Receiving a message in libmnl is a somewhat involved operation. Devlink's mnlg library has an implementation that is going to be handy for other tools as well. Extract it into a new helper.
Signed-off-by: Petr Machata <m...@pmachata.org> --- devlink/mnlg.c | 56 ++--------------------------------------- include/mnl_utils.h | 2 ++ lib/mnl_utils.c | 61 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 65 insertions(+), 54 deletions(-) diff --git a/devlink/mnlg.c b/devlink/mnlg.c index 4995b7af06a3..21b10c5a5669 100644 --- a/devlink/mnlg.c +++ b/devlink/mnlg.c @@ -28,7 +28,6 @@ struct mnlg_socket { uint32_t id; uint8_t version; unsigned int seq; - unsigned int portid; }; static struct nlmsghdr *__mnlg_msg_prepare(struct mnlg_socket *nlg, uint8_t cmd, @@ -57,61 +56,10 @@ int mnlg_socket_send(struct mnlg_socket *nlg, const struct nlmsghdr *nlh) return mnl_socket_sendto(nlg->nl, nlh, nlh->nlmsg_len); } -static int mnlg_cb_noop(const struct nlmsghdr *nlh, void *data) -{ - return MNL_CB_OK; -} - -static int mnlg_cb_error(const struct nlmsghdr *nlh, void *data) -{ - const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh); - - /* Netlink subsystems returns the errno value with different signess */ - if (err->error < 0) - errno = -err->error; - else - errno = err->error; - - if (nl_dump_ext_ack(nlh, NULL)) - return MNL_CB_ERROR; - - return err->error == 0 ? MNL_CB_STOP : MNL_CB_ERROR; -} - -static int mnlg_cb_stop(const struct nlmsghdr *nlh, void *data) -{ - int len = *(int *)NLMSG_DATA(nlh); - - if (len < 0) { - errno = -len; - nl_dump_ext_ack_done(nlh, len); - return MNL_CB_ERROR; - } - return MNL_CB_STOP; -} - -static mnl_cb_t mnlg_cb_array[NLMSG_MIN_TYPE] = { - [NLMSG_NOOP] = mnlg_cb_noop, - [NLMSG_ERROR] = mnlg_cb_error, - [NLMSG_DONE] = mnlg_cb_stop, - [NLMSG_OVERRUN] = mnlg_cb_noop, -}; - int mnlg_socket_recv_run(struct mnlg_socket *nlg, mnl_cb_t data_cb, void *data) { - int err; - - do { - err = mnl_socket_recvfrom(nlg->nl, nlg->buf, - MNL_SOCKET_BUFFER_SIZE); - if (err <= 0) - break; - err = mnl_cb_run2(nlg->buf, err, nlg->seq, nlg->portid, - data_cb, data, mnlg_cb_array, - ARRAY_SIZE(mnlg_cb_array)); - } while (err > 0); - - return err; + return mnlu_socket_recv_run(nlg->nl, nlg->seq, nlg->buf, MNL_SOCKET_BUFFER_SIZE, + data_cb, data); } struct group_info { diff --git a/include/mnl_utils.h b/include/mnl_utils.h index 86ce30f49a94..fa826ef1f8fe 100644 --- a/include/mnl_utils.h +++ b/include/mnl_utils.h @@ -5,5 +5,7 @@ struct mnl_socket *mnlu_socket_open(int bus); struct nlmsghdr *mnlu_msg_prepare(void *buf, uint32_t nlmsg_type, uint16_t flags, void *extra_header, size_t extra_header_size); +int mnlu_socket_recv_run(struct mnl_socket *nl, unsigned int seq, void *buf, size_t buf_size, + mnl_cb_t cb, void *data); #endif /* __MNL_UTILS_H__ */ diff --git a/lib/mnl_utils.c b/lib/mnl_utils.c index 61e8060ecbca..46384ff81cf1 100644 --- a/lib/mnl_utils.c +++ b/lib/mnl_utils.c @@ -3,11 +3,14 @@ * mnl_utils.c Helpers for working with libmnl. */ +#include <errno.h> #include <string.h> #include <time.h> #include <libmnl/libmnl.h> +#include "libnetlink.h" #include "mnl_utils.h" +#include "utils.h" struct mnl_socket *mnlu_socket_open(int bus) { @@ -47,3 +50,61 @@ struct nlmsghdr *mnlu_msg_prepare(void *buf, uint32_t nlmsg_type, uint16_t flags return nlh; } + +static int mnlu_cb_noop(const struct nlmsghdr *nlh, void *data) +{ + return MNL_CB_OK; +} + +static int mnlu_cb_error(const struct nlmsghdr *nlh, void *data) +{ + const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh); + + /* Netlink subsystems returns the errno value with different signess */ + if (err->error < 0) + errno = -err->error; + else + errno = err->error; + + if (nl_dump_ext_ack(nlh, NULL)) + return MNL_CB_ERROR; + + return err->error == 0 ? MNL_CB_STOP : MNL_CB_ERROR; +} + +static int mnlu_cb_stop(const struct nlmsghdr *nlh, void *data) +{ + int len = *(int *)NLMSG_DATA(nlh); + + if (len < 0) { + errno = -len; + nl_dump_ext_ack_done(nlh, len); + return MNL_CB_ERROR; + } + return MNL_CB_STOP; +} + +static mnl_cb_t mnlu_cb_array[NLMSG_MIN_TYPE] = { + [NLMSG_NOOP] = mnlu_cb_noop, + [NLMSG_ERROR] = mnlu_cb_error, + [NLMSG_DONE] = mnlu_cb_stop, + [NLMSG_OVERRUN] = mnlu_cb_noop, +}; + +int mnlu_socket_recv_run(struct mnl_socket *nl, unsigned int seq, void *buf, size_t buf_size, + mnl_cb_t cb, void *data) +{ + unsigned int portid = mnl_socket_get_portid(nl); + int err; + + do { + err = mnl_socket_recvfrom(nl, buf, buf_size); + if (err <= 0) + break; + err = mnl_cb_run2(buf, err, seq, portid, + cb, data, mnlu_cb_array, + ARRAY_SIZE(mnlu_cb_array)); + } while (err > 0); + + return err; +} -- 2.25.1