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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 02:57:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 02:57:58 +0000 |
commit | be1c7e50e1e8809ea56f2c9d472eccd8ffd73a97 (patch) | |
tree | 9754ff1ca740f6346cf8483ec915d4054bc5da2d /libnetdata/log/journal.c | |
parent | Initial commit. (diff) | |
download | netdata-be1c7e50e1e8809ea56f2c9d472eccd8ffd73a97.tar.xz netdata-be1c7e50e1e8809ea56f2c9d472eccd8ffd73a97.zip |
Adding upstream version 1.44.3.upstream/1.44.3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'libnetdata/log/journal.c')
-rw-r--r-- | libnetdata/log/journal.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/libnetdata/log/journal.c b/libnetdata/log/journal.c new file mode 100644 index 00000000..21978cf5 --- /dev/null +++ b/libnetdata/log/journal.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#include "journal.h" + +bool is_path_unix_socket(const char *path) { + if(!path || !*path) + return false; + + struct stat statbuf; + + // Check if the path is valid + if (!path || !*path) + return false; + + // Use stat to check if the file exists and is a socket + if (stat(path, &statbuf) == -1) + // The file does not exist or cannot be accessed + return false; + + // Check if the file is a socket + if (S_ISSOCK(statbuf.st_mode)) + return true; + + return false; +} + +bool is_stderr_connected_to_journal(void) { + const char *journal_stream = getenv("JOURNAL_STREAM"); + if (!journal_stream) + return false; // JOURNAL_STREAM is not set + + struct stat stderr_stat; + if (fstat(STDERR_FILENO, &stderr_stat) < 0) + return false; // Error in getting stderr info + + // Parse device and inode from JOURNAL_STREAM + char *endptr; + long journal_dev = strtol(journal_stream, &endptr, 10); + if (*endptr != ':') + return false; // Format error in JOURNAL_STREAM + + long journal_ino = strtol(endptr + 1, NULL, 10); + + return (stderr_stat.st_dev == (dev_t)journal_dev) && (stderr_stat.st_ino == (ino_t)journal_ino); +} + +int journal_direct_fd(const char *path) { + if(!path || !*path) + path = JOURNAL_DIRECT_SOCKET; + + if(!is_path_unix_socket(path)) + return -1; + + int fd = socket(AF_UNIX, SOCK_DGRAM, 0); + if (fd < 0) return -1; + + struct sockaddr_un addr; + memset(&addr, 0, sizeof(struct sockaddr_un)); + addr.sun_family = AF_UNIX; + strncpy(addr.sun_path, path, sizeof(addr.sun_path) - 1); + + // Connect the socket (optional, but can simplify send operations) + if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) { + close(fd); + return -1; + } + + return fd; +} + +static inline bool journal_send_with_memfd(int fd, const char *msg, size_t msg_len) { +#if defined(__NR_memfd_create) && defined(MFD_ALLOW_SEALING) && defined(F_ADD_SEALS) && defined(F_SEAL_SHRINK) && defined(F_SEAL_GROW) && defined(F_SEAL_WRITE) + // Create a memory file descriptor + int memfd = (int)syscall(__NR_memfd_create, "journald", MFD_ALLOW_SEALING); + if (memfd < 0) return false; + + // Write data to the memfd + if (write(memfd, msg, msg_len) != (ssize_t)msg_len) { + close(memfd); + return false; + } + + // Seal the memfd to make it immutable + if (fcntl(memfd, F_ADD_SEALS, F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE) < 0) { + close(memfd); + return false; + } + + struct iovec iov = {0}; + struct msghdr msghdr = {0}; + struct cmsghdr *cmsghdr; + char cmsgbuf[CMSG_SPACE(sizeof(int))]; + + msghdr.msg_iov = &iov; + msghdr.msg_iovlen = 1; + msghdr.msg_control = cmsgbuf; + msghdr.msg_controllen = sizeof(cmsgbuf); + + cmsghdr = CMSG_FIRSTHDR(&msghdr); + cmsghdr->cmsg_level = SOL_SOCKET; + cmsghdr->cmsg_type = SCM_RIGHTS; + cmsghdr->cmsg_len = CMSG_LEN(sizeof(int)); + memcpy(CMSG_DATA(cmsghdr), &memfd, sizeof(int)); + + ssize_t r = sendmsg(fd, &msghdr, 0); + + close(memfd); + return r >= 0; +#else + return false; +#endif +} + +bool journal_direct_send(int fd, const char *msg, size_t msg_len) { + // Send the datagram + if (send(fd, msg, msg_len, 0) < 0) { + if(errno != EMSGSIZE) + return false; + + // datagram is too large, fallback to memfd + if(!journal_send_with_memfd(fd, msg, msg_len)) + return false; + } + + return true; +} + +void journal_construct_path(char *dst, size_t dst_len, const char *host_prefix, const char *namespace_str) { + if(!host_prefix) + host_prefix = ""; + + if(namespace_str) + snprintfz(dst, dst_len, "%s/run/systemd/journal.%s/socket", + host_prefix, namespace_str); + else + snprintfz(dst, dst_len, "%s" JOURNAL_DIRECT_SOCKET, + host_prefix); +} |