From 4dc766fa8a92a9862c3f9d560751a941b4599380 Mon Sep 17 00:00:00 2001 From: =?utf8?q?J=C3=A9r=C3=A9mie=20Galarneau?= Date: Wed, 14 Jul 2021 15:19:15 -0400 Subject: [PATCH] Build fix: retrieve unix socket peer PID on non-unix platforms MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The previous attempt at extending the credential retrieval wrapper was broken and didn't build on FreeBSD, macOS, and cygwin. A platform-specific way of retrieving the PID of a unix peer is implemented for FreeBSD (getsockopt using LOCAL_PEERCRED, note that the cr_pid field is only available from FreeBSD 13 and up), macOS (getsockopt using LOCAL_PEERPID, macOS 10.8+), and Solaris (getpeerucreds). Signed-off-by: Jérémie Galarneau Change-Id: Ifcf522c70ee4c2e0799293ae0961f41aebff5056 --- src/common/compat/socket.h | 156 +++++++++++++++++++++++++++---------- src/common/unix.c | 37 ++++----- 2 files changed, 132 insertions(+), 61 deletions(-) diff --git a/src/common/compat/socket.h b/src/common/compat/socket.h index 464678292..fda00e536 100644 --- a/src/common/compat/socket.h +++ b/src/common/compat/socket.h @@ -10,6 +10,7 @@ #include #include +#include #include @@ -97,8 +98,58 @@ ssize_t lttng_recvmsg_nosigpipe(int sockfd, struct msghdr *msg) } #endif +#ifdef __sun__ + +# ifndef CMSG_ALIGN +# ifdef _CMSG_DATA_ALIGN +# define CMSG_ALIGN(len) _CMSG_DATA_ALIGN(len) +# else + /* aligning to sizeof (long) is assumed to be portable (fd.o#40235) */ +# define CMSG_ALIGN(len) (((len) + sizeof (long) - 1) & ~(sizeof (long) - 1)) +# endif +# ifndef CMSG_SPACE +# define CMSG_SPACE(len) (CMSG_ALIGN (sizeof (struct cmsghdr)) + CMSG_ALIGN (len)) +# endif +# ifndef CMSG_LEN +# define CMSG_LEN(len) (CMSG_ALIGN (sizeof (struct cmsghdr)) + (len)) +# endif +# endif + +#include -#ifdef __linux__ +static inline +int getpeereid(int s, uid_t *euid, gid_t *gid) +{ + int ret = 0; + ucred_t *ucred = NULL; + + ret = getpeerucred(s, &ucred); + if (ret == -1) { + goto end; + } + + ret = ucred_geteuid(ucred); + if (ret == -1) { + goto free; + } + *euid = ret; + + ret = ucred_getrgid(ucred); + if (ret == -1) { + goto free; + } + *gid = ret; + + ret = 0; +free: + ucred_free(ucred); +end: + return ret; +} +#endif /* __sun__ */ + + +#if defined(__linux__) || defined(__CYGWIN__) #define LTTNG_SOCK_CREDS SCM_CREDENTIALS @@ -112,7 +163,7 @@ typedef struct ucred lttng_sock_cred; #define LTTNG_SOCK_GET_GID_CRED(c) LTTNG_REF(c)->gid #define LTTNG_SOCK_GET_PID_CRED(c) LTTNG_REF(c)->pid -#elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__)) +#elif (defined(__FreeBSD__) || defined(__sun__) || defined(__APPLE__)) struct lttng_sock_cred { uid_t uid; @@ -124,39 +175,27 @@ typedef struct lttng_sock_cred lttng_sock_cred; #define LTTNG_SOCK_SET_UID_CRED(c, u) LTTNG_REF(c)->uid = u #define LTTNG_SOCK_SET_GID_CRED(c, g) LTTNG_REF(c)->gid = g -#define LTTNG_SOCK_SET_PID_CRED(c, p) +#define LTTNG_SOCK_SET_PID_CRED(c, p) LTTNG_REF(c)->pid = p #define LTTNG_SOCK_GET_UID_CRED(c) LTTNG_REF(c)->uid #define LTTNG_SOCK_GET_GID_CRED(c) LTTNG_REF(c)->gid -#define