diff options
Diffstat (limited to 'tools/net/ynl/lib/ynl.c')
| -rw-r--r-- | tools/net/ynl/lib/ynl.c | 1068 |
1 files changed, 1068 insertions, 0 deletions
diff --git a/tools/net/ynl/lib/ynl.c b/tools/net/ynl/lib/ynl.c new file mode 100644 index 000000000000..2bcd781111d7 --- /dev/null +++ b/tools/net/ynl/lib/ynl.c @@ -0,0 +1,1068 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause +#include <errno.h> +#include <poll.h> +#include <string.h> +#include <stdlib.h> +#include <stdio.h> +#include <unistd.h> +#include <linux/types.h> +#include <linux/genetlink.h> +#include <sys/socket.h> + +#include "ynl.h" + +#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(*arr)) + +#define __yerr_msg(yse, _msg...) \ + ({ \ + struct ynl_error *_yse = (yse); \ + \ + if (_yse) { \ + snprintf(_yse->msg, sizeof(_yse->msg) - 1, _msg); \ + _yse->msg[sizeof(_yse->msg) - 1] = 0; \ + } \ + }) + +#define __yerr_code(yse, _code...) \ + ({ \ + struct ynl_error *_yse = (yse); \ + \ + if (_yse) { \ + _yse->code = _code; \ + } \ + }) + +#define __yerr(yse, _code, _msg...) \ + ({ \ + __yerr_msg(yse, _msg); \ + __yerr_code(yse, _code); \ + }) + +#define __perr(yse, _msg) __yerr(yse, errno, _msg) + +#define yerr_msg(_ys, _msg...) __yerr_msg(&(_ys)->err, _msg) +#define yerr(_ys, _code, _msg...) __yerr(&(_ys)->err, _code, _msg) +#define perr(_ys, _msg) __yerr(&(_ys)->err, errno, _msg) + +/* -- Netlink boiler plate */ +static bool +ynl_err_walk_is_sel(const struct ynl_policy_nest *policy, + const struct nlattr *attr) +{ + unsigned int type = ynl_attr_type(attr); + + return policy && type <= policy->max_attr && + policy->table[type].is_selector; +} + +static const struct ynl_policy_nest * +ynl_err_walk_sel_policy(const struct ynl_policy_attr *policy_attr, + const struct nlattr *selector) +{ + const struct ynl_policy_nest *policy = policy_attr->nest; + const char *sel; + unsigned int i; + + if (!policy_attr->is_submsg) + return policy; + + sel = ynl_attr_get_str(selector); + for (i = 0; i <= policy->max_attr; i++) { + if (!strcmp(sel, policy->table[i].name)) + return policy->table[i].nest; + } + + return NULL; +} + +static int +ynl_err_walk_report_one(const struct ynl_policy_nest *policy, + const struct nlattr *selector, unsigned int type, + char *str, int str_sz, int *n) +{ + if (!policy) { + if (*n < str_sz) + *n += snprintf(str, str_sz, "!policy"); + return 1; + } + + if (type > policy->max_attr) { + if (*n < str_sz) + *n += snprintf(str, str_sz, "!oob"); + return 1; + } + + if (!policy->table[type].name) { + if (*n < str_sz) + *n += snprintf(str, str_sz, "!name"); + return 1; + } + + if (*n < str_sz) { + int sz; + + sz = snprintf(str, str_sz - *n, + ".%s", policy->table[type].name); + *n += sz; + str += sz; + } + + if (policy->table[type].is_submsg) { + if (!selector) { + if (*n < str_sz) + *n += snprintf(str, str_sz, "(!selector)"); + return 1; + } + + if (ynl_attr_type(selector) != + policy->table[type].selector_type) { + if (*n < str_sz) + *n += snprintf(str, str_sz, "(!