X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust-comm%2Flttng-ust-comm.c;h=f469567690b3a9a88a2d7f4252417e130a1c6975;hb=74d81a6cca2cd4a7718bba9368f382f9f2fbba84;hp=db9910ded9c3fcf2a660fa77c5a35851df07fdc8;hpb=00b217e613614b8addc4ee2bbcdec473275842fd;p=lttng-ust.git diff --git a/liblttng-ust-comm/lttng-ust-comm.c b/liblttng-ust-comm/lttng-ust-comm.c index db9910de..f4695676 100644 --- a/liblttng-ust-comm/lttng-ust-comm.c +++ b/liblttng-ust-comm/lttng-ust-comm.c @@ -1,6 +1,6 @@ /* * Copyright (C) 2011 - David Goulet - * Copyright (C) 2011 - Mathieu Desnoyers + * Copyright (C) 2011-2013 - Mathieu Desnoyers * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -32,11 +32,14 @@ #include #include +#include #include #define USTCOMM_CODE_OFFSET(code) \ (code == LTTNG_UST_OK ? 0 : (code - LTTNG_UST_ERR + 1)) +#define USTCOMM_MAX_SEND_FDS 4 + /* * Human readable error message. */ @@ -48,6 +51,7 @@ static const char *ustcomm_readable_code[] = { [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_INVAL) ] = "Invalid argument", [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_PERM) ] = "Permission denied", [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_NOSYS) ] = "Not implemented", + [ USTCOMM_CODE_OFFSET(LTTNG_UST_ERR_EXITING) ] = "Process is exiting", }; /* @@ -70,9 +74,9 @@ const char *lttng_ust_strerror(int code) } /* - * ustcomm_connect_unix_sock + * ustcomm_connect_unix_sock * - * Connect to unix socket using the path name. + * Connect to unix socket using the path name. */ int ustcomm_connect_unix_sock(const char *pathname) { @@ -128,10 +132,10 @@ error: } /* - * ustcomm_accept_unix_sock + * ustcomm_accept_unix_sock * - * Do an accept(2) on the sock and return the - * new file descriptor. The socket MUST be bind(2) before. + * Do an accept(2) on the sock and return the + * new file descriptor. The socket MUST be bind(2) before. */ int ustcomm_accept_unix_sock(int sock) { @@ -149,10 +153,10 @@ int ustcomm_accept_unix_sock(int sock) } /* - * ustcomm_create_unix_sock + * ustcomm_create_unix_sock * - * Creates a AF_UNIX local socket using pathname - * bind the socket upon creation and return the fd. + * Creates a AF_UNIX local socket using pathname + * bind the socket upon creation and return the fd. */ int ustcomm_create_unix_sock(const char *pathname) { @@ -196,9 +200,9 @@ error: } /* - * ustcomm_listen_unix_sock + * ustcomm_listen_unix_sock * - * Make the socket listen using LTTNG_UST_COMM_MAX_LISTEN. + * Make the socket listen using LTTNG_UST_COMM_MAX_LISTEN. */ int ustcomm_listen_unix_sock(int sock) { @@ -214,11 +218,30 @@ int ustcomm_listen_unix_sock(int sock) } /* - * ustcomm_recv_unix_sock + * ustcomm_close_unix_sock + * + * Shutdown cleanly a unix socket. + */ +int ustcomm_close_unix_sock(int sock) +{ + int ret; + + ret = close(sock); + if (ret < 0) { + perror("close"); + ret = -errno; + } + + return ret; +} + +/* + * ustcomm_recv_unix_sock * - * Receive data of size len in put that data into - * the buf param. Using recvmsg API. - * Return the size of received data. + * Receive data of size len in put that data into + * the buf param. Using recvmsg API. + * Return the size of received data. + * Return 0 on orderly shutdown. */ ssize_t ustcomm_recv_unix_sock(int sock, void *buf, size_t len) { @@ -240,7 +263,7 @@ ssize_t ustcomm_recv_unix_sock(int sock, void *buf, size_t len) if (ret < 0) { int shutret; - if (errno != EPIPE) + if (errno != EPIPE && errno != ECONNRESET) perror("recvmsg"); ret = -errno; @@ -253,10 +276,10 @@ ssize_t ustcomm_recv_unix_sock(int sock, void *buf, size_t len) } /* - * ustcomm_send_unix_sock + * ustcomm_send_unix_sock * - * Send buf data of size len. Using sendmsg API. - * Return the size of sent data. + * Send buf data of size len. Using sendmsg API. + * Return the size of sent data. */ ssize_t ustcomm_send_unix_sock(int sock, void *buf, size_t len) { @@ -285,8 +308,8 @@ ssize_t ustcomm_send_unix_sock(int sock, void *buf, size_t len) if (ret < 0) { int shutret; - if (errno != EPIPE) - perror("recvmsg"); + if (errno != EPIPE && errno != ECONNRESET) + perror("sendmsg"); ret = -errno; shutret = shutdown(sock, SHUT_RDWR); @@ -298,29 +321,11 @@ ssize_t ustcomm_send_unix_sock(int sock, void *buf, size_t len) } /* - * ustcomm_close_unix_sock + * Send a message accompanied by fd(s) over a unix socket. * - * Shutdown cleanly a unix socket. + * Returns the size of data sent, or negative error value. */ -int ustcomm_close_unix_sock(int sock) -{ - int ret; - - ret = close(sock); - if (ret < 0) { - perror("close"); - ret = -errno; - } - - return ret; -} - -/* - * ustcomm_send_fds_unix_sock - * - * Send multiple fds on a unix socket. - */ -ssize_t ustcomm_send_fds_unix_sock(int sock, void *buf, int *fds, size_t nb_fd, size_t len) +ssize_t ustcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd) { struct msghdr msg; struct cmsghdr *cmptr; @@ -328,14 +333,13 @@ ssize_t ustcomm_send_fds_unix_sock(int sock, void *buf, int *fds, size_t nb_fd, ssize_t ret = -1; unsigned int sizeof_fds = nb_fd * sizeof(int); char tmp[CMSG_SPACE(sizeof_fds)]; + char dummy = 0; memset(&msg, 0, sizeof(msg)); + memset(tmp, 0, CMSG_SPACE(sizeof_fds) * sizeof(char)); - /* - * Note: we currently only support sending a single FD per - * message. - */ - assert(nb_fd == 1); + if (nb_fd > USTCOMM_MAX_SEND_FDS) + return -EINVAL; msg.msg_control = (caddr_t)tmp; msg.msg_controllen = CMSG_LEN(sizeof_fds); @@ -348,27 +352,100 @@ ssize_t ustcomm_send_fds_unix_sock(int sock, void *buf, int *fds, size_t nb_fd, /* Sum of the length of all control messages in the buffer: */ msg.msg_controllen = cmptr->cmsg_len; - iov[0].iov_base = buf; - iov[0].iov_len = len; + iov[0].iov_base = &dummy; + iov[0].iov_len = 1; msg.msg_iov = iov; msg.msg_iovlen = 1; do { - ret = sendmsg(sock, &msg, MSG_NOSIGNAL); + ret = sendmsg(sock, &msg, 0); } while (ret < 0 && errno == EINTR); - if (ret < 0) { - int shutret; + /* + * We consider EPIPE and ECONNRESET as expected. + */ + if (errno != EPIPE && errno != ECONNRESET) { + perror("sendmsg"); + } + } + return ret; +} - if (errno != EPIPE) - perror("recvmsg"); - ret = -errno; +/* + * Recv a message accompanied by fd(s) from a unix socket. + * + * Returns the size of received data, or negative error value. + * + * Expect at most "nb_fd" file descriptors. Returns the number of fd + * actually received in nb_fd. + * Returns -EPIPE on orderly shutdown. + */ +ssize_t ustcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd) +{ + struct iovec iov[1]; + ssize_t ret = 0; + struct cmsghdr *cmsg; + size_t sizeof_fds = nb_fd * sizeof(int); + char recv_fd[CMSG_SPACE(sizeof_fds)]; + struct msghdr msg; + char dummy; - shutret = shutdown(sock, SHUT_RDWR); - if (shutret) - fprintf(stderr, "Socket shutdown error"); - } + memset(&msg, 0, sizeof(msg)); + /* Prepare to receive the structures */ + iov[0].iov_base = &dummy; + iov[0].iov_len = 1; + msg.msg_iov = iov; + msg.msg_iovlen = 1; + msg.msg_control = recv_fd; + msg.msg_controllen = sizeof(recv_fd); + + do { + ret = recvmsg(sock, &msg, 0); + } while (ret < 0 && errno == EINTR); + if (ret < 0) { + if (errno != EPIPE && errno != ECONNRESET) { + perror("recvmsg fds"); + } + if (errno == EPIPE || errno == ECONNRESET) + ret = -errno; + goto end; + } + if (ret == 0) { + /* orderly shutdown */ + ret = -EPIPE; + goto end; + } + if (ret != 1) { + fprintf(stderr, "Error: Received %zd bytes, expected %d\n", + ret, 1); + goto end; + } + if (msg.msg_flags & MSG_CTRUNC) { + fprintf(stderr, "Error: Control message truncated.