LTTNG_SOCK_GET_PID_CRED(c) -1 - -#else -#error "Please add support for your OS." -#endif /* __linux__ , __FreeBSD__ */ - - -#ifdef __sun__ +#define LTTNG_SOCK_GET_PID_CRED(c) LTTNG_REF(c)->pid -# ifndef CMSG_ALIGN -# ifdef _CMSG_DATA_ALIGN -# define CMSG_ALIGN(len) _CMSG_DATA_ALIGN(len) -# else - /* aligning to sizeof (long) is assumed to be portable (fd.o#40235) */ -# define CMSG_ALIGN(len) (((len) + sizeof (long) - 1) & ~(sizeof (long) - 1)) -# endif -# ifndef CMSG_SPACE -# define CMSG_SPACE(len) (CMSG_ALIGN (sizeof (struct cmsghdr)) + CMSG_ALIGN (len)) -# endif -# ifndef CMSG_LEN -# define CMSG_LEN(len) (CMSG_ALIGN (sizeof (struct cmsghdr)) + (len)) -# endif -# endif +#ifdef __APPLE__ +static inline +int lttng_get_unix_socket_peer_pid(int socket_fd, pid_t *pid) +{ + /* The getsockopt LOCAL_PEERPID option is available since macOS 10.8. */ + return getsockopt(socket_fd, SOL_LOCAL, LOCAL_PEERPID, pid, + &((socklen_t) {sizeof(*pid)})); +} -#include +#elif defined(__sun__) +/* Use the getpeerucreds interface on Solaris. */ static inline -int getpeereid(int s, uid_t *euid, gid_t *gid, pid_t *pid) +int lttng_get_unix_socket_peer_pid(int socket_fd, pid_t *pid) { int ret = 0; ucred_t *ucred = NULL; @@ -166,24 +205,12 @@ int getpeereid(int s, uid_t *euid, gid_t *gid, pid_t *pid) goto end; } - ret = ucred_geteuid(ucred); - if (ret == -1) { - goto free; - } - *euid = ret; - - ret = ucred_getrgid(ucred); - if (ret == -1) { - goto free; - } - *gid = ret; - ret = ucred_getpid(ucred); if (ret == -1) { goto free; } - *pid = ret; + *pid = ret; ret = 0; free: ucred_free(ucred); @@ -191,6 +218,53 @@ end: return ret; } -#endif /* __sun__ */ +#elif defined(__FreeBSD__) + +#include + +static inline +int lttng_get_unix_socket_peer_pid(int socket_fd, pid_t *pid) +{ + int ret; + struct xucred sock_creds = {}; + + /* Only available in FreeBSD 13.0 and up. */ + ret = getsockopt(socket_fd, SOL_LOCAL, LOCAL_PEERCRED, &sock_creds, + &((socklen_t) {sizeof(sock_creds)})); + if (ret) { + goto end; + } + + *pid = sock_creds.cr_pid; +end: + return ret; +} + +#endif /* __APPLE__ */ + + +static inline +int lttng_get_unix_socket_peer_creds(int socket_fd, struct lttng_sock_cred *creds) +{ + int ret; + + /* This is a BSD extension that is supported by Cygwin. */ + ret = getpeereid(socket_fd, &creds->uid, &creds->gid); + if (ret) { + goto end; + } + + /* + * Getting a peer's PID is a bit more troublesome as it is platform + * specific. + */ + ret = lttng_get_unix_socket_peer_pid(socket_fd, &creds->pid); +end: + return ret; +} + +#else +#error "Please add support for your OS." +#endif /* __linux__ , __FreeBSD__, __APPLE__ */ #endif /* _COMPAT_SOCKET_H */ diff --git a/src/common/unix.c b/src/common/unix.c index 12622e5dd..4c5c7acc6 100644 --- a/src/common/unix.c +++ b/src/common/unix.c @@ -992,14 +992,14 @@ ssize_t lttcomm_send_creds_unix_sock(int sock, const void *buf, size_t len) struct msghdr msg; struct iovec iov[1]; ssize_t ret = -1; -#ifdef __linux__ +#if defined(__linux__) || defined(__CYGWIN__) struct cmsghdr *cmptr; size_t