/* vi: set sw=4 ts=4: */ /* * Utility routines. * * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> * Copyright (C) 2006 Rob Landley * Copyright (C) 2006 Denys Vlasenko * * Licensed under GPLv2, see file LICENSE in this source tree. */ /* We need to have separate xfuncs.c and xfuncs_printf.c because * with current linkers, even with section garbage collection, * if *.o module references any of XXXprintf functions, you pull in * entire printf machinery. Even if you do not use the function * which uses XXXprintf. * * xfuncs.c contains functions (not necessarily xfuncs) * which do not pull in printf, directly or indirectly. * xfunc_printf.c contains those which do. */ #include "libbb.h" /* All the functions starting with "x" call bb_error_msg_and_die() if they * fail, so callers never need to check for errors. If it returned, it * succeeded. */ #ifndef DMALLOC /* dmalloc provides variants of these that do abort() on failure. * Since dmalloc's prototypes overwrite the impls here as they are * included after these prototypes in libbb.h, all is well. */ // Warn if we can't allocate size bytes of memory. void* FAST_FUNC malloc_or_warn(size_t size) { void *ptr = malloc(size); if (ptr == NULL && size != 0) bb_error_msg(bb_msg_memory_exhausted); return ptr; } // Die if we can't allocate size bytes of memory. void* FAST_FUNC xmalloc(size_t size) { void *ptr = malloc(size); if (ptr == NULL && size != 0) bb_error_msg_and_die(bb_msg_memory_exhausted); return ptr; } // Die if we can't resize previously allocated memory. (This returns a pointer // to the new memory, which may or may not be the same as the old memory. // It'll copy the contents to a new chunk and free the old one if necessary.) void* FAST_FUNC xrealloc(void *ptr, size_t size) { ptr = realloc(ptr, size); if (ptr == NULL && size != 0) bb_error_msg_and_die(bb_msg_memory_exhausted); return ptr; } #endif /* DMALLOC */ // Die if we can't allocate and zero size bytes of memory. void* FAST_FUNC xzalloc(size_t size) { void *ptr = xmalloc(size); memset(ptr, 0, size); return ptr; } // Die if we can't copy a string to freshly allocated memory. char* FAST_FUNC xstrdup(const char *s) { char *t; if (s == NULL) return NULL; t = strdup(s); if (t == NULL) bb_error_msg_and_die(bb_msg_memory_exhausted); return t; } // Die if we can't allocate n+1 bytes (space for the null terminator) and copy // the (possibly truncated to length n) string into it. char* FAST_FUNC xstrndup(const char *s, int n) { int m; char *t; if (ENABLE_DEBUG && s == NULL) bb_error_msg_and_die("xstrndup bug"); /* We can just xmalloc(n+1) and strncpy into it, */ /* but think about xstrndup("abc", 10000) wastage! */ m = n; t = (char*) s; while (m) { if (!*t) break; m--; t++; } n -= m; t = xmalloc(n + 1); t[n] = '\0'; return memcpy(t, s, n); } // Die if we can't open a file and return a FILE* to it. // Notice we haven't got xfread(), This is for use with fscanf() and friends. FILE* FAST_FUNC xfopen(const char *path, const char *mode) { FILE *fp = fopen(path, mode); if (fp == NULL) bb_perror_msg_and_die("can't open '%s'", path); return fp; } // Die if we can't open a file and return a fd. int FAST_FUNC xopen3(const char *pathname, int flags, int mode) { int ret; ret = open(pathname, flags, mode); if (ret < 0) { bb_perror_msg_and_die("can't open '%s'", pathname); } return ret; } // Die if we can't open a file and return a fd. int FAST_FUNC xopen(const char *pathname, int flags) { return xopen3(pathname, flags, 0666); } /* Die if we can't open an existing file readonly with O_NONBLOCK * and return the fd. * Note that