git: 5f19f790b392 - main - netlink: add snl(3) support for parsing unknown-size arrays
Date: Sat, 27 May 2023 11:14:13 UTC
The branch main has been updated by melifaro:
URL: https://cgit.FreeBSD.org/src/commit/?id=5f19f790b3923354871ce049b84c7807ecb0cad5
commit 5f19f790b3923354871ce049b84c7807ecb0cad5
Author: Alexander V. Chernikov <melifaro@FreeBSD.org>
AuthorDate: 2023-05-27 11:09:01 +0000
Commit: Alexander V. Chernikov <melifaro@FreeBSD.org>
CommitDate: 2023-05-27 11:13:14 +0000
netlink: add snl(3) support for parsing unknown-size arrays
Reviewed by: bapt
Differential Review: https://reviews.freebsd.org/D40282
MFC after: 2 weeks
---
sys/netlink/netlink_snl.h | 122 ++++++++++++++++++++++++++------
sys/netlink/netlink_snl_route_parsers.h | 19 +++--
2 files changed, 116 insertions(+), 25 deletions(-)
diff --git a/sys/netlink/netlink_snl.h b/sys/netlink/netlink_snl.h
index 5844994b5e47..6d97c1afd4ee 100644
--- a/sys/netlink/netlink_snl.h
+++ b/sys/netlink/netlink_snl.h
@@ -149,33 +149,40 @@ struct snl_attr_parser {
typedef bool snl_parse_post_f(struct snl_state *ss, void *target);
struct snl_hdr_parser {
- int hdr_off; /* aligned header size */
- int fp_size;
- int np_size;
+ uint16_t in_hdr_size; /* Input header size */
+ uint16_t out_size; /* Output structure size */
+ uint16_t fp_size; /* Number of items in field parser */
+ uint16_t np_size; /* Number of items in attribute parser */
const struct snl_field_parser *fp; /* array of header field parsers */
const struct snl_attr_parser *np; /* array of attribute parsers */
snl_parse_post_f *cb_post; /* post-parse callback */
};
-#define SNL_DECLARE_PARSER_EXT(_name, _t, _fp, _np, _cb) \
-static const struct snl_hdr_parser _name = { \
- .hdr_off = sizeof(_t), \
- .fp = &((_fp)[0]), \
- .np = &((_np)[0]), \
- .fp_size = NL_ARRAY_LEN(_fp), \
- .np_size = NL_ARRAY_LEN(_np), \
- .cb_post = _cb, \
+#define SNL_DECLARE_PARSER_EXT(_name, _sz_h_in, _sz_out, _fp, _np, _cb) \
+static const struct snl_hdr_parser _name = { \
+ .in_hdr_size = _sz_h_in, \
+ .out_size = _sz_out, \
+ .fp = &((_fp)[0]), \
+ .np = &((_np)[0]), \
+ .fp_size = NL_ARRAY_LEN(_fp), \
+ .np_size = NL_ARRAY_LEN(_np), \
+ .cb_post = _cb, \
}
-#define SNL_DECLARE_PARSER(_name, _t, _fp, _np) \
- SNL_DECLARE_PARSER_EXT(_name, _t, _fp, _np, NULL)
+#define SNL_DECLARE_PARSER(_name, _t, _fp, _np) \
+ SNL_DECLARE_PARSER_EXT(_name, sizeof(_t), 0, _fp, _np, NULL)
-#define SNL_DECLARE_ATTR_PARSER(_name, _np) \
-static const struct snl_hdr_parser _name = { \
- .np = &((_np)[0]), \
- .np_size = NL_ARRAY_LEN(_np), \
+#define SNL_DECLARE_ATTR_PARSER_EXT(_name, _sz_out, _np, _cb) \
+static const struct snl_hdr_parser _name = { \
+ .out_size = _sz_out, \
+ .np = &((_np)[0]), \
+ .np_size = NL_ARRAY_LEN(_np), \
+ .cb_post = _cb, \
}
+#define SNL_DECLARE_ATTR_PARSER(_name, _np) \