sizeof_cred = sizeof(lttng_sock_cred); char anc_buf[CMSG_SPACE(sizeof_cred)]; lttng_sock_cred *creds; memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char)); -#endif /* __linux__ */ +#endif /* __linux__, __CYGWIN__ */ memset(&msg, 0, sizeof(msg)); @@ -1012,7 +1012,7 @@ ssize_t lttcomm_send_creds_unix_sock(int sock, const void *buf, size_t len) msg.msg_iov = iov; msg.msg_iovlen = 1; -#ifdef __linux__ +#if defined(__linux__) || defined(__CYGWIN__) msg.msg_control = (caddr_t) anc_buf; msg.msg_controllen = CMSG_LEN(sizeof_cred); @@ -1029,7 +1029,7 @@ ssize_t lttcomm_send_creds_unix_sock(int sock, const void *buf, size_t len) LTTNG_SOCK_SET_UID_CRED(creds, geteuid()); LTTNG_SOCK_SET_GID_CRED(creds, getegid()); LTTNG_SOCK_SET_PID_CRED(creds, getpid()); -#endif /* __linux__ */ +#endif /* __linux__, __CYGWIN__ */ do { ret = sendmsg(sock, &msg, 0); @@ -1059,11 +1059,11 @@ ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len, struct iovec iov[1]; ssize_t ret; size_t len_last; -#ifdef __linux__ +#if defined(__linux__) || defined(__CYGWIN__) struct cmsghdr *cmptr; size_t sizeof_cred = sizeof(lttng_sock_cred); char anc_buf[CMSG_SPACE(sizeof_cred)]; -#endif /* __linux__ */ +#endif /* __linux__, __CYGWIN__ */ assert(sock); assert(buf); @@ -1078,10 +1078,10 @@ ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len, msg.msg_iov = iov; msg.msg_iovlen = 1; -#ifdef __linux__ +#if defined(__linux__) || defined(__CYGWIN__) msg.msg_control = anc_buf; msg.msg_controllen = sizeof(anc_buf); -#endif /* __linux__ */ +#endif /* __linux__, __CYGWIN__ */ do { len_last = iov[0].iov_len; @@ -1100,7 +1100,7 @@ ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len, } /* Else ret = 0 meaning an orderly shutdown. */ -#ifdef __linux__ +#if defined(__linux__) || defined(__CYGWIN__) if (msg.msg_flags & MSG_CTRUNC) { fprintf(stderr, "Error: Control message truncated.\n"); ret = -1; @@ -1129,18 +1129,15 @@ ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len, } memcpy(creds, CMSG_DATA(cmptr), sizeof_cred); -#elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__)) - { - int peer_ret; - - peer_ret = getpeereid(sock, &creds->uid, &creds->gid, &creds->pid); - if (peer_ret != 0) { - return peer_ret; - } +#elif (defined(__FreeBSD__) || defined(__sun__) || defined(__APPLE__)) + if (lttng_get_unix_socket_peer_creds(sock, creds)) { + fprintf(stderr, "ARG\n"); + ret = -1; + goto end; } #else #error "Please implement credential support for your OS." -#endif /* __linux__ */ +#endif /* __linux__, __CYGWIN__ */ end: return ret; @@ -1149,7 +1146,7 @@ end: /* * Set socket option to use credentials passing. */ -#ifdef __linux__ +#if defined(__linux__) || defined(__CYGWIN__) LTTNG_HIDDEN int lttcomm_setsockopt_creds_unix_sock(int sock) { @@ -1162,7 +1159,7 @@ int lttcomm_setsockopt_creds_unix_sock(int sock) } return ret; } -#elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__)) +#elif (defined(__FreeBSD__) || defined(__sun__) || defined(__APPLE__)) LTTNG_HIDDEN int lttcomm_setsockopt_creds_unix_sock(int sock) { -- 2.34.1