linux_dsm_epyc7002/net/nfc/netlink.c

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/*
* Copyright (C) 2011 Instituto Nokia de Tecnologia
*
* Authors:
* Lauro Ramos Venancio <lauro.venancio@openbossa.org>
* Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
*
* Vendor commands implementation based on net/wireless/nl80211.c
* which is:
*
* Copyright 2006-2010 Johannes Berg <johannes@sipsolutions.net>
* Copyright 2013-2014 Intel Mobile Communications GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
#include <net/genetlink.h>
#include <linux/nfc.h>
#include <linux/slab.h>
#include "nfc.h"
#include "llcp.h"
static const struct genl_multicast_group nfc_genl_mcgrps[] = {
{ .name = NFC_GENL_MCAST_EVENT_NAME, },
};
static struct genl_family nfc_genl_family;
static const struct nla_policy nfc_genl_policy[NFC_ATTR_MAX + 1] = {
[NFC_ATTR_DEVICE_INDEX] = { .type = NLA_U32 },
[NFC_ATTR_DEVICE_NAME] = { .type = NLA_STRING,
.len = NFC_DEVICE_NAME_MAXSIZE },
[NFC_ATTR_PROTOCOLS] = { .type = NLA_U32 },
[NFC_ATTR_COMM_MODE] = { .type = NLA_U8 },
[NFC_ATTR_RF_MODE] = { .type = NLA_U8 },
[NFC_ATTR_DEVICE_POWERED] = { .type = NLA_U8 },
[NFC_ATTR_IM_PROTOCOLS] = { .type = NLA_U32 },
[NFC_ATTR_TM_PROTOCOLS] = { .type = NLA_U32 },
[NFC_ATTR_LLC_PARAM_LTO] = { .type = NLA_U8 },
[NFC_ATTR_LLC_PARAM_RW] = { .type = NLA_U8 },
[NFC_ATTR_LLC_PARAM_MIUX] = { .type = NLA_U16 },
[NFC_ATTR_LLC_SDP] = { .type = NLA_NESTED },
[NFC_ATTR_FIRMWARE_NAME] = { .type = NLA_STRING,
.len = NFC_FIRMWARE_NAME_MAXSIZE },
[NFC_ATTR_SE_APDU] = { .type = NLA_BINARY },
[NFC_ATTR_VENDOR_DATA] = { .type = NLA_BINARY },
};
static const struct nla_policy nfc_sdp_genl_policy[NFC_SDP_ATTR_MAX + 1] = {
[NFC_SDP_ATTR_URI] = { .type = NLA_STRING,
.len = U8_MAX - 4 },
[NFC_SDP_ATTR_SAP] = { .type = NLA_U8 },
};
static int nfc_genl_send_target(struct sk_buff *msg, struct nfc_target *target,
struct netlink_callback *cb, int flags)
{
void *hdr;
hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
&nfc_genl_family, flags, NFC_CMD_GET_TARGET);
if (!hdr)
return -EMSGSIZE;
genl_dump_check_consistent(cb, hdr);
if (nla_put_u32(msg, NFC_ATTR_TARGET_INDEX, target->idx) ||
nla_put_u32(msg, NFC_ATTR_PROTOCOLS, target->supported_protocols) ||
nla_put_u16(msg, NFC_ATTR_TARGET_SENS_RES, target->sens_res) ||
nla_put_u8(msg, NFC_ATTR_TARGET_SEL_RES, target->sel_res))
goto nla_put_failure;
if (target->nfcid1_len > 0 &&
nla_put(msg, NFC_ATTR_TARGET_NFCID1, target->nfcid1_len,
target->nfcid1))
goto nla_put_failure;
if (target->sensb_res_len > 0 &&
nla_put(msg, NFC_ATTR_TARGET_SENSB_RES, target->sensb_res_len,
target->sensb_res))
goto nla_put_failure;
if (target->sensf_res_len > 0 &&
nla_put(msg, NFC_ATTR_TARGET_SENSF_RES, target->sensf_res_len,
target->sensf_res))
goto nla_put_failure;
if (target->is_iso15693) {
if (nla_put_u8(msg, NFC_ATTR_TARGET_ISO15693_DSFID,
target->iso15693_dsfid) ||
nla_put(msg, NFC_ATTR_TARGET_ISO15693_UID,
sizeof(target->iso15693_uid), target->iso15693_uid))
goto nla_put_failure;
}
netlink: make nlmsg_end() and genlmsg_end() void Contrary to common expectations for an "int" return, these functions return only a positive value -- if used correctly they cannot even return 0 because the message header will necessarily be in the skb. This makes the very common pattern of if (genlmsg_end(...) < 0) { ... } be a whole bunch of dead code. Many places also simply do return nlmsg_end(...); and the caller is expected to deal with it. This also commonly (at least for me) causes errors, because it is very common to write if (my_function(...)) /* error condition */ and if my_function() does "return nlmsg_end()" this is of course wrong. Additionally, there's not a single place in the kernel that actually needs the message length returned, and if anyone needs it later then it'll be very easy to just use skb->len there. Remove this, and make the functions void. This removes a bunch of dead code as described above. The patch adds lines because I did - return nlmsg_end(...); + nlmsg_end(...); + return 0; I could have preserved all the function's return values by returning skb->len, but instead I've audited all the places calling the affected functions and found that none cared. A few places actually compared the return value with <= 0 in dump functionality, but that could just be changed to < 0 with no change in behaviour, so I opted for the more efficient version. One instance of the error I've made numerous times now is also present in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't check for <0 or <=0 and thus broke out of the loop every single time. I've preserved this since it will (I think) have caused the messages to userspace to be formatted differently with just a single message for every SKB returned to userspace. It's possible that this isn't needed for the tools that actually use this, but I don't even know what they are so couldn't test that changing this behaviour would be acceptable. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-17 04:09:00 +07:00
genlmsg_end(msg, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
static struct nfc_dev *__get_device_from_cb(struct netlink_callback *cb)
{
struct nlattr **attrbuf = genl_family_attrbuf(&nfc_genl_family);
struct nfc_dev *dev;