=selector)"); + return 1; + } + + if (*n < str_sz) + *n += snprintf(str, str_sz - *n, "(%s)", + ynl_attr_get_str(selector)); + } + + return 0; +} + +static int +ynl_err_walk(struct ynl_sock *ys, void *start, void *end, unsigned int off, + const struct ynl_policy_nest *policy, char *str, int str_sz, + const struct ynl_policy_nest **nest_pol) +{ + const struct ynl_policy_nest *next_pol; + const struct nlattr *selector = NULL; + unsigned int astart_off, aend_off; + const struct nlattr *attr; + unsigned int data_len; + unsigned int type; + bool found = false; + int n = 0; + + if (!policy) { + if (n < str_sz) + n += snprintf(str, str_sz, "!policy"); + return n; + } + + data_len = end - start; + + ynl_attr_for_each_payload(start, data_len, attr) { + astart_off = (char *)attr - (char *)start; + aend_off = (char *)ynl_attr_data_end(attr) - (char *)start; + + if (ynl_err_walk_is_sel(policy, attr)) + selector = attr; + + if (aend_off <= off) + continue; + + found = true; + break; + } + if (!found) + return 0; + + off -= astart_off; + + type = ynl_attr_type(attr); + + if (ynl_err_walk_report_one(policy, selector, type, str, str_sz, &n)) + return n; + + next_pol = ynl_err_walk_sel_policy(&policy->table[type], selector); + if (!next_pol) + return n; + + if (!off) { + if (nest_pol) + *nest_pol = next_pol; + return n; + } + + if (!next_pol) { + if (n < str_sz) + n += snprintf(str, str_sz, "!nest"); + return n; + } + + off -= sizeof(struct nlattr); + start = ynl_attr_data(attr); + end = start + ynl_attr_data_len(attr); + + return n + ynl_err_walk(ys, start, end, off, next_pol, + &str[n], str_sz - n, nest_pol); +} + +#define NLMSGERR_ATTR_MISS_TYPE (NLMSGERR_ATTR_POLICY + 1) +#define NLMSGERR_ATTR_MISS_NEST (NLMSGERR_ATTR_POLICY + 2) +#define NLMSGERR_ATTR_MAX (NLMSGERR_ATTR_MAX + 2) + +static int +ynl_ext_ack_check(struct ynl_sock *ys, const struct nlmsghdr *nlh, + unsigned int hlen) +{ + const struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {}; + char miss_attr[sizeof(ys->err.msg)]; + char bad_attr[sizeof(ys->err.msg)]; + const struct nlattr *attr; + const char *str = NULL; + + if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS)) { + yerr_msg(ys, "%s", strerror(ys->err.code)); + return YNL_PARSE_CB_OK; + } + + ynl_attr_for_each(attr, nlh, hlen) { + unsigned int len, type; + + len = ynl_attr_data_len(attr); + type = ynl_attr_type(attr); + + if (type > NLMSGERR_ATTR_MAX) + continue; + + tb[type] = attr; + + switch (type) { + case NLMSGERR_ATTR_OFFS: + case NLMSGERR_ATTR_MISS_TYPE: + case NLMSGERR_ATTR_MISS_NEST: + if (len != sizeof(__u32)) + return YNL_PARSE_CB_ERROR; + break; + case NLMSGERR_ATTR_MSG: + str = ynl_attr_get_str(attr); + if (str[len - 1]) + return YNL_PARSE_CB_ERROR; + break; + default: + break; + } + } + + bad_attr[0] = '\0'; + miss_attr[0] = '\0'; + + if (tb[NLMSGERR_ATTR_OFFS]) { + unsigned int n, off; + void *start, *end; + + ys->err.attr_offs = ynl_attr_get_u32(tb[NLMSGERR_ATTR_OFFS]); + + n = snprintf(bad_attr, sizeof(bad_attr), "%sbad attribute: ", + str ? " (" : ""); + + start = ynl_nlmsg_data_offset(ys->nlh, ys->req_hdr_len); + end = ynl_nlmsg_end_addr(ys->nlh); + + off = ys->err.attr_offs; + off -= sizeof(struct nlmsghdr); + off -= ys->req_hdr_len; + + n += ynl_err_walk(ys, start, end, off, ys->req_policy, + &bad_attr[n], sizeof(bad_attr) - n, NULL); + + if (n >= sizeof(bad_attr)) + n = sizeof(bad_attr) - 1; + bad_attr[n] = '\0'; + } + if (tb[NLMSGERR_ATTR_MISS_TYPE]) { + const struct ynl_policy_nest *nest_pol = NULL; + unsigned int n, off, type; + void *start, *end; + int n2; + + type = ynl_attr_get_u32(tb[NLMSGERR_ATTR_MISS_TYPE]); + + n = snprintf(miss_attr, sizeof(miss_attr), "%smissing attribute: ", + bad_attr[0] ? ", " : (str ? " (" : "")); + + start = ynl_nlmsg_data_offset(ys->nlh, ys->req_hdr_len); + end = ynl_nlmsg_end_addr(ys->nlh); + + nest_pol = ys->req_policy; + if (tb[NLMSGERR_ATTR_MISS_NEST]) { + off = ynl_attr_get_u32(tb[NLMSGERR_ATTR_MISS_NEST]); + off -= sizeof(struct nlmsghdr); + off -= ys->req_hdr_len; + + n += ynl_err_walk(ys, start, end, off, ys->req_policy, + &miss_attr[n], sizeof(miss_attr) - n, + &nest_pol); + } + + n2 = 0; + ynl_err_walk_report_one(nest_pol, NULL, type, &miss_attr[n], + sizeof(miss_attr) - n, &n2); + n += n2; + + if (n >= sizeof(miss_attr)) + n = sizeof(miss_attr) - 1; + miss_attr[n] = '\0'; + } + + /* Implicitly depend on ys->err.code already set */ + if (str) + yerr_msg(ys, "Kernel %s: '%s'%s%s%s", + ys->err.code ? "error" : "warning", + str, bad_attr, miss_attr, + bad_attr[0] || miss_attr[0] ? ")" : ""); + else if (bad_attr[0] || miss_attr[0]) + yerr_msg(ys, "Kernel %s: %s%s", + ys->err.code ? "error" : "warning", + bad_attr, miss_attr); + else + yerr_msg(ys, "%s", strerror(ys->err.code)); + + return YNL_PARSE_CB_OK; +} + +static int +ynl_cb_error(const struct nlmsghdr *nlh, struct ynl_parse_arg *yarg) +{ + const struct nlmsgerr *err = ynl_nlmsg_data(nlh); + unsigned int hlen; + int code; + + code = err->error >= 0 ? err->error : -err->error; + yarg->ys->err.code = code; + errno = code; + + hlen = sizeof(*err); + if (!(nlh->nlmsg_flags & NLM_F_CAPPED)) + hlen += ynl_nlmsg_data_len(&err->msg); + + ynl_ext_ack_check(yarg->ys, nlh, hlen); + + return code ? YNL_PARSE_CB_ERROR : YNL_PARSE_CB_STOP; +} + +static int ynl_cb_done(const struct nlmsghdr *nlh, struct ynl_parse_arg *yarg) +{ + int err; + + err = *(int *)NLMSG_DATA(nlh); + if (err < 0) { + yarg->ys->err.code = -err; + errno = -err; + + ynl_ext_ack_check(yarg->ys, nlh, sizeof(int)); + + return YNL_PARSE_CB_ERROR; + } + return YNL_PARSE_CB_STOP; +} + +/* Attribute validation */ + +int __ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr, + unsigned int type) +{ + const struct ynl_policy_attr *policy; + unsigned char *data; + unsigned int len; + + data = ynl_attr_data(attr); + len = ynl_attr_data_len(attr); + if (type > yarg->rsp_policy->max_attr) { + yerr(yarg->ys, YNL_ERROR_INTERNAL, + "Internal error, validating unknown attribute"); + return -1; + } + + policy = &yarg->rsp_policy->table[type]; + + switch (policy->type) { + case YNL_PT_REJECT: + yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, + "Rejected attribute (%s)", policy->name); + return -1; + case YNL_PT_IGNORE: + break; + case YNL_PT_U8: + if (len == sizeof(__u8)) + break; + yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, + "Invalid attribute (u8 %s)", policy->name); + return -1; + case YNL_PT_U16: + if (len == sizeof(__u16)) + break; + yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, + "Invalid attribute (u16 %s)", policy->name); + return -1; + case YNL_PT_U32: + if (len == sizeof(__u32)) + break; + yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, + "Invalid attribute (u32 %s)", policy->name); + return -1; + case YNL_PT_U64: + if (len == sizeof(__u64)) + break; + yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, + "Invalid attribute (u64 %s)", policy->name); + return -1; + case YNL_PT_UINT: + if (len == sizeof(__u32) || len == sizeof(__u64)) + break; + yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, + "Invalid attribute (uint %s)", policy->name); + return -1; + case YNL_PT_FLAG: + /* Let flags grow into real attrs, why not.. */ + break; + case YNL_PT_NEST: + if (!len || len >= sizeof(*attr)) + break; + yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, + "Invalid attribute (nest %s)", policy->name); + return -1; + case YNL_PT_BINARY: + if (!policy->len || len == policy->len) + break; + yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, + "Invalid attribute (binary %s)", policy->name); + return -1; + case YNL_PT_NUL_STR: + if (len && (!policy->len || len <= policy->len) && !data[len - 1]) + break; + yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, + "Invalid attribute (string %s)", policy->name); + return -1; + case YNL_PT_BITFIELD32: + if (len == sizeof(struct nla_bitfield32)) + break; + yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, + "Invalid attribute (bitfield32 %s)", policy->name); + return -1; + default: + yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, + "Invalid attribute (unknown %s)", policy->name); + return -1; + } + + return 0; +} + +int ynl_submsg_failed(struct ynl_parse_arg *yarg, const char *field_name, + const char *sel_name) +{ + yerr(yarg->ys, YNL_ERROR_SUBMSG_KEY, + "Parsing error: Sub-message key not set (msg %s, key %s)", + field_name, sel_name); + return YNL_PARSE_CB_ERROR; +} + +/* Generic code */ + +static void ynl_err_reset(struct ynl_sock *ys) +{ + ys->err.code = 0; + ys->err.attr_offs = 0; + ys->err.msg[0] = 0; +} + +struct nlmsghdr *ynl_msg_start(struct ynl_sock *ys, __u32 id, __u16 flags) +{ + struct nlmsghdr *nlh; + + ynl_err_reset(ys); + + nlh = ys->nlh = ynl_nlmsg_put_header(ys->tx_buf); + nlh->nlmsg_type = id; + nlh->nlmsg_flags = flags; + nlh->nlmsg_seq = ++ys->seq; + + /* This is a local YNL hack for length checking, we put the buffer + * length in nlmsg_pid, since messages sent to the kernel always use + * PID 0. Message needs to be terminated with ynl_msg_end(). + */ + nlh->nlmsg_pid = YNL_SOCKET_BUFFER_SIZE; + + return nlh; +} + +static int ynl_msg_end(struct ynl_sock *ys, struct nlmsghdr *nlh) +{ + /* We stash buffer length in nlmsg_pid. */ + if (nlh->nlmsg_pid == 0) { + yerr(ys, YNL_ERROR_INPUT_INVALID, + "Unknown input buffer length"); + return -EINVAL; + } + if (nlh->nlmsg_pid == YNL_MSG_OVERFLOW) { + yerr(ys, YNL_ERROR_INPUT_TOO_BIG, + "Constructed message longer than internal buffer"); + return -EMSGSIZE; + } + + nlh->nlmsg_pid = 0; + return 0; +} + +struct nlmsghdr * +ynl_gemsg_start(struct ynl_sock *ys, __u32 id, __u16 flags, + __u8 cmd, __u8 