libvirt/src/util/virbpf.c
Michal Privoznik 95b9db4ee2 lib: Prefer WITH_* prefix for #if conditionals
Currently, we are mixing: #if HAVE_BLAH with #if WITH_BLAH.
Things got way better with Pavel's work on meson, but apparently,
mixing these two lead to confusing and easy to miss bugs (see
31fb929eca for instance). While we were forced to use HAVE_
prefix with autotools, we are free to chose our own prefix with
meson and since WITH_ prefix appears to be more popular let's use
it everywhere.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2020-09-02 10:28:10 +02:00

425 lines
8.6 KiB
C

/*
* virbpf.c: methods for eBPF
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include "virlog.h"
#include "virerror.h"
#include "virbpf.h"
VIR_LOG_INIT("util.bpf");
#define VIR_FROM_THIS VIR_FROM_BPF
#if WITH_SYS_SYSCALL_H && WITH_DECL_BPF_PROG_QUERY
# include <sys/syscall.h>
# include <unistd.h>
int
virBPFCreateMap(unsigned int mapType,
unsigned int keySize,
unsigned int valSize,
unsigned int maxEntries)
{
union bpf_attr attr;
memset(&attr, 0, sizeof(attr));
attr.map_type = mapType;
attr.key_size = keySize;
attr.value_size = valSize;
attr.max_entries = maxEntries;
return syscall(SYS_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
}
# define LOG_BUF_SIZE (256 * 1024)
int
virBPFLoadProg(struct bpf_insn *insns,
int progType,
unsigned int insnCnt)
{
g_autofree char *logbuf = NULL;
int progfd = -1;
union bpf_attr attr;
logbuf = g_new0(char, LOG_BUF_SIZE);
memset(&attr, 0, sizeof(attr));
attr.prog_type = progType;
attr.insn_cnt = insnCnt;
attr.insns = (uintptr_t)insns;
attr.license = (uintptr_t)"GPL";
attr.log_buf = (uintptr_t)logbuf;
attr.log_size = LOG_BUF_SIZE;
attr.log_level = 1;
progfd = syscall(SYS_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
if (progfd < 0)
VIR_DEBUG("%s", logbuf);
return progfd;
}
int
virBPFAttachProg(int progfd,
int targetfd,
int attachType)
{
union bpf_attr attr;
memset(&attr, 0, sizeof(attr));
attr.target_fd = targetfd;
attr.attach_bpf_fd = progfd;
attr.attach_type = attachType;
return syscall(SYS_bpf, BPF_PROG_ATTACH, &attr, sizeof(attr));
}
int
virBPFDetachProg(int progfd,
int targetfd,
int attachType)
{
union bpf_attr attr;
memset(&attr, 0, sizeof(attr));
attr.target_fd = targetfd;
attr.attach_bpf_fd = progfd;
attr.attach_type = attachType;
return syscall(SYS_bpf, BPF_PROG_DETACH, &attr, sizeof(attr));
}
int
virBPFQueryProg(int targetfd,
unsigned int maxprogids,
int attachType,
unsigned int *progcnt,
void *progids)
{
union bpf_attr attr;
int rc;
memset(&attr, 0, sizeof(attr));
attr.query.target_fd = targetfd;
attr.query.attach_type = attachType;
attr.query.prog_cnt = maxprogids;
attr.query.prog_ids = (uintptr_t)progids;
rc = syscall(SYS_bpf, BPF_PROG_QUERY, &attr, sizeof(attr));
if (rc >= 0)
*progcnt = attr.query.prog_cnt;
return rc;
}
int
virBPFGetProg(unsigned int id)
{
union bpf_attr attr;
memset(&attr, 0, sizeof(attr));
attr.prog_id = id;
return syscall(SYS_bpf, BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr));
}
int
virBPFGetProgInfo(int progfd,
struct bpf_prog_info *info,
unsigned int **mapIDs)
{
union bpf_attr attr;
int rc;
memset(&attr, 0, sizeof(attr));
attr.info.bpf_fd = progfd;
attr.info.info_len = sizeof(struct bpf_prog_info);
attr.info.info = (uintptr_t)info;
rc = syscall(SYS_bpf, BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr));
if (rc < 0)
return rc;
if (mapIDs && info->nr_map_ids > 0) {
unsigned int maplen = info->nr_map_ids;
g_autofree unsigned int *retmapIDs = NULL;
retmapIDs = g_new0(unsigned int, maplen);
memset(info, 0, sizeof(struct bpf_prog_info));
info->nr_map_ids = maplen;
info->map_ids = (uintptr_t)retmapIDs;
memset(&attr, 0, sizeof(attr));