int rc;
u32 idx;
netlink: make validation more configurable for future strictness We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 19:07:28 +07:00
rc = nlmsg_parse_deprecated(cb->nlh,
GENL_HDRLEN + nfc_genl_family.hdrsize,
attrbuf, nfc_genl_family.maxattr,
nfc_genl_policy, NULL);
if (rc < 0)
return ERR_PTR(rc);
if (!attrbuf[NFC_ATTR_DEVICE_INDEX])
return ERR_PTR(-EINVAL);
idx = nla_get_u32(attrbuf[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return ERR_PTR(-ENODEV);
return dev;
}
static int nfc_genl_dump_targets(struct sk_buff *skb,
struct netlink_callback *cb)
{
int i = cb->args[0];
struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
int rc;
if (!dev) {
dev = __get_device_from_cb(cb);
if (IS_ERR(dev))
return PTR_ERR(dev);
cb->args[1] = (long) dev;
}
device_lock(&dev->dev);
cb->seq = dev->targets_generation;
while (i < dev->n_targets) {
rc = nfc_genl_send_target(skb, &dev->targets[i], cb,
NLM_F_MULTI);
if (rc < 0)
break;
i++;
}
device_unlock(&dev->dev);
cb->args[0] = i;
return skb->len;
}
static int nfc_genl_dump_targets_done(struct netlink_callback *cb)
{
struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
if (dev)
nfc_put_device(dev);
return 0;
}
int nfc_genl_targets_found(struct nfc_dev *dev)
{
struct sk_buff *msg;
void *hdr;
dev->genl_data.poll_req_portid = 0;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_TARGETS_FOUND);
if (!hdr)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
goto nla_put_failure;
genlmsg_end(msg, hdr);
return genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_ATOMIC);
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
int nfc_genl_target_lost(struct nfc_dev *dev, u32 target_idx)
{
struct sk_buff *msg;
void *hdr;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_TARGET_LOST);
if (!hdr)
goto free_msg;
if (nla_put_string(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev)) ||
nla_put_u32(msg, NFC_ATTR_TARGET_INDEX, target_idx))
goto nla_put_failure;
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
return 0;
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
int nfc_genl_tm_activated(struct nfc_dev *dev, u32 protocol)
{
struct sk_buff *msg;
void *hdr;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_TM_ACTIVATED);
if (!hdr)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
goto nla_put_failure;
if (nla_put_u32(msg, NFC_ATTR_TM_PROTOCOLS, protocol))
goto nla_put_failure;
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
return 0;
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
int nfc_genl_tm_deactivated(struct nfc_dev *dev)
{
struct sk_buff *msg;
void *hdr;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_TM_DEACTIVATED);
if (!hdr)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
goto nla_put_failure;
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
return 0;
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
static int nfc_genl_setup_device_added(struct nfc_dev *dev, struct sk_buff *msg)
{
if (nla_put_string(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev)) ||
nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx) ||
nla_put_u32(msg, NFC_ATTR_PROTOCOLS, dev->supported_protocols) ||
nla_put_u8(msg, NFC_ATTR_DEVICE_POWERED, dev->dev_up) ||
nla_put_u8(msg, NFC_ATTR_RF_MODE, dev->rf_mode))
return -1;
return 0;
}
int nfc_genl_device_added(struct nfc_dev *dev)
{
struct sk_buff *msg;
void *hdr;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_DEVICE_ADDED);
if (!hdr)
goto free_msg;
if (nfc_genl_setup_device_added(dev, msg))
goto nla_put_failure;
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
return 0;
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
int nfc_genl_device_removed(struct nfc_dev *dev)
{
struct sk_buff *msg;
void *hdr;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_DEVICE_REMOVED);
if (!hdr)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
goto nla_put_failure;
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
return 0;
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
int nfc_genl_llc_send_sdres(struct nfc_dev *dev, struct hlist_head *sdres_list)
{
struct sk_buff *msg;
struct nlattr *sdp_attr, *uri_attr;
struct nfc_llcp_sdp_tlv *sdres;
struct hlist_node *n;
void *hdr;
int rc = -EMSGSIZE;
int i;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_LLC_SDRES);
if (!hdr)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
goto nla_put_failure;
sdp_attr = nla_nest_start_noflag(msg, NFC_ATTR_LLC_SDP);
if (sdp_attr == NULL) {
rc = -ENOMEM;
goto nla_put_failure;
}
i = 1;
hlist_for_each_entry_safe(sdres, n, sdres_list, node) {
pr_debug("uri: %s, sap: %d\n", sdres->uri, sdres->sap);
uri_attr = nla_nest_start_noflag(msg, i++);
if (uri_attr == NULL) {
rc = -ENOMEM;
goto nla_put_failure;
}
if (nla_put_u8(msg, NFC_SDP_ATTR_SAP, sdres->sap))
goto nla_put_failure;
if (nla_put_string(msg, NFC_SDP_ATTR_URI, sdres->uri))
goto nla_put_failure;
nla_nest_end(msg, uri_attr);
hlist_del(&sdres->node);
nfc_llcp_free_sdp_tlv(sdres);
}
nla_nest_end(msg, sdp_attr);
genlmsg_end(msg, hdr);
return genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_ATOMIC);
nla_put_failure:
free_msg:
nlmsg_free(msg);
nfc_llcp_free_sdp_tlv_list(sdres_list);
return rc;
}
int nfc_genl_se_added(struct nfc_dev *dev, u32 se_idx, u16 type)