for ioctl O_RDONLY is sufficient. */ int FAST_FUNC xopen_nonblocking(const char *pathname) { return xopen(pathname, O_RDONLY | O_NONBLOCK); } // Warn if we can't open a file and return a fd. int FAST_FUNC open3_or_warn(const char *pathname, int flags, int mode) { int ret; ret = open(pathname, flags, mode); if (ret < 0) { bb_perror_msg("can't open '%s'", pathname); } return ret; } // Warn if we can't open a file and return a fd. int FAST_FUNC open_or_warn(const char *pathname, int flags) { return open3_or_warn(pathname, flags, 0666); } void FAST_FUNC xunlink(const char *pathname) { if (unlink(pathname)) bb_perror_msg_and_die("can't remove file '%s'", pathname); } void FAST_FUNC xrename(const char *oldpath, const char *newpath) { if (rename(oldpath, newpath)) bb_perror_msg_and_die("can't move '%s' to '%s'", oldpath, newpath); } int FAST_FUNC rename_or_warn(const char *oldpath, const char *newpath) { int n = rename(oldpath, newpath); if (n) bb_perror_msg("can't move '%s' to '%s'", oldpath, newpath); return n; } void FAST_FUNC xpipe(int filedes[2]) { if (pipe(filedes)) bb_perror_msg_and_die("can't create pipe"); } void FAST_FUNC xdup2(int from, int to) { if (dup2(from, to) != to) bb_perror_msg_and_die("can't duplicate file descriptor"); } // "Renumber" opened fd void FAST_FUNC xmove_fd(int from, int to) { if (from == to) return; xdup2(from, to); close(from); } // Die with an error message if we can't write the entire buffer. void FAST_FUNC xwrite(int fd, const void *buf, size_t count) { if (count) { ssize_t size = full_write(fd, buf, count); if ((size_t)size != count) bb_error_msg_and_die("short write"); } } void FAST_FUNC xwrite_str(int fd, const char *str) { xwrite(fd, str, strlen(str)); } void FAST_FUNC xclose(int fd) { if (close(fd)) bb_perror_msg_and_die("close failed"); } // Die with an error message if we can't lseek to the right spot. off_t FAST_FUNC xlseek(int fd, off_t offset, int whence) { off_t off = lseek(fd, offset, whence); if (off == (off_t)-1) { if (whence == SEEK_SET) bb_perror_msg_and_die("lseek(%"OFF_FMT"u)", offset); bb_perror_msg_and_die("lseek"); } return off; } int FAST_FUNC xmkstemp(char *template) { int fd = mkstemp(template); if (fd < 0) bb_perror_msg_and_die("can't create temp file '%s'", template); return fd; } // Die with supplied filename if this FILE* has ferror set. void FAST_FUNC die_if_ferror(FILE *fp, const char *fn) { if (ferror(fp)) { /* ferror doesn't set useful errno */ bb_error_msg_and_die("%s: I/O error", fn); } } // Die with an error message if stdout has ferror set. void FAST_FUNC die_if_ferror_stdout(void) { die_if_ferror(stdout, bb_msg_standard_output); } int FAST_FUNC fflush_all(void) { return fflush(NULL); } int FAST_FUNC bb_putchar(int ch) { return putchar(ch); } /* Die with an error message if we can't copy an entire FILE* to stdout, * then close that file. */ void FAST_FUNC xprint_and_close_file(FILE *file) { fflush_all(); // copyfd outputs error messages for us. if (bb_copyfd_eof(fileno(file), STDOUT_FILENO) == -1) xfunc_die(); fclose(file); } // Die with an error message if we can't malloc() enough space and do an // sprintf() into that space. char* FAST_FUNC xasprintf(const char *format, ...) { va_list p; int r; char *string_ptr; va_start(p, format); r = vasprintf(&string_ptr, format, p); va_end(p); if (r < 0) bb_error_msg_and_die(bb_msg_memory_exhausted); return string_ptr; } void FAST_FUNC xsetenv(const char *key, const char *value) { if (setenv(key, value, 1)) bb_error_msg_and_die(bb_msg_memory_exhausted); } /* Handles "VAR=VAL" strings, even those which are part of