version) +{ + struct genlmsghdr gehdr; + struct nlmsghdr *nlh; + void *data; + + nlh = ynl_msg_start(ys, id, flags); + + memset(&gehdr, 0, sizeof(gehdr)); + gehdr.cmd = cmd; + gehdr.version = version; + + data = ynl_nlmsg_put_extra_header(nlh, sizeof(gehdr)); + memcpy(data, &gehdr, sizeof(gehdr)); + + return nlh; +} + +struct nlmsghdr *ynl_msg_start_req(struct ynl_sock *ys, __u32 id, __u16 flags) +{ + return ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | flags); +} + +struct nlmsghdr *ynl_msg_start_dump(struct ynl_sock *ys, __u32 id) +{ + return ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP); +} + +struct nlmsghdr * +ynl_gemsg_start_req(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version) +{ + return ynl_gemsg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK, cmd, version); +} + +struct nlmsghdr * +ynl_gemsg_start_dump(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version) +{ + return ynl_gemsg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP, + cmd, version); +} + +static int ynl_cb_null(const struct nlmsghdr *nlh, struct ynl_parse_arg *yarg) +{ + yerr(yarg->ys, YNL_ERROR_UNEXPECT_MSG, + "Received a message when none were expected"); + + return YNL_PARSE_CB_ERROR; +} + +static int +__ynl_sock_read_msgs(struct ynl_parse_arg *yarg, ynl_parse_cb_t cb, int flags) +{ + struct ynl_sock *ys = yarg->ys; + const struct nlmsghdr *nlh; + ssize_t len, rem; + int ret; + + len = recv(ys->socket, ys->rx_buf, YNL_SOCKET_BUFFER_SIZE, flags); + if (len < 0) { + if (flags & MSG_DONTWAIT && errno == EAGAIN) + return YNL_PARSE_CB_STOP; + return len; + } + + ret = YNL_PARSE_CB_STOP; + for (rem = len; rem > 0; NLMSG_NEXT(nlh, rem)) { + nlh = (struct nlmsghdr *)&ys->rx_buf[len - rem]; + if (!NLMSG_OK(nlh, rem)) { + yerr(yarg->ys, YNL_ERROR_INV_RESP, + "Invalid message or trailing data in the response."); + return YNL_PARSE_CB_ERROR; + } + + if (nlh->nlmsg_flags & NLM_F_DUMP_INTR) { + /* TODO: handle this better */ + yerr(yarg->ys, YNL_ERROR_DUMP_INTER, + "Dump interrupted / inconsistent, please retry."); + return YNL_PARSE_CB_ERROR; + } + + switch (nlh->nlmsg_type) { + case 0: + yerr(yarg->ys, YNL_ERROR_INV_RESP, + "Invalid message type in the response."); + return YNL_PARSE_CB_ERROR; + case NLMSG_NOOP: + case NLMSG_OVERRUN ... NLMSG_MIN_TYPE - 1: + ret = YNL_PARSE_CB_OK; + break; + case NLMSG_ERROR: + ret = ynl_cb_error(nlh, yarg); + break; + case NLMSG_DONE: + ret = ynl_cb_done(nlh, yarg); + break; + default: + ret = cb(nlh, yarg); + break; + } + } + + return ret; +} + +static int ynl_sock_read_msgs(struct ynl_parse_arg *yarg, ynl_parse_cb_t cb) +{ + return __ynl_sock_read_msgs(yarg, cb, 0); +} + +static int ynl_recv_ack(struct ynl_sock *ys, int ret) +{ + struct ynl_parse_arg yarg = { .ys = ys, }; + + if (!ret) { + yerr(ys, YNL_ERROR_EXPECT_ACK, + "Expecting an ACK but nothing received"); + return -1; + } + + return ynl_sock_read_msgs(&yarg, ynl_cb_null); +} + +/* Init/fini and genetlink boiler plate */ +static int +ynl_get_family_info_mcast(struct ynl_sock *ys, const struct nlattr *mcasts) +{ + const struct nlattr *entry, *attr; + unsigned int