{
struct sk_buff *msg;
void *hdr;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_SE_ADDED);
if (!hdr)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx) ||
nla_put_u32(msg, NFC_ATTR_SE_INDEX, se_idx) ||
nla_put_u8(msg, NFC_ATTR_SE_TYPE, type))
goto nla_put_failure;
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
return 0;
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
int nfc_genl_se_removed(struct nfc_dev *dev, u32 se_idx)
{
struct sk_buff *msg;
void *hdr;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_SE_REMOVED);
if (!hdr)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx) ||
nla_put_u32(msg, NFC_ATTR_SE_INDEX, se_idx))
goto nla_put_failure;
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
return 0;
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
int nfc_genl_se_transaction(struct nfc_dev *dev, u8 se_idx,
struct nfc_evt_transaction *evt_transaction)
{
struct nfc_se *se;
struct sk_buff *msg;
void *hdr;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_SE_TRANSACTION);
if (!hdr)
goto free_msg;
se = nfc_find_se(dev, se_idx);
if (!se)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx) ||
nla_put_u32(msg, NFC_ATTR_SE_INDEX, se_idx) ||
nla_put_u8(msg, NFC_ATTR_SE_TYPE, se->type) ||
nla_put(msg, NFC_ATTR_SE_AID, evt_transaction->aid_len,
evt_transaction->aid) ||
nla_put(msg, NFC_ATTR_SE_PARAMS, evt_transaction->params_len,
evt_transaction->params))
goto nla_put_failure;
/* evt_transaction is no more used */
devm_kfree(&dev->dev, evt_transaction);
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
return 0;
nla_put_failure:
free_msg:
/* evt_transaction is no more used */
devm_kfree(&dev->dev, evt_transaction);
nlmsg_free(msg);
return -EMSGSIZE;
}
int nfc_genl_se_connectivity(struct nfc_dev *dev, u8 se_idx)
{
struct nfc_se *se;
struct sk_buff *msg;
void *hdr;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_EVENT_SE_CONNECTIVITY);
if (!hdr)
goto free_msg;
se = nfc_find_se(dev, se_idx);
if (!se)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx) ||
nla_put_u32(msg, NFC_ATTR_SE_INDEX, se_idx) ||
nla_put_u8(msg, NFC_ATTR_SE_TYPE, se->type))
goto nla_put_failure;
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
return 0;
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
static int nfc_genl_send_device(struct sk_buff *msg, struct nfc_dev *dev,
u32 portid, u32 seq,
struct netlink_callback *cb,
int flags)
{
void *hdr;
hdr = genlmsg_put(msg, portid, seq, &nfc_genl_family, flags,
NFC_CMD_GET_DEVICE);
if (!hdr)
return -EMSGSIZE;
if (cb)
genl_dump_check_consistent(cb, hdr);
if (nfc_genl_setup_device_added(dev, msg))
goto nla_put_failure;
netlink: make nlmsg_end() and genlmsg_end() void Contrary to common expectations for an "int" return, these functions return only a positive value -- if used correctly they cannot even return 0 because the message header will necessarily be in the skb. This makes the very common pattern of if (genlmsg_end(...) < 0) { ... } be a whole bunch of dead code. Many places also simply do return nlmsg_end(...); and the caller is expected to deal with it. This also commonly (at least for me) causes errors, because it is very common to write if (my_function(...)) /* error condition */ and if my_function() does "return nlmsg_end()" this is of course wrong. Additionally, there's not a single place in the kernel that actually needs the message length returned, and if anyone needs it later then it'll be very easy to just use skb->len there. Remove this, and make the functions void. This removes a bunch of dead code as described above. The patch adds lines because I did - return nlmsg_end(...); + nlmsg_end(...); + return 0; I could have preserved all the function's return values by returning skb->len, but instead I've audited all the places calling the affected functions and found that none cared. A few places actually compared the return value with <= 0 in dump functionality, but that could just be changed to < 0 with no change in behaviour, so I opted for the more efficient version. One instance of the error I've made numerous times now is also present in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't check for <0 or <=0 and thus broke out of the loop every single time. I've preserved this since it will (I think) have caused the messages to userspace to be formatted differently with just a single message for every SKB returned to userspace. It's possible that this isn't needed for the tools that actually use this, but I don't even know what they are so couldn't test that changing this behaviour would be acceptable. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-17 04:09:00 +07:00
genlmsg_end(msg, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
static int nfc_genl_dump_devices(struct sk_buff *skb,
struct netlink_callback *cb)
{
struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];
struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
bool first_call = false;
if (!iter) {
first_call = true;
iter = kmalloc(sizeof(struct class_dev_iter), GFP_KERNEL);
if (!iter)
return -ENOMEM;
cb->args[0] = (long) iter;
}
mutex_lock(&nfc_devlist_mutex);
cb->seq = nfc_devlist_generation;
if (first_call) {
nfc_device_iter_init(iter);
