diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 96c55fac54c31..e3b00e23e181c 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -46,6 +46,7 @@ enum libbpf_errno { LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */ LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */ LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */ + LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */ __LIBBPF_ERRNO__END, }; @@ -297,4 +298,19 @@ int bpf_perf_event_read_simple(void *mem, unsigned long size, unsigned long page_size, void **buf, size_t *buf_len, bpf_perf_event_print_t fn, void *priv); + +struct nlmsghdr; +struct nlattr; +typedef int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb); +typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, dump_nlmsg_t, + void *cookie); +int bpf_netlink_open(unsigned int *nl_pid); +int nl_get_link(int sock, unsigned int nl_pid, dump_nlmsg_t dump_link_nlmsg, + void *cookie); +int nl_get_class(int sock, unsigned int nl_pid, int ifindex, + dump_nlmsg_t dump_class_nlmsg, void *cookie); +int nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex, + dump_nlmsg_t dump_qdisc_nlmsg, void *cookie); +int nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle, + dump_nlmsg_t dump_filter_nlmsg, void *cookie); #endif diff --git a/tools/lib/bpf/libbpf_errno.c b/tools/lib/bpf/libbpf_errno.c index d9ba851bd7f9f..2464ade3b326f 100644 --- a/tools/lib/bpf/libbpf_errno.c +++ b/tools/lib/bpf/libbpf_errno.c @@ -42,6 +42,7 @@ static const char *libbpf_strerror_table[NR_ERRNO] = { [ERRCODE_OFFSET(PROGTYPE)] = "Kernel doesn't support this program type", [ERRCODE_OFFSET(WRNGPID)] = "Wrong pid in netlink message", [ERRCODE_OFFSET(INVSEQ)] = "Invalid netlink sequence", + [ERRCODE_OFFSET(NLPARSE)] = "Incorrect netlink message parsing", }; int libbpf_strerror(int err, char *buf, size_t size) diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c index ccaa991fe9d87..469e068dd0c5f 100644 --- a/tools/lib/bpf/netlink.c +++ b/tools/lib/bpf/netlink.c @@ -18,7 +18,7 @@ #define SOL_NETLINK 270 #endif -static int bpf_netlink_open(__u32 *nl_pid) +int bpf_netlink_open(__u32 *nl_pid) { struct sockaddr_nl sa; socklen_t addrlen; @@ -61,7 +61,9 @@ static int bpf_netlink_open(__u32 *nl_pid) return ret; } -static int bpf_netlink_recv(int sock, __u32 nl_pid, int seq) +static int bpf_netlink_recv(int sock, __u32 nl_pid, int seq, + __dump_nlmsg_t _fn, dump_nlmsg_t fn, + void *cookie) { struct nlmsgerr *err; struct nlmsghdr *nh; @@ -98,6 +100,11 @@ static int bpf_netlink_recv(int sock, __u32 nl_pid, int seq) default: break; } + if (_fn) { + ret = _fn(nh, fn, cookie); + if (ret) + return ret; + } } } ret = 0; @@ -157,9 +164,161 @@ int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags) ret = -errno; goto cleanup; } - ret = bpf_netlink_recv(sock, nl_pid, seq); + ret = bpf_netlink_recv(sock, nl_pid, seq, NULL, NULL, NULL); cleanup: close(sock); return ret; } + +static int __dump_link_nlmsg(struct nlmsghdr *nlh, dump_nlmsg_t dump_link_nlmsg, + void *cookie) +{ + struct nlattr *tb[IFLA_MAX + 1], *attr; + struct ifinfomsg *ifi = NLMSG_DATA(nlh); + int len; + + len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi)); + attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi))); + if (nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0) + return -LIBBPF_ERRNO__NLPARSE; + + return dump_link_nlmsg(cookie, ifi, tb); +} + +int nl_get_link(int sock, unsigned int nl_pid, dump_nlmsg_t dump_link_nlmsg, + void *cookie) +{ + struct { + struct nlmsghdr nlh; + struct ifinfomsg ifm; + } req = { + .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)), + .nlh.nlmsg_type = RTM_GETLINK, + .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, + .ifm.ifi_family = AF_PACKET, + }; + int seq = time(NULL); + + req.nlh.nlmsg_seq = seq; + if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) + return -errno; + + return bpf_netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg, + dump_link_nlmsg, cookie); +} + +static int __dump_class_nlmsg(struct nlmsghdr *nlh, + dump_nlmsg_t dump_class_nlmsg, void *cookie) +{ + struct nlattr *tb[TCA_MAX + 1], *attr; + struct tcmsg *t = NLMSG_DATA(nlh); + int len; + + len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); + attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); + if (nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) + return -LIBBPF_ERRNO__NLPARSE; + + return dump_class_nlmsg(cookie, t, tb); +} + +int nl_get_class(int sock, unsigned int nl_pid, int ifindex, + dump_nlmsg_t dump_class_nlmsg, void *cookie) +{ + struct { + struct nlmsghdr nlh; + struct tcmsg t; + } req = { + .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), + .nlh.nlmsg_type = RTM_GETTCLASS, + .