i; + + ynl_attr_for_each_nested(attr, mcasts) + ys->n_mcast_groups++; + + if (!ys->n_mcast_groups) + return 0; + + ys->mcast_groups = calloc(ys->n_mcast_groups, + sizeof(*ys->mcast_groups)); + if (!ys->mcast_groups) + return YNL_PARSE_CB_ERROR; + + i = 0; + ynl_attr_for_each_nested(entry, mcasts) { + ynl_attr_for_each_nested(attr, entry) { + if (ynl_attr_type(attr) == CTRL_ATTR_MCAST_GRP_ID) + ys->mcast_groups[i].id = ynl_attr_get_u32(attr); + if (ynl_attr_type(attr) == CTRL_ATTR_MCAST_GRP_NAME) { + strncpy(ys->mcast_groups[i].name, + ynl_attr_get_str(attr), + GENL_NAMSIZ - 1); + ys->mcast_groups[i].name[GENL_NAMSIZ - 1] = 0; + } + } + i++; + } + + return 0; +} + +static int +ynl_get_family_info_cb(const struct nlmsghdr *nlh, struct ynl_parse_arg *yarg) +{ + struct ynl_sock *ys = yarg->ys; + const struct nlattr *attr; + bool found_id = true; + + ynl_attr_for_each(attr, nlh, sizeof(struct genlmsghdr)) { + if (ynl_attr_type(attr) == CTRL_ATTR_MCAST_GROUPS) + if (ynl_get_family_info_mcast(ys, attr)) + return YNL_PARSE_CB_ERROR; + + if (ynl_attr_type(attr) != CTRL_ATTR_FAMILY_ID) + continue; + + if (ynl_attr_data_len(attr) != sizeof(__u16)) { + yerr(ys, YNL_ERROR_ATTR_INVALID, "Invalid family ID"); + return YNL_PARSE_CB_ERROR; + } + + ys->family_id = ynl_attr_get_u16(attr); + found_id = true; + } + + if (!found_id) { + yerr(ys, YNL_ERROR_ATTR_MISSING, "Family ID missing"); + return YNL_PARSE_CB_ERROR; + } + return YNL_PARSE_CB_OK; +} + +static int ynl_sock_read_family(struct ynl_sock *ys, const char *family_name) +{ + struct ynl_parse_arg yarg = { .ys = ys, }; + struct nlmsghdr *nlh; + int err; + + nlh = ynl_gemsg_start_req(ys, GENL_ID_CTRL, CTRL_CMD_GETFAMILY, 1); + ynl_attr_put_str(nlh, CTRL_ATTR_FAMILY_NAME, family_name); + + err = ynl_msg_end(ys, nlh); + if (err < 0) + return err; + + err = send(ys->socket, nlh, nlh->nlmsg_len, 0); + if (err < 0) { + perr(ys, "failed to request socket family info"); + return err; + } + + err = ynl_sock_read_msgs(&yarg, ynl_get_family_info_cb); + if (err < 0) { + free(ys->mcast_groups); + perr(ys, "failed to receive the socket family info - no such family?"); + return err; + } + + err = ynl_recv_ack(ys, err); + if (err < 0) { + free(ys->mcast_groups); + return err; + } + + return 0; +} + +struct ynl_sock * +ynl_sock_create(const struct ynl_family *yf, struct ynl_error *yse) +{ + struct sockaddr_nl addr; + struct ynl_sock *ys; + socklen_t addrlen; + int sock_type; + int one = 1; + + ys = malloc(sizeof(*ys) + 2 * YNL_SOCKET_BUFFER_SIZE); + if (!ys) + return NULL; + memset(ys, 0, sizeof(*ys)); + + ys->family = yf; + ys->tx_buf = &ys->raw_buf[0]; + ys->rx_buf = &ys->raw_buf[YNL_SOCKET_BUFFER_SIZE]; + ys->ntf_last_next = &ys->ntf_first; + + sock_type = yf->is_classic ? yf->classic_id : NETLINK_GENERIC; + + ys->socket = socket(AF_NETLINK, SOCK_RAW, sock_type); + if (ys->socket < 0) { + __perr(yse, "failed to create a netlink socket"); + goto err_free_sock; + } + + if (setsockopt(ys->socket, SOL_NETLINK, NETLINK_CAP_ACK, + &one, sizeof(one))) { + __perr(yse, "failed to enable netlink ACK"); + goto err_close_sock; + } + if (setsockopt(ys->socket, SOL_NETLINK, NETLINK_EXT_ACK, + &one, sizeof(one))) { + __perr(yse, "failed