dev = nfc_device_iter_next(iter);
}
while (dev) {
int rc;
rc = nfc_genl_send_device(skb, dev, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, cb, NLM_F_MULTI);
if (rc < 0)
break;
dev = nfc_device_iter_next(iter);
}
mutex_unlock(&nfc_devlist_mutex);
cb->args[1] = (long) dev;
return skb->len;
}
static int nfc_genl_dump_devices_done(struct netlink_callback *cb)
{
struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];
nfc_device_iter_exit(iter);
kfree(iter);
return 0;
}
int nfc_genl_dep_link_up_event(struct nfc_dev *dev, u32 target_idx,
u8 comm_mode, u8 rf_mode)
{
struct sk_buff *msg;
void *hdr;
pr_debug("DEP link is up\n");
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0, NFC_CMD_DEP_LINK_UP);
if (!hdr)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
goto nla_put_failure;
if (rf_mode == NFC_RF_INITIATOR &&
nla_put_u32(msg, NFC_ATTR_TARGET_INDEX, target_idx))
goto nla_put_failure;
if (nla_put_u8(msg, NFC_ATTR_COMM_MODE, comm_mode) ||
nla_put_u8(msg, NFC_ATTR_RF_MODE, rf_mode))
goto nla_put_failure;
genlmsg_end(msg, hdr);
dev->dep_link_up = true;
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_ATOMIC);
return 0;
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
int nfc_genl_dep_link_down_event(struct nfc_dev *dev)
{
struct sk_buff *msg;
void *hdr;
pr_debug("DEP link is down\n");
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_CMD_DEP_LINK_DOWN);
if (!hdr)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
goto nla_put_failure;
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_ATOMIC);
return 0;
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
static int nfc_genl_get_device(struct sk_buff *skb, struct genl_info *info)
{
struct sk_buff *msg;
struct nfc_dev *dev;
u32 idx;
int rc = -ENOBUFS;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg) {
rc = -ENOMEM;
goto out_putdev;
}
rc = nfc_genl_send_device(msg, dev, info->snd_portid, info->snd_seq,
NULL, 0);
if (rc < 0)
goto out_free;
nfc_put_device(dev);
return genlmsg_reply(msg, info);
out_free:
nlmsg_free(msg);
out_putdev:
nfc_put_device(dev);
return rc;
}
static int nfc_genl_dev_up(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
int rc;
u32 idx;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
rc = nfc_dev_up(dev);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_dev_down(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
int rc;
u32 idx;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
rc = nfc_dev_down(dev);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_start_poll(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
int rc;
u32 idx;
u32 im_protocols = 0, tm_protocols = 0;
pr_debug("Poll start\n");
if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
((!info->attrs[NFC_ATTR_IM_PROTOCOLS] &&
!info->attrs[NFC_ATTR_PROTOCOLS]) &&
!info->attrs[NFC_ATTR_TM_PROTOCOLS]))
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
if (info->attrs[NFC_ATTR_TM_PROTOCOLS])
tm_protocols = nla_get_u32(info->attrs[NFC_ATTR_TM_PROTOCOLS]);
if (info->attrs[NFC_ATTR_IM_PROTOCOLS])
im_protocols = nla_get_u32(info->attrs[NFC_ATTR_IM_PROTOCOLS]);
else if (info->attrs[NFC_ATTR_PROTOCOLS])
im_protocols = nla_get_u32(info->attrs[NFC_ATTR_PROTOCOLS]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
mutex_lock(&dev->genl_data.genl_data_mutex);
rc = nfc_start_poll(dev, im_protocols, tm_protocols);
if (!rc)
dev->genl_data.poll_req_portid = info->snd_portid;
mutex_unlock(&dev->genl_data.genl_data_mutex);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_stop_poll(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
int rc;
u32 idx;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
device_lock(&dev->dev);
if (!dev->polling) {
device_unlock(&dev->dev);
return -EINVAL;
}
device_unlock(&dev->dev);
mutex_lock(&dev->genl_data.genl_data_mutex);
if (dev->genl_data.poll_req_portid != info->snd_portid) {
rc = -EBUSY;
goto out;
}
rc = nfc_stop_poll(dev);
dev->genl_data.poll_req_portid = 0;
out:
mutex_unlock(&dev->genl_data.genl_data_mutex);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_activate_target(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
u32 device_idx, target_idx, protocol;
int rc;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
!info->attrs[NFC_ATTR_TARGET_INDEX] ||
!info->attrs[NFC_ATTR_PROTOCOLS])
return -EINVAL;
device_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(device_idx);
if (!dev)
return -ENODEV;
target_idx = nla_get_u32(info->attrs[NFC_ATTR_TARGET_INDEX]);
protocol = nla_get_u32(info->attrs[NFC_ATTR_PROTOCOLS]);
nfc_deactivate_target(dev, target_idx, NFC_TARGET_MODE_SLEEP);
rc = nfc_activate_target(dev, target_idx, protocol);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_deactivate_target(struct sk_buff *skb,
struct genl_info *info)
{
struct nfc_dev *dev;
u32 device_idx, target_idx;
int rc;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
return -EINVAL;
device_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(device_idx);
if (!dev)
return -ENODEV;
target_idx = nla_get_u32(info->attrs[NFC_ATTR_TARGET_INDEX]);
rc = nfc_deactivate_target(dev, target_idx, NFC_TARGET_MODE_SLEEP);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_dep_link_up(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