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, + .t.tcm_family = AF_UNSPEC, + .t.tcm_ifindex = ifindex, + }; + int seq = time(NULL); + + req.nlh.nlmsg_seq = seq; + if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) + return -errno; + + return bpf_netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg, + dump_class_nlmsg, cookie); +} + +static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh, + dump_nlmsg_t dump_qdisc_nlmsg, void *cookie) +{ + struct nlattr *tb[TCA_MAX + 1], *attr; + struct tcmsg *t = NLMSG_DATA(nlh); + int len; + + len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); + attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); + if (nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) + return -LIBBPF_ERRNO__NLPARSE; + + return dump_qdisc_nlmsg(cookie, t, tb); +} + +int nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex, + dump_nlmsg_t dump_qdisc_nlmsg, void *cookie) +{ + struct { + struct nlmsghdr nlh; + struct tcmsg t; + } req = { + .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), + .nlh.nlmsg_type = RTM_GETQDISC, + .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, + .t.tcm_family = AF_UNSPEC, + .t.tcm_ifindex = ifindex, + }; + int seq = time(NULL); + + req.nlh.nlmsg_seq = seq; + if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) + return -errno; + + return bpf_netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg, + dump_qdisc_nlmsg, cookie); +} + +static int __dump_filter_nlmsg(struct nlmsghdr *nlh, + dump_nlmsg_t dump_filter_nlmsg, void *cookie) +{ + struct nlattr *tb[TCA_MAX + 1], *attr; + struct tcmsg *t = NLMSG_DATA(nlh); + int len; + + len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); + attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); + if (nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) + return -LIBBPF_ERRNO__NLPARSE; + + return dump_filter_nlmsg(cookie, t, tb); +} + +int nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle, + dump_nlmsg_t dump_filter_nlmsg, void *cookie) +{ + struct { + struct nlmsghdr nlh; + struct tcmsg t; + } req = { + .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), + .nlh.nlmsg_type = RTM_GETTFILTER, + .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, + .t.tcm_family = AF_UNSPEC, + .t.tcm_ifindex = ifindex, + .t.tcm_parent = handle, + }; + int seq = time(NULL); + + req.nlh.nlmsg_seq = seq; + if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) + return -errno; + + return bpf_netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg, + dump_filter_nlmsg, cookie); +} diff --git a/tools/lib/bpf/nlattr.c b/tools/lib/bpf/nlattr.c index 4719434278b20..49f514119bdb0 100644 --- a/tools/lib/bpf/nlattr.c +++ b/tools/lib/bpf/nlattr.c @@ -26,11 +26,6 @@ static uint16_t nla_attr_minlen[NLA_TYPE_MAX+1] = { [NLA_FLAG] = 0, }; -static int nla_len(const struct nlattr *nla) -{ - return nla->nla_len - NLA_HDRLEN; -} - static struct nlattr *nla_next(const struct nlattr *nla, int *remaining) { int totlen = NLA_ALIGN(nla->nla_len); @@ -46,11 +41,6 @@ static int nla_ok(const struct nlattr *nla, int remaining) nla->nla_len <= remaining; } -static void *nla_data(const struct nlattr *nla) -{ - return (char *) nla + NLA_HDRLEN; -} - static int nla_type(const struct nlattr *nla) { return nla->nla_type & NLA_TYPE_MASK; @@ -114,8 +104,8 @@ static inline int nlmsg_len(const struct nlmsghdr *nlh) * @see nla_validate * @return 0 on success or a negative error code. */ -static int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len, - struct nla_policy *policy) +int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len, + struct nla_policy *policy) { struct nlattr *nla; int rem, err; @@ -146,6 +136,25 @@ static int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int return err; } +/** + * Create attribute index based on nested attribute + * @arg tb Index array to be filled (maxtype+1 elements). + * @arg maxtype Maximum attribute type expected and accepted. + * @arg nla Nested Attribute. + * @arg policy Attribute validation policy. + * + * Feeds the stream of attributes nested into the specified attribute + * to nla_parse(). + * + * @see nla_parse + * @return 0 on success or a negative error code. + */ +int nla_parse_nested(struct nlattr *tb[], int maxtype, struct nlattr *nla, + struct nla_policy *policy) +{ + return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); +} + /* dump netlink extended ack error message */ int nla_dump_errormsg(struct nlmsghdr *nlh) { diff --git a/tools/lib/bpf/nlattr.h b/tools/lib/bpf/nlattr.h index 931a71f68f934..a6e2396bce7cc 100644 --- a/tools/lib/bpf/nlattr.h +++ b/tools/lib/bpf/nlattr.h @@ -67,6 +67,44 @@ struct nla_policy { nla_ok(pos, rem); \ pos = nla_next(pos, &(rem))) +/** + * nla_data - head of payload + * @nla: netlink attribute + */ +static inline void *nla_data(const struct nlattr *nla) +{ + return (char *) nla + NLA_HDRLEN; +} + +static inline uint8_t nla_getattr_u8(const struct nlattr *nla) +{ + return *(uint8_t *)nla_data(nla); +} + +static inline uint32_t nla_getattr_u32(const struct nlattr *nla) +{ + return *(uint32_t *)nla_data(nla); +} + +static inline const char *nla_getattr_str(const struct nlattr *nla) +{ + return (const char *)nla_data(nla); +} + +/** + * nla_len - length of payload + * @nla: netlink attribute + */ +static inline int nla_len(const struct nlattr *nla) +{ + return nla->nla_len - NLA_HDRLEN; +} + +int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len, + struct nla_policy *policy); +int nla_parse_nested(struct nlattr *tb[], int maxtype, struct nlattr *nla, + struct nla_policy *policy); + int nla_dump_errormsg(struct nlmsghdr *nlh); #endif /* __NLATTR_H */