^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * NETLINK Netlink attributes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Copyright (c) 2003-2013 Thomas Graf <tgraf@suug.ch>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <stdio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/rtnetlink.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include "nlattr.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include "libbpf_internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) static uint16_t nla_attr_minlen[LIBBPF_NLA_TYPE_MAX+1] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) [LIBBPF_NLA_U8] = sizeof(uint8_t),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) [LIBBPF_NLA_U16] = sizeof(uint16_t),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) [LIBBPF_NLA_U32] = sizeof(uint32_t),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) [LIBBPF_NLA_U64] = sizeof(uint64_t),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) [LIBBPF_NLA_STRING] = 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) [LIBBPF_NLA_FLAG] = 0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) static struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) int totlen = NLA_ALIGN(nla->nla_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) *remaining -= totlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) return (struct nlattr *) ((char *) nla + totlen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) static int nla_ok(const struct nlattr *nla, int remaining)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) return remaining >= sizeof(*nla) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) nla->nla_len >= sizeof(*nla) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) nla->nla_len <= remaining;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) static int nla_type(const struct nlattr *nla)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) return nla->nla_type & NLA_TYPE_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) static int validate_nla(struct nlattr *nla, int maxtype,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) struct libbpf_nla_policy *policy)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) struct libbpf_nla_policy *pt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) unsigned int minlen = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) int type = nla_type(nla);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) if (type < 0 || type > maxtype)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) pt = &policy[type];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) if (pt->type > LIBBPF_NLA_TYPE_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) if (pt->minlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) minlen = pt->minlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) else if (pt->type != LIBBPF_NLA_UNSPEC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) minlen = nla_attr_minlen[pt->type];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) if (libbpf_nla_len(nla) < minlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) if (pt->maxlen && libbpf_nla_len(nla) > pt->maxlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) if (pt->type == LIBBPF_NLA_STRING) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) char *data = libbpf_nla_data(nla);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) if (data[libbpf_nla_len(nla) - 1] != '\0')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) static inline int nlmsg_len(const struct nlmsghdr *nlh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) return nlh->nlmsg_len - NLMSG_HDRLEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) * Create attribute index based on a stream of attributes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * @arg tb Index array to be filled (maxtype+1 elements).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) * @arg maxtype Maximum attribute type expected and accepted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) * @arg head Head of attribute stream.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) * @arg len Length of attribute stream.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) * @arg policy Attribute validation policy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) * Iterates over the stream of attributes and stores a pointer to each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * attribute in the index array using the attribute type as index to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) * the array. Attribute with a type greater than the maximum type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * specified will be silently ignored in order to maintain backwards
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) * compatibility. If \a policy is not NULL, the attribute will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * validated using the specified policy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) * @see nla_validate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) * @return 0 on success or a negative error code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) int libbpf_nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) int len, struct libbpf_nla_policy *policy)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) struct nlattr *nla;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) int rem, err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) libbpf_nla_for_each_attr(nla, head, len, rem) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) int type = nla_type(nla);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) if (type > maxtype)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) if (policy) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) err = validate_nla(nla, maxtype, policy);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) if (err < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) goto errout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) if (tb[type])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) pr_warn("Attribute of type %#x found multiple times in message, "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) "previous attribute is being ignored.\n", type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) tb[type] = nla;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) errout:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) * Create attribute index based on nested attribute
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * @arg tb Index array to be filled (maxtype+1 elements).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) * @arg maxtype Maximum attribute type expected and accepted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) * @arg nla Nested Attribute.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) * @arg policy Attribute validation policy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) * Feeds the stream of attributes nested into the specified attribute
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) * to libbpf_nla_parse().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * @see libbpf_nla_parse
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) * @return 0 on success or a negative error code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) int libbpf_nla_parse_nested(struct nlattr *tb[], int maxtype,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) struct nlattr *nla,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) struct libbpf_nla_policy *policy)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) return libbpf_nla_parse(tb, maxtype, libbpf_nla_data(nla),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) libbpf_nla_len(nla), policy);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) /* dump netlink extended ack error message */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) int libbpf_nla_dump_errormsg(struct nlmsghdr *nlh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) struct libbpf_nla_policy extack_policy[NLMSGERR_ATTR_MAX + 1] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) [NLMSGERR_ATTR_MSG] = { .type = LIBBPF_NLA_STRING },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) [NLMSGERR_ATTR_OFFS] = { .type = LIBBPF_NLA_U32 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) struct nlattr *tb[NLMSGERR_ATTR_MAX + 1], *attr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) struct nlmsgerr *err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) char *errmsg = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) int hlen, alen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) /* no TLVs, nothing to do here */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) err = (struct nlmsgerr *)NLMSG_DATA(nlh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) hlen = sizeof(*err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) /* if NLM_F_CAPPED is set then the inner err msg was capped */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) hlen += nlmsg_len(&err->msg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) attr = (struct nlattr *) ((void *) err + hlen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) alen = nlh->nlmsg_len - hlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) if (libbpf_nla_parse(tb, NLMSGERR_ATTR_MAX, attr, alen,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) extack_policy) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) pr_warn("Failed to parse extended error attributes\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) if (tb[NLMSGERR_ATTR_MSG])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) errmsg = (char *) libbpf_nla_data(tb[NLMSGERR_ATTR_MSG]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) pr_warn("Kernel error message: %s\n", errmsg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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