environ * _right now_ */ void FAST_FUNC bb_unsetenv(const char *var) { char *tp = strchr(var, '='); if (!tp) { unsetenv(var); return; } /* In case var was putenv'ed, we can't replace '=' * with NUL and unsetenv(var) - it won't work, * env is modified by the replacement, unsetenv * sees "VAR" instead of "VAR=VAL" and does not remove it! * horror :( */ tp = xstrndup(var, tp - var); unsetenv(tp); free(tp); } void FAST_FUNC bb_unsetenv_and_free(char *var) { bb_unsetenv(var); free(var); } // Die with an error message if we can't set gid. (Because resource limits may // limit this user to a given number of processes, and if that fills up the // setgid() will fail and we'll _still_be_root_, which is bad.) void FAST_FUNC xsetgid(gid_t gid) { if (setgid(gid)) bb_perror_msg_and_die("setgid"); } // Die with an error message if we can't set uid. (See xsetgid() for why.) void FAST_FUNC xsetuid(uid_t uid) { if (setuid(uid)) bb_perror_msg_and_die("setuid"); } // Die if we can't chdir to a new path. void FAST_FUNC xchdir(const char *path) { if (chdir(path)) bb_perror_msg_and_die("chdir(%s)", path); } void FAST_FUNC xchroot(const char *path) { if (chroot(path)) bb_perror_msg_and_die("can't change root directory to %s", path); } // Print a warning message if opendir() fails, but don't die. DIR* FAST_FUNC warn_opendir(const char *path) { DIR *dp; dp = opendir(path); if (!dp) bb_perror_msg("can't open '%s'", path); return dp; } // Die with an error message if opendir() fails. DIR* FAST_FUNC xopendir(const char *path) { DIR *dp; dp = opendir(path); if (!dp) bb_perror_msg_and_die("can't open '%s'", path); return dp; } // Die with an error message if we can't open a new socket. int FAST_FUNC xsocket(int domain, int type, int protocol) { int r = socket(domain, type, protocol); if (r < 0) { /* Hijack vaguely related config option */ #if ENABLE_VERBOSE_RESOLUTION_ERRORS const char *s = "INET"; # ifdef AF_PACKET if (domain == AF_PACKET) s = "PACKET"; # endif # ifdef AF_NETLINK if (domain == AF_NETLINK) s = "NETLINK"; # endif IF_FEATURE_IPV6(if (domain == AF_INET6) s = "INET6";) bb_perror_msg_and_die("socket(AF_%s,%d,%d)", s, type, protocol); #else bb_perror_msg_and_die("socket"); #endif } return r; } // Die with an error message if we can't bind a socket to an address. void FAST_FUNC xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen) { if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind"); } // Die with an error message if we can't listen for connections on a socket. void FAST_FUNC xlisten(int s, int backlog) { if (listen(s, backlog)) bb_perror_msg_and_die("listen"); } /* Die with an error message if sendto failed. * Return bytes sent otherwise */ ssize_t FAST_FUNC xsendto(int s, const void *buf, size_t len, const struct sockaddr *to, socklen_t tolen) { ssize_t ret = sendto(s, buf, len, 0, to, tolen); if (ret < 0) { if (ENABLE_FEATURE_CLEAN_UP) close(s); bb_perror_msg_and_die("sendto"); } return ret; } // xstat() - a stat() which dies on failure with meaningful error message void FAST_FUNC xstat(const char *name, struct stat *stat_buf) { if (stat(name, stat_buf)) bb_perror_msg_and_die("can't stat '%s'", name); } void FAST_FUNC xfstat(int fd, struct stat *stat_buf, const char *errmsg) { /* errmsg is usually a file name, but not always: * xfstat may be called in a spot where file name is no longer * available, and caller may give e.g. "can't stat input file" string. */ if (fstat(fd, stat_buf)) bb_simple_perror_msg_and_die(errmsg); } // selinux_or_die() - die if SELinux is disabled. void FAST_FUNC selinux_or_die(void) { #if