int rc, tgt_idx;
u32 idx;
u8 comm;
pr_debug("DEP link up\n");
if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
!info->attrs[NFC_ATTR_COMM_MODE])
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
if (!info->attrs[NFC_ATTR_TARGET_INDEX])
tgt_idx = NFC_TARGET_IDX_ANY;
else
tgt_idx = nla_get_u32(info->attrs[NFC_ATTR_TARGET_INDEX]);
comm = nla_get_u8(info->attrs[NFC_ATTR_COMM_MODE]);
if (comm != NFC_COMM_ACTIVE && comm != NFC_COMM_PASSIVE)
return -EINVAL;
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
rc = nfc_dep_link_up(dev, tgt_idx, comm);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_dep_link_down(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
int rc;
u32 idx;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
rc = nfc_dep_link_down(dev);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_send_params(struct sk_buff *msg,
struct nfc_llcp_local *local,
u32 portid, u32 seq)
{
void *hdr;
hdr = genlmsg_put(msg, portid, seq, &nfc_genl_family, 0,
NFC_CMD_LLC_GET_PARAMS);
if (!hdr)
return -EMSGSIZE;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, local->dev->idx) ||
nla_put_u8(msg, NFC_ATTR_LLC_PARAM_LTO, local->lto) ||
nla_put_u8(msg, NFC_ATTR_LLC_PARAM_RW, local->rw) ||
nla_put_u16(msg, NFC_ATTR_LLC_PARAM_MIUX, be16_to_cpu(local->miux)))
goto nla_put_failure;
netlink: make nlmsg_end() and genlmsg_end() void Contrary to common expectations for an "int" return, these functions return only a positive value -- if used correctly they cannot even return 0 because the message header will necessarily be in the skb. This makes the very common pattern of if (genlmsg_end(...) < 0) { ... } be a whole bunch of dead code. Many places also simply do return nlmsg_end(...); and the caller is expected to deal with it. This also commonly (at least for me) causes errors, because it is very common to write if (my_function(...)) /* error condition */ and if my_function() does "return nlmsg_end()" this is of course wrong. Additionally, there's not a single place in the kernel that actually needs the message length returned, and if anyone needs it later then it'll be very easy to just use skb->len there. Remove this, and make the functions void. This removes a bunch of dead code as described above. The patch adds lines because I did - return nlmsg_end(...); + nlmsg_end(...); + return 0; I could have preserved all the function's return values by returning skb->len, but instead I've audited all the places calling the affected functions and found that none cared. A few places actually compared the return value with <= 0 in dump functionality, but that could just be changed to < 0 with no change in behaviour, so I opted for the more efficient version. One instance of the error I've made numerous times now is also present in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't check for <0 or <=0 and thus broke out of the loop every single time. I've preserved this since it will (I think) have caused the messages to userspace to be formatted differently with just a single message for every SKB returned to userspace. It's possible that this isn't needed for the tools that actually use this, but I don't even know what they are so couldn't test that changing this behaviour would be acceptable. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-17 04:09:00 +07:00
genlmsg_end(msg, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
static int nfc_genl_llc_get_params(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
struct nfc_llcp_local *local;
int rc = 0;
struct sk_buff *msg = NULL;
u32 idx;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
device_lock(&dev->dev);
local = nfc_llcp_find_local(dev);
if (!local) {
rc = -ENODEV;
goto exit;
}
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg) {
rc = -ENOMEM;
goto exit;
}
rc = nfc_genl_send_params(msg, local, info->snd_portid, info->snd_seq);
exit:
device_unlock(&dev->dev);
nfc_put_device(dev);
if (rc < 0) {
if (msg)
nlmsg_free(msg);
return rc;
}
return genlmsg_reply(msg, info);
}
static int nfc_genl_llc_set_params(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
struct nfc_llcp_local *local;
u8 rw = 0;
u16 miux = 0;
u32 idx;
int rc = 0;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
(!info->attrs[NFC_ATTR_LLC_PARAM_LTO] &&
!info->attrs[NFC_ATTR_LLC_PARAM_RW] &&
!info->attrs[NFC_ATTR_LLC_PARAM_MIUX]))
return -EINVAL;
if (info->attrs[NFC_ATTR_LLC_PARAM_RW]) {
rw = nla_get_u8(info->attrs[NFC_ATTR_LLC_PARAM_RW]);
if (rw > LLCP_MAX_RW)
return -EINVAL;
}
if (info->attrs[NFC_ATTR_LLC_PARAM_MIUX]) {
miux = nla_get_u16(info->attrs[NFC_ATTR_LLC_PARAM_MIUX]);
if (miux > LLCP_MAX_MIUX)
return -EINVAL;
}
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
device_lock(&dev->dev);
local = nfc_llcp_find_local(dev);
if (!local) {
nfc_put_device(dev);
rc = -ENODEV;
goto exit;
}
if (info->attrs[NFC_ATTR_LLC_PARAM_LTO]) {
if (dev->dep_link_up) {
rc = -EINPROGRESS;
goto exit;
}
local->lto = nla_get_u8(info->attrs[NFC_ATTR_LLC_PARAM_LTO]);
}
if (info->attrs[NFC_ATTR_LLC_PARAM_RW])
local->rw = rw;
if (info->attrs[NFC_ATTR_LLC_PARAM_MIUX])
local->miux = cpu_to_be16(miux);
exit:
device_unlock(&dev->dev);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_llc_sdreq(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