+ SNL_DECLARE_ATTR_PARSER_EXT(_name, 0, _np, NULL)
+
static inline void *
snl_allocz(struct snl_state *ss, int len)
@@ -471,11 +478,13 @@ static inline bool
snl_parse_header(struct snl_state *ss, void *hdr, int len,
const struct snl_hdr_parser *parser, void *target)
{
+ struct nlattr *nla_head;
+
/* Extract fields first (if any) */
- snl_parse_fields(ss, hdr, parser->hdr_off, parser->fp, parser->fp_size, target);
+ snl_parse_fields(ss, hdr, parser->in_hdr_size, parser->fp, parser->fp_size, target);
- struct nlattr *nla_head = (struct nlattr *)(void *)((char *)hdr + parser->hdr_off);
- bool result = snl_parse_attrs_raw(ss, nla_head, len - parser->hdr_off,
+ nla_head = (struct nlattr *)(void *)((char *)hdr + parser->in_hdr_size);
+ bool result = snl_parse_attrs_raw(ss, nla_head, len - parser->in_hdr_size,
parser->np, parser->np_size, target);
if (result && parser->cb_post != NULL)
@@ -642,6 +651,78 @@ snl_attr_get_nested(struct snl_state *ss, struct nlattr *nla, const void *arg, v
return (snl_parse_header(ss, NLA_DATA(nla), NLA_DATA_LEN(nla), p, target));
}
+struct snl_parray {
+ uint32_t count;
+ void **items;
+};
+
+static inline bool
+snl_attr_get_parray_sz(struct snl_state *ss, struct nlattr *container_nla,
+ uint32_t start_size, const void *arg, void *target)
+{
+ const struct snl_hdr_parser *p = (const struct snl_hdr_parser *)arg;
+ struct snl_parray *array = target;
+ struct nlattr *nla;
+ uint32_t count = 0, size = start_size;
+
+ if (p->out_size == 0)
+ return (false);
+
+ array->items = snl_allocz(ss, size * sizeof(void *));
+ if (array->items == NULL)
+ return (false);
+
+ /*
+ * If the provided parser is an attribute parser, assume that each
+ * nla in the container nla is the container nla itself and parse
+ * the contents of this nla.
+ * Otherwise, run the parser on raw data, assuming the header of this
+ * data has u16 field with total size in the beginning.
+ */
+ uint32_t data_off = 0;
+
+ if (p->in_hdr_size == 0)
+ data_off = sizeof(struct nlattr);
+
+ NLA_FOREACH(nla, NLA_DATA(container_nla), NLA_DATA_LEN(container_nla)) {
+ void *item = snl_allocz(ss, p->out_size);
+
+ if (item == NULL)
+ return (false);
+
+ void *data = (char *)(void *)nla + data_off;
+ int data_len = nla->nla_len - data_off;
+
+ if (!(snl_parse_header(ss, data, data_len, p, item)))
+ return (false);
+
+ if (count == size) {
+ uint32_t new_size = size * 2;
+ void **new_array = snl_allocz(ss, new_size *sizeof(void *));
+
+ memcpy(new_array, array->items, size * sizeof(void *));
+ array->items = new_array;
+ size = new_size;
+ }
+ array->items[count++] = item;
+ }
+ array->count = count;
+
+ return (true);
+}
+
+/*
+ * Parses and stores the unknown-size array.
+ * Assumes each array item is a container and the NLAs in the container are parsable
+ * by the parser provided in @arg.