to enable netlink ext ACK"); + goto err_close_sock; + } + + memset(&addr, 0, sizeof(addr)); + addr.nl_family = AF_NETLINK; + if (bind(ys->socket, (struct sockaddr *)&addr, sizeof(addr)) < 0) { + __perr(yse, "unable to bind to a socket address"); + goto err_close_sock; + } + + memset(&addr, 0, sizeof(addr)); + addrlen = sizeof(addr); + if (getsockname(ys->socket, (struct sockaddr *)&addr, &addrlen) < 0) { + __perr(yse, "unable to read socket address"); + goto err_close_sock; + } + ys->portid = addr.nl_pid; + ys->seq = random(); + + if (yf->is_classic) { + ys->family_id = yf->classic_id; + } else if (ynl_sock_read_family(ys, yf->name)) { + if (yse) + memcpy(yse, &ys->err, sizeof(*yse)); + goto err_close_sock; + } + + return ys; + +err_close_sock: + close(ys->socket); +err_free_sock: + free(ys); + return NULL; +} + +void ynl_sock_destroy(struct ynl_sock *ys) +{ + struct ynl_ntf_base_type *ntf; + + close(ys->socket); + while ((ntf = ynl_ntf_dequeue(ys))) + ynl_ntf_free(ntf); + free(ys->mcast_groups); + free(ys); +} + +/* YNL multicast handling */ + +void ynl_ntf_free(struct ynl_ntf_base_type *ntf) +{ + ntf->free(ntf); +} + +int ynl_subscribe(struct ynl_sock *ys, const char *grp_name) +{ + unsigned int i; + int err; + + for (i = 0; i < ys->n_mcast_groups; i++) + if (!strcmp(ys->mcast_groups[i].name, grp_name)) + break; + if (i == ys->n_mcast_groups) { + yerr(ys, ENOENT, "Multicast group '%s' not found", grp_name); + return -1; + } + + err = setsockopt(ys->socket, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, + &ys->mcast_groups[i].id, + sizeof(ys->mcast_groups[i].id)); + if (err < 0) { + perr(ys, "Subscribing to multicast group failed"); + return -1; + } + + return 0; +} + +int ynl_socket_get_fd(struct ynl_sock *ys) +{ + return ys->socket; +} + +struct ynl_ntf_base_type *ynl_ntf_dequeue(struct ynl_sock *ys) +{ + struct ynl_ntf_base_type *ntf; + + if (!ynl_has_ntf(ys)) + return NULL; + + ntf = ys->ntf_first; + ys->ntf_first = ntf->next; + if (ys->ntf_last_next == &ntf->next) + ys->ntf_last_next = &ys->ntf_first; + + return ntf; +} + +static int ynl_ntf_parse(struct ynl_sock *ys, const struct nlmsghdr *nlh) +{ + struct ynl_parse_arg yarg = { .ys = ys, }; + const struct ynl_ntf_info *info; + struct ynl_ntf_base_type *rsp; + __u32 cmd; + int ret; + + if (ys->family->is_classic) { + cmd = nlh->nlmsg_type; + } else { + struct genlmsghdr *gehdr; + + gehdr = ynl_nlmsg_data(nlh); + cmd = gehdr->cmd; + } + + if (cmd >= ys->family->ntf_info_size) + return YNL_PARSE_CB_ERROR; + info = &ys->family->ntf_info[cmd]; + if (!info->cb) + return YNL_PARSE_CB_ERROR; + + rsp = calloc(1, info->alloc_sz); + rsp->free = info->free; + yarg.data = rsp->data; + yarg.rsp_policy = info->policy; + + ret = info->cb(nlh, &yarg); + if (ret <= YNL_PARSE_CB_STOP) + goto err_free; + + rsp->family = nlh->nlmsg_type; + rsp->cmd = cmd; + + *ys->ntf_last_next = rsp; + ys->ntf_last_next = &rsp->next; + + return YNL_PARSE_CB_OK; + +err_free: + info->free(rsp); + return YNL_PARSE_CB_ERROR; +} + +static int +ynl_ntf_trampoline(const struct nlmsghdr *nlh, struct ynl_parse_arg *yarg) +{ + return ynl_ntf_parse(yarg->ys, nlh); +} + +int