From 33125ac50bafd93dd98934f5f6ff23a59da8d793 Mon Sep 17 00:00:00 2001 From: Tom Gundersen Date: Thu, 21 Nov 2013 20:44:29 +0100 Subject: [PATCH 1/1] rtnl: add preliminary support for containers For now, we only support one container type IFLA_LINKINFO, and we still lack support for parsing the containers again. --- src/libsystemd-rtnl/rtnl-message.c | 140 +++++++++++++++++++++++++---- src/libsystemd-rtnl/test-rtnl.c | 26 ++++++ src/systemd/sd-rtnl.h | 6 ++ 3 files changed, 157 insertions(+), 15 deletions(-) diff --git a/src/libsystemd-rtnl/rtnl-message.c b/src/libsystemd-rtnl/rtnl-message.c index 26da7f2db..800bf2354 100644 --- a/src/libsystemd-rtnl/rtnl-message.c +++ b/src/libsystemd-rtnl/rtnl-message.c @@ -36,6 +36,8 @@ struct sd_rtnl_message { struct nlmsghdr *hdr; + struct rtattr *current_container; + struct rtattr *next_rta; size_t remaining_size; @@ -131,7 +133,7 @@ int sd_rtnl_message_link_new(uint16_t nlmsg_type, int index, unsigned int type, assert_return(nlmsg_type == RTM_NEWLINK || nlmsg_type == RTM_DELLINK || nlmsg_type == RTM_SETLINK || nlmsg_type == RTM_GETLINK, -EINVAL); - assert_return(index > 0, -EINVAL); + assert_return(nlmsg_type == RTM_NEWLINK || index > 0, -EINVAL); assert_return(ret, -EINVAL); r = message_new(ret, NLMSG_SPACE(sizeof(struct ifinfomsg))); @@ -140,6 +142,8 @@ int sd_rtnl_message_link_new(uint16_t nlmsg_type, int index, unsigned int type, (*ret)->hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)); (*ret)->hdr->nlmsg_type = nlmsg_type; + if (nlmsg_type == RTM_NEWLINK) + (*ret)->hdr->nlmsg_flags |= NLM_F_CREATE; ifi = NLMSG_DATA((*ret)->hdr); @@ -203,6 +207,21 @@ int sd_rtnl_message_get_type(sd_rtnl_message *m, uint16_t *type) { return 0; } +int sd_rtnl_message_link_get_ifindex(sd_rtnl_message *m, int *ifindex) { + struct ifinfomsg *ifi; + + assert_return(m, -EINVAL); + assert_return(ifindex, -EINVAL); + assert_return(m->hdr->nlmsg_type == RTM_NEWLINK || m->hdr->nlmsg_type == RTM_DELLINK || + m->hdr->nlmsg_type == RTM_GETLINK || m->hdr->nlmsg_type == RTM_SETLINK, -EINVAL); + + ifi = NLMSG_DATA(m->hdr); + + *ifindex = ifi->ifi_index; + + return 0; +} + /* If successful the updated message will be correctly aligned, if unsuccessful the old message is untouched */ static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data, size_t data_length) { @@ -211,11 +230,10 @@ static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data, struct rtattr *rta; char *padding; - assert_return(m, -EINVAL); - assert_return(m->hdr, -EINVAL); - assert_return(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len, -EINVAL); - assert_return(data, -EINVAL); - assert_return(data_length > 0, -EINVAL); + assert(m); + assert(m->hdr); + assert(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len); + assert(!data || data_length > 0); /* get the size of the new rta attribute (with padding at the end) */ rta_length = RTA_LENGTH(data_length); @@ -234,15 +252,28 @@ static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data, /* update message size */ m->hdr->nlmsg_len = message_length; + /* we are inside a container, extend it */ + if (m->current_container) + m->current_container->rta_len = (unsigned char *) m->hdr + + m->hdr->nlmsg_len - + (unsigned char *) m->current_container; + /* fill in the attribute */ rta->rta_type = type; rta->rta_len = rta_length; - /* we don't deal with the case where the user lies about the type and gives us - * too little data (so don't do that) - */ - padding = mempcpy(RTA_DATA(rta), data, data_length); - /* make sure also the padding at the end of the message is initialized */ - memset(padding, '\0', (unsigned char *) m->hdr + m->hdr->nlmsg_len - (unsigned char *) padding); + if (!data) { + /* this is a container, set pointer */ + m->current_container = rta; + } else { + /* we don't deal with the case where the user lies about the type + * and gives us too little data (so don't do that) + */ + padding = mempcpy(RTA_DATA(rta), data, data_length); + /* make sure also the padding at the end of the message is initialized */ + memset(padding, '\0', (unsigned char *) m->hdr + + m->hdr->nlmsg_len - + (unsigned char *) padding); + } return 0; } @@ -257,6 +288,28 @@ int sd_rtnl_message_append(sd_rtnl_message *m, unsigned short type, const void * sd_rtnl_message_get_type(m, &rtm_type); + if (m->current_container) { + switch (rtm_type) { + case