struct nfc_llcp_local *local;
struct nlattr *attr, *sdp_attrs[NFC_SDP_ATTR_MAX+1];
u32 idx;
u8 tid;
char *uri;
int rc = 0, rem;
size_t uri_len, tlvs_len;
struct hlist_head sdreq_list;
struct nfc_llcp_sdp_tlv *sdreq;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
!info->attrs[NFC_ATTR_LLC_SDP])
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
device_lock(&dev->dev);
if (dev->dep_link_up == false) {
rc = -ENOLINK;
goto exit;
}
local = nfc_llcp_find_local(dev);
if (!local) {
nfc_put_device(dev);
rc = -ENODEV;
goto exit;
}
INIT_HLIST_HEAD(&sdreq_list);
tlvs_len = 0;
nla_for_each_nested(attr, info->attrs[NFC_ATTR_LLC_SDP], rem) {
netlink: make validation more configurable for future strictness We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 19:07:28 +07:00
rc = nla_parse_nested_deprecated(sdp_attrs, NFC_SDP_ATTR_MAX,
attr, nfc_sdp_genl_policy,
info->extack);
if (rc != 0) {
rc = -EINVAL;
goto exit;
}
if (!sdp_attrs[NFC_SDP_ATTR_URI])
continue;
uri_len = nla_len(sdp_attrs[NFC_SDP_ATTR_URI]);
if (uri_len == 0)
continue;
uri = nla_data(sdp_attrs[NFC_SDP_ATTR_URI]);
if (uri == NULL || *uri == 0)
continue;
tid = local->sdreq_next_tid++;
sdreq = nfc_llcp_build_sdreq_tlv(tid, uri, uri_len);
if (sdreq == NULL) {
rc = -ENOMEM;
goto exit;
}
tlvs_len += sdreq->tlv_len;
hlist_add_head(&sdreq->node, &sdreq_list);
}
if (hlist_empty(&sdreq_list)) {
rc = -EINVAL;
goto exit;
}
rc = nfc_llcp_send_snl_sdreq(local, &sdreq_list, tlvs_len);
exit:
device_unlock(&dev->dev);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_fw_download(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
int rc;
u32 idx;
char firmware_name[NFC_FIRMWARE_NAME_MAXSIZE + 1];
if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
nla_strlcpy(firmware_name, info->attrs[NFC_ATTR_FIRMWARE_NAME],
sizeof(firmware_name));
rc = nfc_fw_download(dev, firmware_name);
nfc_put_device(dev);
return rc;
}
int nfc_genl_fw_download_done(struct nfc_dev *dev, const char *firmware_name,
u32 result)
{
struct sk_buff *msg;
void *hdr;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_CMD_FW_DOWNLOAD);
if (!hdr)
goto free_msg;
if (nla_put_string(msg, NFC_ATTR_FIRMWARE_NAME, firmware_name) ||
nla_put_u32(msg, NFC_ATTR_FIRMWARE_DOWNLOAD_STATUS, result) ||
nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
goto nla_put_failure;
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
return 0;
nla_put_failure:
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}
static int nfc_genl_enable_se(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
int rc;
u32 idx, se_idx;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
!info->attrs[NFC_ATTR_SE_INDEX])
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
se_idx = nla_get_u32(info->attrs[NFC_ATTR_SE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
rc = nfc_enable_se(dev, se_idx);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_disable_se(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
int rc;
u32 idx, se_idx;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
!info->attrs[NFC_ATTR_SE_INDEX])
return -EINVAL;
idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
se_idx = nla_get_u32(info->attrs[NFC_ATTR_SE_INDEX]);
dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;
rc = nfc_disable_se(dev, se_idx);
nfc_put_device(dev);
return rc;
}
static int nfc_genl_send_se(struct sk_buff *msg, struct nfc_dev *dev,
u32 portid, u32 seq,
struct netlink_callback *cb,
int flags)
{
void *hdr;
struct nfc_se *se, *n;
list_for_each_entry_safe(se, n, &dev->secure_elements, list) {
hdr = genlmsg_put(msg, portid, seq, &nfc_genl_family, flags,
NFC_CMD_GET_SE);
if (!hdr)
goto nla_put_failure;
if (cb)
genl_dump_check_consistent(cb, hdr);
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx) ||
nla_put_u32(msg, NFC_ATTR_SE_INDEX, se->idx) ||
nla_put_u8(msg, NFC_ATTR_SE_TYPE, se->type))
goto nla_put_failure;
netlink: make nlmsg_end() and genlmsg_end() void Contrary to common expectations for an "int" return, these functions return only a positive value -- if used correctly they cannot even return 0 because the message header will necessarily be in the skb. This makes the very common pattern of if (genlmsg_end(...) < 0) { ... } be a whole bunch of dead code. Many places also simply do return nlmsg_end(...); and the caller is expected to deal with it. This also commonly (at least for me) causes errors, because it is very common to write if (my_function(...)) /* error condition */ and if my_function() does "return nlmsg_end()" this is of course wrong. Additionally, there's not a single place in the kernel that actually needs the message length returned, and if anyone needs it later then it'll be very easy to just use skb->len there. Remove this, and make the functions void. This removes a bunch of dead code as described above. The patch adds lines because I did - return nlmsg_end(...); + nlmsg_end(...); + return 0; I could have preserved all the function's return values by returning skb->len, but instead I've audited all the places calling the affected functions and found that none cared. A few places actually compared the return value with <= 0 in dump functionality, but that could just be changed to < 0 with no change in behaviour, so I opted for the more efficient version. One instance of the error I've made numerous times now is also present in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't check for <0 or <=0 and thus broke out of the loop every single time. I've preserved this since it will (I think) have caused the messages to userspace to be formatted differently with just a single message for every SKB returned to userspace. It's possible that this isn't needed for the tools that actually use this, but I don't even know what they are so couldn't test that changing this behaviour would be acceptable. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-17 04:09:00 +07:00