ENABLE_SELINUX int rc = is_selinux_enabled(); if (rc == 0) { bb_error_msg_and_die("SELinux is disabled"); } else if (rc < 0) { bb_error_msg_and_die("is_selinux_enabled() failed"); } #else bb_error_msg_and_die("SELinux support is disabled"); #endif } int FAST_FUNC ioctl_or_perror_and_die(int fd, unsigned request, void *argp, const char *fmt,...) { int ret; va_list p; ret = ioctl(fd, request, argp); if (ret < 0) { va_start(p, fmt); bb_verror_msg(fmt, p, strerror(errno)); /* xfunc_die can actually longjmp, so be nice */ va_end(p); xfunc_die(); } return ret; } int FAST_FUNC ioctl_or_perror(int fd, unsigned request, void *argp, const char *fmt,...) { va_list p; int ret = ioctl(fd, request, argp); if (ret < 0) { va_start(p, fmt); bb_verror_msg(fmt, p, strerror(errno)); va_end(p); } return ret; } #if ENABLE_IOCTL_HEX2STR_ERROR int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void *argp, const char *ioctl_name) { int ret; ret = ioctl(fd, request, argp); if (ret < 0) bb_simple_perror_msg(ioctl_name); return ret; } int FAST_FUNC bb_xioctl(int fd, unsigned request, void *argp, const char *ioctl_name) { int ret; ret = ioctl(fd, request, argp); if (ret < 0) bb_simple_perror_msg_and_die(ioctl_name); return ret; } #else int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void *argp) { int ret; ret = ioctl(fd, request, argp); if (ret < 0) bb_perror_msg("ioctl %#x failed", request); return ret; } int FAST_FUNC bb_xioctl(int fd, unsigned request, void *argp) { int ret; ret = ioctl(fd, request, argp); if (ret < 0) bb_perror_msg_and_die("ioctl %#x failed", request); return ret; } #endif char* FAST_FUNC xmalloc_ttyname(int fd) { char *buf = xzalloc(128); int r = ttyname_r(fd, buf, 127); if (r) { free(buf); buf = NULL; } return buf; } void FAST_FUNC generate_uuid(uint8_t *buf) { /* http://www.ietf.org/rfc/rfc4122.txt * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | time_low | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | time_mid | time_hi_and_version | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * |clk_seq_and_variant | node (0-1) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | node (2-5) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * IOW, uuid has this layout: * uint32_t time_low (big endian) * uint16_t time_mid (big endian) * uint16_t time_hi_and_version (big endian) * version is a 4-bit field: * 1 Time-based * 2 DCE Security, with embedded POSIX UIDs * 3 Name-based (MD5) * 4 Randomly generated * 5 Name-based (SHA-1) * uint16_t clk_seq_and_variant (big endian) * variant is a 3-bit field: * 0xx Reserved, NCS backward compatibility * 10x The variant specified in rfc4122 * 110 Reserved, Microsoft backward compatibility * 111 Reserved for future definition * uint8_t node[6] * * For version 4, these bits are set/cleared: * time_hi_and_version & 0x0fff | 0x4000 * clk_seq_and_variant & 0x3fff | 0x8000 */ pid_t pid; int i; i = open("/dev/urandom", O_RDONLY); if (i >= 0) { read(i, buf, 16); close(i); } /* Paranoia. /dev/urandom may be missing. * rand() is guaranteed to generate at least [0, 2^15) range, * but lowest bits in some libc are not so "random". */ srand(monotonic_us()); /* pulls in printf */ pid = getpid(); while (1) { for (i = 0; i < 16; i++) buf[i] ^= rand() >> 5; if (pid == 0) break; srand(pid); pid = 0; } /* version = 4 */ buf[4 + 2 ] = (buf[4 + 2 ] & 0x0f) | 0x40; /* variant = 10x */ buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) | 0x80; } #if BB_MMU pid_t FAST_FUNC xfork(void) { pid_t pid; pid = fork(); if (pid < 0) /* wtf? */ bb_perror_msg_and_die("vfork"+1); return pid; } #endif