From e5c4350b0d91551041795eb3c4fd4f22b2604ee2 Mon Sep 17 00:00:00 2001 From: Tom Gundersen Date: Fri, 24 Jan 2014 21:04:05 +0100 Subject: [PATCH] sd-rtnl: add support for reading containers Also insist on messages being sealed before reading them. In other words we don't allow interleaving of reading and appending to messages. --- src/libsystemd/sd-rtnl/rtnl-message.c | 76 +++++++++++++++++++++------ src/libsystemd/sd-rtnl/test-rtnl.c | 37 +++++++++---- src/systemd/sd-rtnl.h | 1 + 3 files changed, 88 insertions(+), 26 deletions(-) diff --git a/src/libsystemd/sd-rtnl/rtnl-message.c b/src/libsystemd/sd-rtnl/rtnl-message.c index 3cf8579cf..85c59bfed 100644 --- a/src/libsystemd/sd-rtnl/rtnl-message.c +++ b/src/libsystemd/sd-rtnl/rtnl-message.c @@ -45,6 +45,7 @@ struct sd_rtnl_message { #define GET_CONTAINER(m, i) (i < (m)->n_containers ? (struct rtattr*)((uint8_t*)(m)->hdr + (m)->container_offsets[i]) : NULL) #define NEXT_RTA(m) ((struct rtattr*)((uint8_t*)(m)->hdr + (m)->next_rta_offset)) #define UPDATE_RTA(m, new) (m)->next_rta_offset = (uint8_t*)(new) - (uint8_t*)(m)->hdr; +#define PUSH_CONTAINER(m, new) (m)->container_offsets[(m)->n_containers ++] = (uint8_t*)(new) - (uint8_t*)(m)->hdr; static int message_new(sd_rtnl_message **ret, size_t initial_size) { sd_rtnl_message *m; @@ -378,6 +379,7 @@ static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data, assert(m); assert(m->hdr); + assert(!m->sealed); assert(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len); assert(!data || data_length > 0); assert(data || m->n_containers < RTNL_CONTAINER_DEPTH); @@ -428,6 +430,7 @@ int sd_rtnl_message_append_string(sd_rtnl_message *m, unsigned short type, const int r; assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); assert_return(data, -EINVAL); r = sd_rtnl_message_get_type(m, &rtm_type); @@ -477,6 +480,7 @@ int sd_rtnl_message_append_u16(sd_rtnl_message *m, unsigned short type, uint16_t int r; assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); r = sd_rtnl_message_get_type(m, &rtm_type); if (r < 0) @@ -512,6 +516,7 @@ int sd_rtnl_message_append_u32(sd_rtnl_message *m, unsigned short type, uint32_t int r; assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); r = sd_rtnl_message_get_type(m, &rtm_type); if (r < 0) @@ -563,6 +568,7 @@ int sd_rtnl_message_append_in_addr(sd_rtnl_message *m, unsigned short type, cons int r; assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); assert_return(data, -EINVAL); r = sd_rtnl_message_get_type(m, &rtm_type); @@ -624,6 +630,7 @@ int sd_rtnl_message_append_in6_addr(sd_rtnl_message *m, unsigned short type, con int r; assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); assert_return(data, -EINVAL); r = sd_rtnl_message_get_type(m, &rtm_type); @@ -682,6 +689,7 @@ int sd_rtnl_message_append_ether_addr(sd_rtnl_message *m, unsigned short type, c int r; assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); assert_return(data, -EINVAL); sd_rtnl_message_get_type(m, &rtm_type); @@ -714,6 +722,7 @@ int sd_rtnl_message_open_container(sd_rtnl_message *m, unsigned short type) { uint16_t rtm_type; assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); sd_rtnl_message_get_type(m, &rtm_type); @@ -732,6 +741,7 @@ int sd_rtnl_message_open_container(sd_rtnl_message *m, unsigned short