genlmsg_end(msg, hdr);
}
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
static int nfc_genl_dump_ses(struct sk_buff *skb,
struct netlink_callback *cb)
{
struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];
struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
bool first_call = false;
if (!iter) {
first_call = true;
iter = kmalloc(sizeof(struct class_dev_iter), GFP_KERNEL);
if (!iter)
return -ENOMEM;
cb->args[0] = (long) iter;
}
mutex_lock(&nfc_devlist_mutex);
cb->seq = nfc_devlist_generation;
if (first_call) {
nfc_device_iter_init(iter);
dev = nfc_device_iter_next(iter);
}
while (dev) {
int rc;
rc = nfc_genl_send_se(skb, dev, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, cb, NLM_F_MULTI);
if (rc < 0)
break;
dev = nfc_device_iter_next(iter);
}
mutex_unlock(&nfc_devlist_mutex);
cb->args[1] = (long) dev;
return skb->len;
}
static int nfc_genl_dump_ses_done(struct netlink_callback *cb)
{
struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];
nfc_device_iter_exit(iter);
kfree(iter);
return 0;
}
static int nfc_se_io(struct nfc_dev *dev, u32 se_idx,
u8 *apdu, size_t apdu_length,
se_io_cb_t cb, void *cb_context)
{
struct nfc_se *se;
int rc;
pr_debug("%s se index %d\n", dev_name(&dev->dev), se_idx);
device_lock(&dev->dev);
if (!device_is_registered(&dev->dev)) {
rc = -ENODEV;
goto error;
}
if (!dev->dev_up) {
rc = -ENODEV;
goto error;
}
if (!dev->ops->se_io) {
rc = -EOPNOTSUPP;
goto error;
}
se = nfc_find_se(dev, se_idx);
if (!se) {
rc = -EINVAL;
goto error;
}
if (se->state != NFC_SE_ENABLED) {
rc = -ENODEV;
goto error;
}
rc = dev->ops->se_io(dev, se_idx, apdu,
apdu_length, cb, cb_context);
error:
device_unlock(&dev->dev);
return rc;
}
struct se_io_ctx {
u32 dev_idx;
u32 se_idx;
};
static void se_io_cb(void *context, u8 *apdu, size_t apdu_len, int err)
{
struct se_io_ctx *ctx = context;
struct sk_buff *msg;
void *hdr;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg) {
kfree(ctx);
return;
}
hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_CMD_SE_IO);
if (!hdr)
goto free_msg;
if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, ctx->dev_idx) ||
nla_put_u32(msg, NFC_ATTR_SE_INDEX, ctx->se_idx) ||
nla_put(msg, NFC_ATTR_SE_APDU, apdu_len, apdu))
goto nla_put_failure;
genlmsg_end(msg, hdr);
genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
kfree(ctx);
return;
nla_put_failure:
free_msg:
nlmsg_free(msg);
kfree(ctx);
return;
}
static int nfc_genl_se_io(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
struct se_io_ctx *ctx;
u32 dev_idx, se_idx;
u8 *apdu;
size_t apdu_len;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
!info->attrs[NFC_ATTR_SE_INDEX] ||
!info->attrs[NFC_ATTR_SE_APDU])
return -EINVAL;
dev_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
se_idx = nla_get_u32(info->attrs[NFC_ATTR_SE_INDEX]);
dev = nfc_get_device(dev_idx);
if (!dev)
return -ENODEV;
if (!dev->ops || !dev->ops->se_io)
return -ENOTSUPP;
apdu_len = nla_len(info->attrs[NFC_ATTR_SE_APDU]);
if (apdu_len == 0)
return -EINVAL;
apdu = nla_data(info->attrs[NFC_ATTR_SE_APDU]);
if (!apdu)
return -EINVAL;
ctx = kzalloc(sizeof(struct se_io_ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->dev_idx = dev_idx;
ctx->se_idx = se_idx;
return nfc_se_io(dev, se_idx, apdu, apdu_len, se_io_cb, ctx);
}
static int nfc_genl_vendor_cmd(struct sk_buff *skb,
struct genl_info *info)
{
struct nfc_dev *dev;
struct nfc_vendor_cmd *cmd;
u32 dev_idx, vid, subcmd;
u8 *data;
size_t data_len;
int i, err;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
!info->attrs[NFC_ATTR_VENDOR_ID] ||
!info->attrs[NFC_ATTR_VENDOR_SUBCMD])
return -EINVAL;
dev_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
vid = nla_get_u32(info->attrs[NFC_ATTR_VENDOR_ID]);
subcmd = nla_get_u32(info->attrs[NFC_ATTR_VENDOR_SUBCMD]);
dev = nfc_get_device(dev_idx);
if (!dev || !dev->vendor_cmds || !dev->n_vendor_cmds)
return -ENODEV;
if (info->attrs[NFC_ATTR_VENDOR_DATA]) {
data = nla_data(info->attrs[NFC_ATTR_VENDOR_DATA]);
data_len = nla_len(info->attrs[NFC_ATTR_VENDOR_DATA]);
if (data_len == 0)
return -EINVAL;
} else {
data = NULL;
data_len = 0;
}
for (i = 0; i < dev->n_vendor_cmds; i++) {
cmd = &dev->vendor_cmds[i];
if (cmd->vendor_id != vid || cmd->subcmd != subcmd)
continue;
dev->cur_cmd_info = info;
err = cmd->doit(dev, data, data_len);
dev->cur_cmd_info = NULL;
return err;
}
return -EOPNOTSUPP;
}
/* message building helper */
static inline void *nfc_hdr_put(struct sk_buff *skb, u32 portid, u32 seq,
int flags, u8 cmd)
{
/* since there is no private header just add the generic one */