RTM_NEWLINK: + case RTM_SETLINK: + case RTM_GETLINK: + case RTM_DELLINK: + switch (m->current_container->rta_type) { + case IFLA_LINKINFO: + switch (type) { + case IFLA_INFO_KIND: + return add_rtattr(m, type, data, strlen(data) + 1); + default: + return -ENOTSUP; + } + default: + return -ENOTSUP; + } + default: + return -ENOTSUP; + } + } + switch (rtm_type) { case RTM_NEWLINK: case RTM_SETLINK: @@ -329,13 +382,67 @@ int sd_rtnl_message_append(sd_rtnl_message *m, unsigned short type, const void * } } -static int message_read(sd_rtnl_message *m, unsigned short *type, void **data) { +int sd_rtnl_message_open_container(sd_rtnl_message *m, unsigned short type) { + uint16_t rtm_type; + assert_return(m, -EINVAL); - assert_return(data, -EINVAL); + assert_return(!m->current_container, -EINVAL); + + sd_rtnl_message_get_type(m, &rtm_type); + + switch (rtm_type) { + case RTM_NEWLINK: + case RTM_SETLINK: + case RTM_GETLINK: + case RTM_DELLINK: + if (type == IFLA_LINKINFO) + return add_rtattr(m, type, NULL, 0); + else + return -ENOTSUP; + default: + return -ENOTSUP; + } + + return 0; +} + +int sd_rtnl_message_close_container(sd_rtnl_message *m) { + assert_return(m, -EINVAL); + assert_return(m->current_container, -EINVAL); + + m->current_container = NULL; + + return 0; +} + +static int message_read(sd_rtnl_message *m, unsigned short *type, void **data) { + uint16_t rtm_type; + int r; + + assert(m); + assert(m->next_rta); + assert(type); + assert(data); if (!RTA_OK(m->next_rta, m->remaining_size)) return 0; + /* make sure we don't try to read a container + * TODO: add support for entering containers for reading */ + r = sd_rtnl_message_get_type(m, &rtm_type); + if (r < 0) + return r; + + switch (rtm_type) { + case RTM_NEWLINK: + case RTM_GETLINK: + case RTM_SETLINK: + case RTM_DELLINK: + if (m->next_rta->rta_type == IFLA_LINKINFO) { + return -EINVAL; + } + } + *data = RTA_DATA(m->next_rta); *type = m->next_rta->rta_type; @@ -346,11 +453,14 @@ static int message_read(sd_rtnl_message *m, unsigned short *type, void **data) { int sd_rtnl_message_read(sd_rtnl_message *m, unsigned short *type, void **data) { uint16_t rtm_type; + int r; assert_return(m, -EINVAL); assert_return(data, -EINVAL); - sd_rtnl_message_get_type(m, &rtm_type); + r = sd_rtnl_message_get_type(m, &rtm_type); + if (r < 0) + return r; switch (rtm_type) { case RTM_NEWLINK: diff --git a/src/libsystemd-rtnl/test-rtnl.c b/src/libsystemd-rtnl/test-rtnl.c index 75a210d3f..4b62c0236 100644 --- a/src/libsystemd-rtnl/test-rtnl.c +++ b/src/libsystemd-rtnl/test-rtnl.c @@ -206,6 +206,30 @@ static void test_pipe(int ifindex) { } } +static void test_container(void) { + _cleanup_sd_rtnl_message_unref_ sd_rtnl_message *m = NULL; + uint16_t type; + void *data; + + assert(sd_rtnl_message_link_new(RTM_NEWLINK, 0, 0, 0, &m) >= 0); + + assert(sd_rtnl_message_open_container(m, IFLA_LINKINFO) >= 0); + assert(sd_rtnl_message_open_container(m, IFLA_LINKINFO) == -EINVAL); + assert(sd_rtnl_message_append(m, IFLA_INFO_KIND, "kind") >= 0); + assert(sd_rtnl_message_close_container(m) >= 0); + assert(sd_rtnl_message_close_container(m) == -EINVAL); + + assert(sd_rtnl_message_read(m, &type, &data) == -EINVAL); + +/* TODO: add support for entering containers + assert(sd_rtnl_message_read(m, &type, &data) > 0); + assert(type == IFLA_INFO_KIND); + assert(streq("kind", (char *) data)); + + assert(sd_rtnl_message_read(m, &type, &data) == 0); +*/ +} + int main(void) { sd_rtnl *rtnl; sd_rtnl_message *m; @@ -220,6 +244,8 @@ int main(void) { test_route(); + test_container(); + assert(sd_rtnl_open(0, &rtnl) >= 0); assert(rtnl); diff --git a/src/systemd/sd-rtnl.h b/src/systemd/sd-rtnl.h index e5fa785a9..6db5d8a24 100644 --- a/src/systemd/sd-rtnl.h +++ b/src/systemd/sd-rtnl.h @@ -76,7 +76,13 @@ sd_rtnl_message *sd_rtnl_message_unref(sd_rtnl_message *m); int sd_rtnl_message_get_errno(sd_rtnl_message *m); int sd_rtnl_message_get_type(sd_rtnl_message *m, uint16_t *type); + +int sd_rtnl_message_link_get_ifindex(sd_rtnl_message *m, int *ifindex); + int sd_rtnl_message_append(sd_rtnl_message *m, unsigned short type, const void *data); +int sd_rtnl_message_open_container(sd_rtnl_message *m, unsigned short type); +int sd_rtnl_message_close_container(sd_rtnl_message *m); + int sd_rtnl_message_read(sd_rtnl_message *m, unsigned short *type, void **data); _SD_END_DECLARATIONS; -- 2.30.2