+ * Assumes @target is struct snl_parray
+ */
+static inline bool
+snl_attr_get_parray(struct snl_state *ss, struct nlattr *nla, const void *arg, void *target)
+{
+ return (snl_attr_get_parray_sz(ss, nla, 8, arg, target));
+}
+
static inline bool
snl_attr_get_nla(struct snl_state *ss __unused, struct nlattr *nla,
const void *arg __unused, void *target)
@@ -878,6 +959,7 @@ snl_realloc_msg_buffer(struct snl_writer *nw, size_t sz)
memcpy(new_base, nw->base, nw->offset);
if (nw->hdr != NULL) {
int hdr_off = (char *)(nw->hdr) - nw->base;
+
nw->hdr = (struct nlmsghdr *)(void *)((char *)new_base + hdr_off);
}
nw->base = new_base;
diff --git a/sys/netlink/netlink_snl_route_parsers.h b/sys/netlink/netlink_snl_route_parsers.h
index c76e1cd6440a..0ab338cbe6e8 100644
--- a/sys/netlink/netlink_snl_route_parsers.h
+++ b/sys/netlink/netlink_snl_route_parsers.h
@@ -85,7 +85,9 @@ _cb_p_mp_nh(struct snl_state *ss __unused, void *_target)
}
#undef _IN
#undef _OUT
-SNL_DECLARE_PARSER_EXT(_mpath_nh_parser, struct rtnexthop, _fp_p_mp_nh, _nla_p_mp_nh, _cb_p_mp_nh);
+SNL_DECLARE_PARSER_EXT(_mpath_nh_parser, sizeof(struct rtnexthop),
+ sizeof(struct rta_mpath_nh), _fp_p_mp_nh, _nla_p_mp_nh,
+ _cb_p_mp_nh);
struct rta_mpath {
int num_nhops;
@@ -185,7 +187,9 @@ _cb_p_route(struct snl_state *ss __unused, void *_target)
}
#undef _IN
#undef _OUT
-SNL_DECLARE_PARSER_EXT(snl_rtm_route_parser, struct rtmsg, _fp_p_route, _nla_p_route, _cb_p_route);
+SNL_DECLARE_PARSER_EXT(snl_rtm_route_parser, sizeof(struct rtmsg),
+ sizeof(struct snl_parsed_route), _fp_p_route, _nla_p_route,
+ _cb_p_route);
/* RTM_<NEW|DEL|GET>LINK message parser */
struct snl_parsed_link {
@@ -299,7 +303,9 @@ _cb_p_neigh(struct snl_state *ss __unused, void *_target)
}
#undef _IN
#undef _OUT
-SNL_DECLARE_PARSER_EXT(snl_rtm_neigh_parser, struct ndmsg, _fp_p_neigh_s, _nla_p_neigh_s, _cb_p_neigh);
+SNL_DECLARE_PARSER_EXT(snl_rtm_neigh_parser, sizeof(struct ndmsg),
+ sizeof(struct snl_parsed_neigh), _fp_p_neigh_s, _nla_p_neigh_s,
+ _cb_p_neigh);
struct snl_parsed_addr {
uint8_t ifa_family;
@@ -347,7 +353,9 @@ _cb_p_addr(struct snl_state *ss __unused, void *_target)
}
#undef _IN
#undef _OUT
-SNL_DECLARE_PARSER_EXT(snl_rtm_addr_parser, struct ifaddrmsg, _fp_p_addr_s, _nla_p_addr_s, _cb_p_addr);
+SNL_DECLARE_PARSER_EXT(snl_rtm_addr_parser, sizeof(struct ifaddrmsg),
+ sizeof(struct snl_parsed_addr), _fp_p_addr_s, _nla_p_addr_s,
+ _cb_p_addr);
struct snl_parsed_nhop {
uint32_t nha_id;
@@ -397,7 +405,8 @@ _cb_p_nh(struct snl_state *ss __unused, void *_target)
}
#undef _IN
#undef _OUT
-SNL_DECLARE_PARSER_EXT(snl_nhmsg_parser, struct nhmsg, _fp_p_nh, _nla_p_nh, _cb_p_nh);
+SNL_DECLARE_PARSER_EXT(snl_nhmsg_parser, sizeof(struct nhmsg),
+ sizeof(struct snl_parsed_nhop), _fp_p_nh, _nla_p_nh, _cb_p_nh);
static const struct snl_hdr_parser *snl_all_route_parsers[] = {
&_metrics_mp_nh_parser, &_mpath_nh_parser, &_metrics_parser, &snl_rtm_route_parser,