attr.info.bpf_fd = progfd;
attr.info.info_len = sizeof(struct bpf_prog_info);
attr.info.info = (uintptr_t)info;
rc = syscall(SYS_bpf, BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr));
if (rc < 0)
return rc;
*mapIDs = g_steal_pointer(&retmapIDs);
}
return rc;
}
int
virBPFGetMap(unsigned int id)
{
union bpf_attr attr;
memset(&attr, 0, sizeof(attr));
attr.map_id = id;
return syscall(SYS_bpf, BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr));
}
int
virBPFGetMapInfo(int mapfd,
struct bpf_map_info *info)
{
union bpf_attr attr;
memset(&attr, 0, sizeof(attr));
attr.info.bpf_fd = mapfd;
attr.info.info_len = sizeof(struct bpf_map_info);
attr.info.info = (uintptr_t)info;
return syscall(SYS_bpf, BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr));
}
int
virBPFLookupElem(int mapfd,
void *key,
void *val)
{
union bpf_attr attr;
memset(&attr, 0, sizeof(attr));
attr.map_fd = mapfd;
attr.key = (uintptr_t)key;
attr.value = (uintptr_t)val;
return syscall(SYS_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
}
int
virBPFGetNextElem(int mapfd,
void *key,
void *nextKey)
{
union bpf_attr attr;
memset(&attr, 0, sizeof(attr));
attr.map_fd = mapfd;
attr.key = (uintptr_t)key;
attr.next_key = (uintptr_t)nextKey;
return syscall(SYS_bpf, BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
}
int
virBPFUpdateElem(int mapfd,
void *key,
void *val)
{
union bpf_attr attr;
memset(&attr, 0, sizeof(attr));
attr.map_fd = mapfd;
attr.key = (uintptr_t)key;
attr.value = (uintptr_t)val;
return syscall(SYS_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
}
int
virBPFDeleteElem(int mapfd,
void *key)
{
union bpf_attr attr;
memset(&attr, 0, sizeof(attr));
attr.map_fd = mapfd;
attr.key = (uintptr_t)key;
return syscall(SYS_bpf, BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
}
#else /* !WITH_SYS_SYSCALL_H || !WITH_DECL_BPF_PROG_QUERY */
int
virBPFCreateMap(unsigned int mapType G_GNUC_UNUSED,
unsigned int keySize G_GNUC_UNUSED,
unsigned int valSize G_GNUC_UNUSED,
unsigned int maxEntries G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFLoadProg(struct bpf_insn *insns G_GNUC_UNUSED,
int progType G_GNUC_UNUSED,
unsigned int insnCnt G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFAttachProg(int progfd G_GNUC_UNUSED,
int targetfd G_GNUC_UNUSED,
int attachType G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFDetachProg(int progfd G_GNUC_UNUSED,
int targetfd G_GNUC_UNUSED,
int attachType G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFQueryProg(int targetfd G_GNUC_UNUSED,
unsigned int maxprogids G_GNUC_UNUSED,
int attachType G_GNUC_UNUSED,
unsigned int *progcnt G_GNUC_UNUSED,
void *progids G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFGetProg(unsigned int id G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFGetProgInfo(int progfd G_GNUC_UNUSED,
struct bpf_prog_info *info G_GNUC_UNUSED,
unsigned int **mapIDs G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFGetMap(unsigned int id G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFGetMapInfo(int mapfd G_GNUC_UNUSED,
struct bpf_map_info *info G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFLookupElem(int mapfd G_GNUC_UNUSED,
void *key G_GNUC_UNUSED,
void *val G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFGetNextElem(int mapfd G_GNUC_UNUSED,
void *key G_GNUC_UNUSED,
void *nextKey G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFUpdateElem(int mapfd G_GNUC_UNUSED,
void *key G_GNUC_UNUSED,
void *val G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
int
virBPFDeleteElem(int mapfd G_GNUC_UNUSED,
void *key G_GNUC_UNUSED)
{
errno = ENOSYS;
return -1;
}
#endif /* !WITH_SYS_SYSCALL_H || !WITH_DECL_BPF_PROG_QUERY */