return genlmsg_put(skb, portid, seq, &nfc_genl_family, flags, cmd);
}
static struct sk_buff *
__nfc_alloc_vendor_cmd_skb(struct nfc_dev *dev, int approxlen,
u32 portid, u32 seq,
enum nfc_attrs attr,
u32 oui, u32 subcmd, gfp_t gfp)
{
struct sk_buff *skb;
void *hdr;
skb = nlmsg_new(approxlen + 100, gfp);
if (!skb)
return NULL;
hdr = nfc_hdr_put(skb, portid, seq, 0, NFC_CMD_VENDOR);
if (!hdr) {
kfree_skb(skb);
return NULL;
}
if (nla_put_u32(skb, NFC_ATTR_DEVICE_INDEX, dev->idx))
goto nla_put_failure;
if (nla_put_u32(skb, NFC_ATTR_VENDOR_ID, oui))
goto nla_put_failure;
if (nla_put_u32(skb, NFC_ATTR_VENDOR_SUBCMD, subcmd))
goto nla_put_failure;
((void **)skb->cb)[0] = dev;
((void **)skb->cb)[1] = hdr;
return skb;
nla_put_failure:
kfree_skb(skb);
return NULL;
}
struct sk_buff *__nfc_alloc_vendor_cmd_reply_skb(struct nfc_dev *dev,
enum nfc_attrs attr,
u32 oui, u32 subcmd,
int approxlen)
{
if (WARN_ON(!dev->cur_cmd_info))
return NULL;
return __nfc_alloc_vendor_cmd_skb(dev, approxlen,
dev->cur_cmd_info->snd_portid,
dev->cur_cmd_info->snd_seq, attr,
oui, subcmd, GFP_KERNEL);
}
EXPORT_SYMBOL(__nfc_alloc_vendor_cmd_reply_skb);
int nfc_vendor_cmd_reply(struct sk_buff *skb)
{
struct nfc_dev *dev = ((void **)skb->cb)[0];
void *hdr = ((void **)skb->cb)[1];
/* clear CB data for netlink core to own from now on */
memset(skb->cb, 0, sizeof(skb->cb));
if (WARN_ON(!dev->cur_cmd_info)) {
kfree_skb(skb);
return -EINVAL;
}
genlmsg_end(skb, hdr);
return genlmsg_reply(skb, dev->cur_cmd_info);
}
EXPORT_SYMBOL(nfc_vendor_cmd_reply);
static const struct genl_ops nfc_genl_ops[] = {
{
.cmd = NFC_CMD_GET_DEVICE,
.doit = nfc_genl_get_device,
.dumpit = nfc_genl_dump_devices,
.done = nfc_genl_dump_devices_done,
},
{
.cmd = NFC_CMD_DEV_UP,
.doit = nfc_genl_dev_up,
},
{
.cmd = NFC_CMD_DEV_DOWN,
.doit = nfc_genl_dev_down,
},
{
.cmd = NFC_CMD_START_POLL,
.doit = nfc_genl_start_poll,
},
{
.cmd = NFC_CMD_STOP_POLL,
.doit = nfc_genl_stop_poll,
},
{
.cmd = NFC_CMD_DEP_LINK_UP,
.doit = nfc_genl_dep_link_up,
},
{
.cmd = NFC_CMD_DEP_LINK_DOWN,
.doit = nfc_genl_dep_link_down,
},
{
.cmd = NFC_CMD_GET_TARGET,
.dumpit = nfc_genl_dump_targets,
.done = nfc_genl_dump_targets_done,
},
{
.cmd = NFC_CMD_LLC_GET_PARAMS,
.doit = nfc_genl_llc_get_params,
},
{
.cmd = NFC_CMD_LLC_SET_PARAMS,
.doit = nfc_genl_llc_set_params,
},
{
.cmd = NFC_CMD_LLC_SDREQ,
.doit = nfc_genl_llc_sdreq,
},
{
.cmd = NFC_CMD_FW_DOWNLOAD,
.doit = nfc_genl_fw_download,
},
{
.cmd = NFC_CMD_ENABLE_SE,
.doit = nfc_genl_enable_se,
},
{
.cmd = NFC_CMD_DISABLE_SE,
.doit = nfc_genl_disable_se,
},
{
.cmd = NFC_CMD_GET_SE,
.dumpit = nfc_genl_dump_ses,
.done = nfc_genl_dump_ses_done,
},
{
.cmd = NFC_CMD_SE_IO,
.doit = nfc_genl_se_io,
},
{
.cmd = NFC_CMD_ACTIVATE_TARGET,
.doit = nfc_genl_activate_target,
},
{
.cmd = NFC_CMD_VENDOR,
.doit = nfc_genl_vendor_cmd,
},
{
.cmd = NFC_CMD_DEACTIVATE_TARGET,
.doit = nfc_genl_deactivate_target,
},
};
static struct genl_family nfc_genl_family __ro_after_init = {
.hdrsize = 0,
.name = NFC_GENL_NAME,
.version = NFC_GENL_VERSION,
.maxattr = NFC_ATTR_MAX,
.policy = nfc_genl_policy,
.module = THIS_MODULE,
.ops = nfc_genl_ops,
.n_ops = ARRAY_SIZE(nfc_genl_ops),
.mcgrps = nfc_genl_mcgrps,
.n_mcgrps = ARRAY_SIZE(nfc_genl_mcgrps),
};
struct urelease_work {
struct work_struct w;
u32 portid;
};
static void nfc_urelease_event_work(struct work_struct *work)
{
struct urelease_work *w = container_of(work, struct urelease_work, w);
struct class_dev_iter iter;
struct nfc_dev *dev;
pr_debug("portid %d\n", w->portid);
mutex_lock(&nfc_devlist_mutex);
nfc_device_iter_init(&iter);
dev = nfc_device_iter_next(&iter);
while (dev) {
mutex_lock(&dev->genl_data.genl_data_mutex);
if (dev->genl_data.poll_req_portid == w->portid) {
nfc_stop_poll(dev);
dev->genl_data.poll_req_portid = 0;
}
mutex_unlock(&dev->genl_data.genl_data_mutex);
dev = nfc_device_iter_next(&iter);
}
nfc_device_iter_exit(&iter);
mutex_unlock(&nfc_devlist_mutex);
kfree(w);
}
static int nfc_genl_rcv_nl_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct netlink_notify *n = ptr;
struct urelease_work *w;
if (event != NETLINK_URELEASE || n->protocol != NETLINK_GENERIC)
goto out;
pr_debug("NETLINK_URELEASE event from id %d\n", n->portid);
w = kmalloc(sizeof(*w), GFP_ATOMIC);
if (w) {
INIT_WORK((struct work_struct *) w, nfc_urelease_event_work);
w->portid = n->portid;
schedule_work((struct work_struct *) w);
}
out:
return NOTIFY_DONE;
}
void nfc_genl_data_init(struct nfc_genl_data *genl_data)
{
genl_data->poll_req_portid = 0;
mutex_init(&genl_data->genl_data_mutex);
}
void nfc_genl_data_exit(struct nfc_genl_data *genl_data)
{
mutex_destroy(&genl_data->genl_data_mutex);
}
static struct notifier_block nl_notifier = {
.notifier_call = nfc_genl_rcv_nl_event,
};
/**
* nfc_genl_init() - Initialize netlink interface
*
* This initialization function registers the nfc netlink family.
*/
int __init nfc_genl_init(void)
{
int rc;
rc = genl_register_family(&nfc_genl_family);
if (rc)
return rc;
netlink_register_notifier(&nl_notifier);
return 0;
}
/**
* nfc_genl_exit() - Deinitialize netlink interface
*
* This exit function unregisters the nfc netlink family.
*/
void nfc_genl_exit(void)
{
netlink_unregister_notifier(&nl_notifier);
genl_unregister_family(&nfc_genl_family);
}