type) { int sd_rtnl_message_close_container(sd_rtnl_message *m) { assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); assert_return(m->n_containers > 0, -EINVAL); m->n_containers --; @@ -744,34 +754,57 @@ int sd_rtnl_message_read(sd_rtnl_message *m, unsigned short *type, void **data) uint16_t rtm_type; int r; - assert(m); - assert(m->next_rta_offset); - assert(type); - assert(data); + assert_return(m, -EINVAL); + assert_return(m->sealed, -EPERM); + assert_return(m->next_rta_offset, -EINVAL); + assert_return(type, -EINVAL); + assert_return(data, -EINVAL); - remaining_size = m->hdr->nlmsg_len - m->next_rta_offset; + /* only read until the end of the current container */ + if (m->n_containers) + remaining_size = GET_CONTAINER(m, m->n_containers - 1)->rta_len - + (m->next_rta_offset - + m->container_offsets[m->n_containers - 1]); + else + remaining_size = m->hdr->nlmsg_len - m->next_rta_offset; if (!RTA_OK(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 */ + /* if we read a container, enter it and return its type */ r = sd_rtnl_message_get_type(m, &rtm_type); if (r < 0) return r; - if (message_type_is_link(rtm_type) && - NEXT_RTA(m)->rta_type == IFLA_LINKINFO) - return -EINVAL; - - *data = RTA_DATA(NEXT_RTA(m)); *type = NEXT_RTA(m)->rta_type; - UPDATE_RTA(m, RTA_NEXT(NEXT_RTA(m), remaining_size)); + if (message_type_is_link(rtm_type) && + ((m->n_containers == 0 && + NEXT_RTA(m)->rta_type == IFLA_LINKINFO) || + (m->n_containers == 1 && + GET_CONTAINER(m, 0)->rta_type == IFLA_LINKINFO && + NEXT_RTA(m)->rta_type == IFLA_INFO_DATA))) { + *data = NULL; + PUSH_CONTAINER(m, NEXT_RTA(m)); + UPDATE_RTA(m, RTA_DATA(NEXT_RTA(m))); + } else { + *data = RTA_DATA(NEXT_RTA(m)); + UPDATE_RTA(m, RTA_NEXT(NEXT_RTA(m), remaining_size)); + } return 1; } +int sd_rtnl_message_exit_container(sd_rtnl_message *m) { + assert_return(m, -EINVAL); + assert_return(m->sealed, -EINVAL); + assert_return(m->n_containers > 0, -EINVAL); + + m->n_containers --; + + return 0; +} + uint32_t message_get_serial(sd_rtnl_message *m) { assert(m); assert(m->hdr); @@ -794,16 +827,23 @@ int sd_rtnl_message_get_errno(sd_rtnl_message *m) { } int message_seal(sd_rtnl *nl, sd_rtnl_message *m) { - assert(nl); + int r; + assert(m); assert(m->hdr); if (m->sealed) return -EPERM; - m->hdr->nlmsg_seq = nl->serial++; + if (nl) + m->hdr->nlmsg_seq = nl->serial++; + m->sealed = true; + r = sd_rtnl_message_rewind(m); + if (r < 0) + return r; + return 0; } @@ -876,6 +916,9 @@ int socket_read_message(sd_rtnl *nl, sd_rtnl_message **ret) { if (r < 0) return r; + /* don't allow sealing/appending to received messages */ + m->sealed = true; + addr_len = sizeof(addr); k = recvfrom(nl->fd, m->hdr, need, @@ -961,6 +1004,7 @@ int sd_rtnl_message_rewind(sd_rtnl_message *m) { struct rtmsg *rtm; assert_return(m, -EINVAL); + assert_return(m->sealed, -EPERM); assert_return(m->hdr, -EINVAL); switch(m->hdr->nlmsg_type) { @@ -990,5 +1034,7 @@ int sd_rtnl_message_rewind(sd_rtnl_message *m) { return -ENOTSUP; } + m->n_containers = 0; + return 0; } diff --git a/src/libsystemd/sd-rtnl/test-rtnl.c b/src/libsystemd/sd-rtnl/test-rtnl.c index 98213d678..a173b0fc6 100644 --- a/src/libsystemd/sd-rtnl/test-rtnl.c +++ b/src/libsystemd/sd-rtnl/test-rtnl.c @@ -27,6 +27,7 @@ #include "sd-rtnl.h" #include "socket-util.h" #include "rtnl-util.h" +#include "rtnl-internal.h" #include "event-util.h" static void test_link_configure(sd_rtnl *rtnl, int ifindex) { @@ -42,6 +43,8 @@ static void test_link_configure(sd_rtnl *rtnl, int ifindex) { assert(sd_rtnl_message_append_ether_addr(message, IFLA_ADDRESS, ether_aton(mac)) >= 0); assert(sd_rtnl_message_append_u32(message, IFLA_MTU, mtu) >= 0); + assert(sd_rtnl_call(rtnl, message, 0, NULL) == 1); + assert(sd_rtnl_message_read(message, &type, &data) > 0); assert(type == IFLA_IFNAME); assert(streq(name, (char *) data)); @@ -53,8 +56,6 @@ static void test_link_configure(sd_rtnl *rtnl, int ifindex) { assert(sd_rtnl_message_read(message, &type, &data) > 0); assert(type == IFLA_MTU); assert(mtu == *(unsigned int *) data); - - assert(sd_rtnl_call(rtnl, message, 0, NULL) == 1); } static void test_route(void) { @@ -85,6 +86,8 @@ static void test_route(void) { return; } + assert(message_seal(NULL, req) >= 0); + assert(sd_rtnl_message_read(req, &type, &data) > 0); assert(type == RTA_GATEWAY); assert(((struct in_addr *)data)->s_addr == addr.s_addr); @@ -224,15 +227,26 @@ static void test_container(void) { 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); + assert(message_seal(NULL, m) >= 0); -/* TODO: add support for entering containers - assert(sd_rtnl_message_read(m, &type, &data) > 0); + assert(sd_rtnl_message_read(m, &type, &data) >= 0); + assert(type == IFLA_LINKINFO); + assert(data == NULL); + 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); -*/ + assert(streq("kind", (char *)data)); + assert(sd_rtnl_message_read(m, &type, &data) >= 0); + assert(type == IFLA_INFO_DATA); + assert(data == NULL); + assert(sd_rtnl_message_read(m, &type, &data) >= 0); + assert(type == IFLA_VLAN_ID); + assert(*(uint16_t *)data == 100); + assert(sd_rtnl_message_exit_container(m) >= 0); + assert(sd_rtnl_message_read(m, &type, &data) >= 0); + assert(type == IFLA_INFO_KIND); + assert(streq("kind", (char *)data)); + assert(sd_rtnl_message_exit_container(m) >= 0); + assert(sd_rtnl_message_exit_container(m) == -EINVAL); } static void test_match(void) { @@ -286,7 +300,7 @@ int main(void) { assert(sd_rtnl_message_get_type(m, &type) >= 0); assert(type == RTM_GETLINK); - assert(sd_rtnl_message_read(m, &type, &data) == 0); + assert(sd_rtnl_message_read(m, &type, &data) == -EPERM); assert(sd_rtnl_call(rtnl, m, 0, &r) == 1); assert(sd_rtnl_message_get_type(r, &type) >= 0); @@ -303,6 +317,8 @@ int main(void) { assert(m); assert(sd_rtnl_message_append_u32(m, IFLA_MTU, mtu) >= 0); + assert(sd_rtnl_message_read(m, &type, (void **) &mtu_reply) == -EPERM); + assert(sd_rtnl_call(rtnl, m, -1, &r) == 1); assert(sd_rtnl_message_read(m, &type, (void **) &mtu_reply) == 1); assert(type == IFLA_MTU); @@ -310,7 +326,6 @@ int main(void) { assert(sd_rtnl_message_read(m, &type, &data) == 0); - assert(sd_rtnl_call(rtnl, m, -1, &r) == 1); while (sd_rtnl_message_read(r, &type, &data) > 0) { switch (type) { // case IFLA_MTU: diff --git a/src/systemd/sd-rtnl.h b/src/systemd/sd-rtnl.h index 5539e2315..c54533392 100644 --- a/src/systemd/sd-rtnl.h +++ b/src/systemd/sd-rtnl.h @@ -105,6 +105,7 @@ 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); +int sd_rtnl_message_exit_container(sd_rtnl_message *m); int sd_rtnl_message_rewind(sd_rtnl_message *m); -- 2.30.2