ynl_ntf_check(struct ynl_sock *ys) +{ + struct ynl_parse_arg yarg = { .ys = ys, }; + int err; + + do { + err = __ynl_sock_read_msgs(&yarg, ynl_ntf_trampoline, + MSG_DONTWAIT); + if (err < 0) + return err; + } while (err > 0); + + return 0; +} + +/* YNL specific helpers used by the auto-generated code */ + +struct ynl_dump_list_type *YNL_LIST_END = (void *)(0xb4d123); + +void ynl_error_unknown_notification(struct ynl_sock *ys, __u8 cmd) +{ + yerr(ys, YNL_ERROR_UNKNOWN_NTF, + "Unknown notification message type '%d'", cmd); +} + +int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg) +{ + yerr(yarg->ys, YNL_ERROR_INV_RESP, "Error parsing response: %s", msg); + return YNL_PARSE_CB_ERROR; +} + +static int +ynl_check_alien(struct ynl_sock *ys, const struct nlmsghdr *nlh, __u32 rsp_cmd) +{ + if (ys->family->is_classic) { + if (nlh->nlmsg_type != rsp_cmd) + return ynl_ntf_parse(ys, nlh); + } else { + struct genlmsghdr *gehdr; + + if (ynl_nlmsg_data_len(nlh) < sizeof(*gehdr)) { + yerr(ys, YNL_ERROR_INV_RESP, + "Kernel responded with truncated message"); + return -1; + } + + gehdr = ynl_nlmsg_data(nlh); + if (gehdr->cmd != rsp_cmd) + return ynl_ntf_parse(ys, nlh); + } + + return 0; +} + +static +int ynl_req_trampoline(const struct nlmsghdr *nlh, struct ynl_parse_arg *yarg) +{ + struct ynl_req_state *yrs = (void *)yarg; + int ret; + + ret = ynl_check_alien(yrs->yarg.ys, nlh, yrs->rsp_cmd); + if (ret) + return ret < 0 ? YNL_PARSE_CB_ERROR : YNL_PARSE_CB_OK; + + return yrs->cb(nlh, &yrs->yarg); +} + +int ynl_exec(struct ynl_sock *ys, struct nlmsghdr *req_nlh, + struct ynl_req_state *yrs) +{ + int err; + + err = ynl_msg_end(ys, req_nlh); + if (err < 0) + return err; + + err = send(ys->socket, req_nlh, req_nlh->nlmsg_len, 0); + if (err < 0) + return err; + + do { + err = ynl_sock_read_msgs(&yrs->yarg, ynl_req_trampoline); + } while (err > 0); + + return err; +} + +static int +ynl_dump_trampoline(const struct nlmsghdr *nlh, struct ynl_parse_arg *data) +{ + struct ynl_dump_state *ds = (void *)data; + struct ynl_dump_list_type *obj; + struct ynl_parse_arg yarg = {}; + int ret; + + ret = ynl_check_alien(ds->yarg.ys, nlh, ds->rsp_cmd); + if (ret) + return ret < 0 ? YNL_PARSE_CB_ERROR : YNL_PARSE_CB_OK; + + obj = calloc(1, ds->alloc_sz); + if (!obj) + return YNL_PARSE_CB_ERROR; + + if (!ds->first) + ds->first = obj; + if (ds->last) + ds->last->next = obj; + ds->last = obj; + + yarg = ds->yarg; + yarg.data = &obj->data; + + return ds->cb(nlh, &yarg); +} + +static void *ynl_dump_end(struct ynl_dump_state *ds) +{ + if (!ds->first) + return YNL_LIST_END; + + ds->last->next = YNL_LIST_END; + return ds->first; +} + +int ynl_exec_dump(struct ynl_sock *ys, struct nlmsghdr *req_nlh, + struct ynl_dump_state *yds) +{ + int err; + + err = ynl_msg_end(ys, req_nlh); + if (err < 0) + return err; + + err = send(ys->socket, req_nlh, req_nlh->nlmsg_len, 0); + if (err < 0) + return err; + + do { + err = ynl_sock_read_msgs(&yds->yarg, ynl_dump_trampoline); + if (err < 0) + goto err_close_list; + } while (err > 0); + + yds->first = ynl_dump_end(yds); + return 0; + +err_close_list: + yds->first = ynl_dump_end(yds); + return -1; +} |