afs_alloc_vlserver(b, bs.name_len, bs.port); + if (!server) + goto error; + } + + b += bs.name_len; + + /* Extract the addresses - note that we can't skip this as we + * have to advance the payload pointer. + */ + addrs = afs_extract_vl_addrs(&b, end, bs.nr_addrs, bs.port); + if (IS_ERR(addrs)) { + ret = PTR_ERR(addrs); + goto error_2; + } + + if (vllist->nr_servers >= nr_servers) { + _debug("skip %u >= %u", vllist->nr_servers, nr_servers); + afs_put_addrlist(addrs); + afs_put_vlserver(cell->net, server); + continue; + } + + addrs->source = bs.source; + addrs->status = bs.status; + + if (addrs->nr_addrs == 0) { + afs_put_addrlist(addrs); + if (!rcu_access_pointer(server->addresses)) { + afs_put_vlserver(cell->net, server); + continue; + } + } else { + struct afs_addr_list *old = addrs; + + write_lock(&server->lock); + old = rcu_replace_pointer(server->addresses, old, + lockdep_is_held(&server->lock)); + write_unlock(&server->lock); + afs_put_addrlist(old); + } + + + /* TODO: Might want to check for duplicates */ + + /* Insertion-sort by priority and weight */ + for (j = 0; j < vllist->nr_servers; j++) { + if (bs.priority < vllist->servers[j].priority) + break; /* Lower preferable */ + if (bs.priority == vllist->servers[j].priority && + bs.weight > vllist->servers[j].weight) + break; /* Higher preferable */ + } + + if (j < vllist->nr_servers) { + memmove(vllist->servers + j + 1, + vllist->servers + j, + (vllist->nr_servers - j) * sizeof(struct afs_vlserver_entry)); + } + + clear_bit(AFS_VLSERVER_FL_PROBED, &server->flags); + + vllist->servers[j].priority = bs.priority; + vllist->servers[j].weight = bs.weight; + vllist->servers[j].server = server; + vllist->nr_servers++; + } + + if (b != end) { + _debug("parse error %zd", b - end); + goto error; + } + + afs_put_vlserverlist(cell->net, previous); + _leave(" = ok [%u]", vllist->nr_servers); + return vllist; + +error_2: + afs_put_vlserver(cell->net, server); +error: + afs_put_vlserverlist(cell->net, vllist); + afs_put_vlserverlist(cell->net, previous); +dump: + if (ret != -ENOMEM) { + printk(KERN_DEBUG "DNS: at %zu\n", (const void *)b - buffer); + print_hex_dump_bytes("DNS: ", DUMP_PREFIX_NONE, buffer, buffer_size); + } + return ERR_PTR(ret); +} -- cgit v1.2.3