\n"); + ret = -1; + goto end; + } + cmsg = CMSG_FIRSTHDR(&msg); + if (!cmsg) { + fprintf(stderr, "Error: Invalid control message header\n"); + ret = -1; + goto end; + } + if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) { + fprintf(stderr, "Didn't received any fd\n"); + ret = -1; + goto end; + } + if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) { + fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n", + (size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds)); + ret = -1; + goto end; + } + memcpy(fds, CMSG_DATA(cmsg), sizeof_fds); + ret = sizeof_fds; +end: return ret; } @@ -382,8 +459,6 @@ int ustcomm_send_app_msg(int sock, struct ustcomm_ust_msg *lum) break; default: if (len < 0) { - if (len == -ECONNRESET) - fprintf(stderr, "remote end closed connection\n"); return len; } else { fprintf(stderr, "incorrect message size: %zd\n", len); @@ -402,22 +477,26 @@ int ustcomm_recv_app_reply(int sock, struct ustcomm_ust_reply *lur, len = ustcomm_recv_unix_sock(sock, lur, sizeof(*lur)); switch (len) { case 0: /* orderly shutdown */ - return -EINVAL; + return -EPIPE; case sizeof(*lur): if (lur->handle != expected_handle) { - fprintf(stderr, "Unexpected result message handle\n"); + fprintf(stderr, "Unexpected result message handle: " + "expected: %u vs received: %u\n", + expected_handle, lur->handle); return -EINVAL; } if (lur->cmd != expected_cmd) { - fprintf(stderr, "Unexpected result message command\n"); + fprintf(stderr, "Unexpected result message command " + "expected: %u vs received: %u\n", + expected_cmd, lur->cmd); return -EINVAL; } return lur->ret_code; default: if (len < 0) { /* Transport level error */ - if (len == -ECONNRESET) - fprintf(stderr, "remote end closed connection\n"); + if (errno == EPIPE || errno == ECONNRESET) + len = -errno; return len; } else { fprintf(stderr, "incorrect message size: %zd\n", len); @@ -442,76 +521,62 @@ int ustcomm_send_app_cmd(int sock, } /* - * Receives a single fd from socket. - * - * Returns negative error value on error, or file descriptor number on - * success. + * chan_data is allocated internally if this function returns the + * expected var_len. */ -int ustcomm_recv_fd(int sock) +ssize_t ustcomm_recv_channel_from_sessiond(int sock, + void **_chan_data, uint64_t var_len) { - struct iovec iov[1]; - int ret = 0; - int data_fd; - struct cmsghdr *cmsg; - char recv_fd[CMSG_SPACE(sizeof(int))]; - struct msghdr msg; - union { - unsigned char vc[4]; - int vi; - } tmp; - int i; - - memset(&msg, 0, sizeof(msg)); - - /* Prepare to receive the structures */ - iov[0].iov_base = &data_fd; - iov[0].iov_len = sizeof(data_fd); - msg.msg_iov = iov; - msg.msg_iovlen = 1; - msg.msg_control = recv_fd; - msg.msg_controllen = sizeof(recv_fd); + void *chan_data; + ssize_t len; - do { - ret = recvmsg(sock, &msg, 0); - } while (ret < 0 && errno == EINTR); - if (ret < 0) { - if (errno != EPIPE) { - perror("recvmsg"); - } - ret = -errno; - goto end; - } - if (ret != sizeof(data_fd)) { - fprintf(stderr, "Received %d bytes, expected %zd", ret, sizeof(data_fd)); - ret = -EINVAL; - goto end; + if (var_len > LTTNG_UST_CHANNEL_DATA_MAX_LEN) { + len = -EINVAL; + goto error_check; } - cmsg = CMSG_FIRSTHDR(&msg); - if (!cmsg) { - fprintf(stderr, "Invalid control message header\n"); - ret = -EINVAL; - goto end; + /* Receive variable length data */ + chan_data = zmalloc(var_len); + if (!chan_data) { + len = -ENOMEM; + goto error_alloc; } - if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) { - fprintf(stderr, "Didn't received any fd\n"); - ret = -EINVAL; - goto end; + len = ustcomm_recv_unix_sock(sock, chan_data, var_len); + if (len != var_len) { + goto error_recv; } - /* this is our fd */ - for (i = 0; i < sizeof(int); i++) - tmp.vc[i] = CMSG_DATA(cmsg)[i]; - ret = tmp.vi; - /* - * Useful for fd leak debug. - * fprintf(stderr, "received fd %d\n", ret); - */ -end: - if (ret < 0) { - int shutret; + *_chan_data = chan_data; + return len; + +error_recv: + free(chan_data); +error_alloc: +error_check: + return len; +} - shutret = shutdown(sock, SHUT_RDWR); - if (shutret) - fprintf(stderr, "Socket shutdown error"); +int ustcomm_recv_stream_from_sessiond(int sock, + uint64_t *memory_map_size, + int *shm_fd, int *wakeup_fd) +{ + ssize_t len; + int ret; + int fds[2]; + + /* recv shm fd and wakeup fd */ + len = ustcomm_recv_fds_unix_sock(sock, fds, 2); + if (len <= 0) { + if (len < 0) { + ret = len; + goto error; + } else { + ret = -EIO; + goto error; + } } + *shm_fd = fds[0]; + *wakeup_fd = fds[1]; + return 0; + +error: return ret; }