uevent_listen.zip_On Message_uevent

/* * uevent_listen.c - dump netlink uevents from the kernel to stdout * * Only kernels from version 2.6.10* on provide the uevent netlink socket. * Until the libc-kernel-headers are updated, you need to compile with: * * gcc -I /lib/modules/`uname -r`/build/include -o uevent_listen uevent_listen.c * * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation version 2 of the License. * * This program 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 * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <time.h> #include <sys/socket.h> #include <sys/user.h> #include <asm/types.h> #include <linux/netlink.h> /* environment buffer, the kernel's size in lib/kobject_uevent.c should fit in */ #define HOTPLUG_BUFFER_SIZE 1024 #define HOTPLUG_NUM_ENVP 32 #define OBJECT_SIZE 512 int main(int argc, char *argv[]) { int sock; struct sockaddr_nl snl; int retval; if (getuid() != 0) { printf("need to be root, exit\n"); exit(1); } memset(&snl, 0x00, sizeof(struct sockaddr_nl)); snl.nl_family = AF_NETLINK; snl.nl_pid = getpid(); snl.nl_groups = 1; sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT); if (sock == -1) { printf("error getting socket, exit\n"); exit(1); } retval = bind(sock, (struct sockaddr *) &snl, sizeof(struct sockaddr_nl)); if (retval < 0) { printf("bind failed, exit\n"); goto exit; } while (1) { static char buffer[HOTPLUG_BUFFER_SIZE + OBJECT_SIZE]; static char object[OBJECT_SIZE]; const char *devpath; const char *action; const char *envp[HOTPLUG_NUM_ENVP]; int i; char *pos; size_t bufpos; ssize_t buflen; buflen = recv(sock, &buffer, sizeof(buffer), 0); if (buflen < 0) { printf("error receiving message\n"); continue; } if ((size_t)buflen > sizeof(buffer)-1) buflen = sizeof(buffer)-1; buffer[buflen] = '\0'; /* save start of payload */ bufpos = strlen(buffer) + 1; /* action string */ action = buffer; pos = strchr(buffer, '@'); if (!pos) continue; pos[0] = '\0'; /* sysfs path */ devpath = &pos[1]; /* hotplug events have the environment attached - reconstruct envp[] */ for (i = 0; (bufpos < (size_t)buflen) && (i < HOTPLUG_NUM_ENVP-1); i++) { int keylen; char *key; key = &buffer[bufpos]; keylen = strlen(key); envp[i] = key; bufpos += keylen + 1; } envp[i] = NULL; printf("[%i] received '%s' from '%s'\n", time(NULL), action, devpath); /* print payload environment */ for (i = 0; envp[i] != NULL; i++) printf("%s\n", envp[i]); printf("\n"); } exit: close(sock); exit(1); }