/* 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 Denis Vlasenko * * Licensed under GPL version 2, see file LICENSE in this tarball for details. */ #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 *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 *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 *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 *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 * 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 * 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 *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 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 an existing file and return a fd. int xopen(const char *pathname, int flags) { return xopen3(pathname, flags, 0666); } // Warn if we can't open a file and return a fd. int 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 open_or_warn(const char *pathname, int flags) { return open3_or_warn(pathname, flags, 0666); } void xpipe(int filedes[2]) { if (pipe(filedes)) bb_perror_msg_and_die("can't create pipe"); } void xunlink(const char *pathname) { if (unlink(pathname)) bb_perror_msg_and_die("can't remove file '%s'", pathname); } // Turn on nonblocking I/O on a fd int ndelay_on(int fd) { return fcntl(fd, F_SETFL, fcntl(fd,F_GETFL,0) | O_NONBLOCK); } int ndelay_off(int fd) { return fcntl(fd, F_SETFL, fcntl(fd,F_GETFL,0) & ~O_NONBLOCK); } void xdup2(int from, int to) { if (dup2(from, to) != to) bb_perror_msg_and_die("can't duplicate file descriptor"); } // "Renumber" opened fd void 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 xwrite(int fd, const void *buf, size_t count) { if (count) { ssize_t size = full_write(fd, buf, count); if (size != count) bb_error_msg_and_die("short write"); } } // Die with an error message if we can't lseek to the right spot. off_t 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; } // Die with supplied filename if this FILE * has ferror set. void 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 die_if_ferror_stdout(void) { die_if_ferror(stdout, bb_msg_standard_output); } // Die with an error message if we have trouble flushing stdout. void xfflush_stdout(void) { if (fflush(stdout)) { bb_perror_msg_and_die(bb_msg_standard_output); } } void sig_block(int sig) { sigset_t ss; sigemptyset(&ss); sigaddset(&ss, sig); sigprocmask(SIG_BLOCK, &ss, NULL); } void sig_unblock(int sig) { sigset_t ss; sigemptyset(&ss); sigaddset(&ss, sig); sigprocmask(SIG_UNBLOCK, &ss, NULL); } #if 0 void sig_blocknone(void) { sigset_t ss; sigemptyset(&ss); sigprocmask(SIG_SETMASK, &ss, NULL); } #endif void sig_catch(int sig, void (*f)(int)) { struct sigaction sa; sa.sa_handler = f; sa.sa_flags = 0; sigemptyset(&sa.sa_mask); sigaction(sig, &sa, NULL); } void sig_pause(void) { sigset_t ss; sigemptyset(&ss); sigsuspend(&ss); } void xsetenv(const char *key, const char *value) { if (setenv(key, value, 1)) bb_error_msg_and_die(bb_msg_memory_exhausted); } // Converts unsigned long long value into compact 4-char // representation. Examples: "1234", "1.2k", " 27M", "123T" // Fifth char is always '\0' void smart_ulltoa5(unsigned long long ul, char buf[5]) { const char *fmt; char c; unsigned v,idx = 0; ul *= 10; if (ul > 9999*10) { // do not scale if 9999 or less while (ul >= 10000) { ul /= 1024; idx++; } } v = ul; // ullong divisions are expensive, avoid them fmt = " 123456789"; if (!idx) { // 9999 or less: use 1234 format c = buf[0] = " 123456789"[v/10000]; if (c != ' ') fmt = "0123456789"; c = buf[1] = fmt[v/1000%10]; if (c != ' ') fmt = "0123456789"; buf[2] = fmt[v/100%10]; buf[3] = "0123456789"[v/10%10]; } else { if (v >= 10*10) { // scaled value is >=10: use 123M format c = buf[0] = " 123456789"[v/1000]; if (c != ' ') fmt = "0123456789"; buf[1] = fmt[v/100%10]; buf[2] = "0123456789"[v/10%10]; } else { // scaled value is <10: use 1.2M format buf[0] = "0123456789"[v/10]; buf[1] = '.'; buf[2] = "0123456789"[v%10]; } // see http://en.wikipedia.org/wiki/Tera buf[3] = " kMGTPEZY"[idx]; } buf[4] = '\0'; } // Convert unsigned integer to ascii, writing into supplied buffer. // A truncated result contains the first few digits of the result ala strncpy. // Returns a pointer past last generated digit, does _not_ store NUL. void BUG_sizeof_unsigned_not_4(void); char *utoa_to_buf(unsigned n, char *buf, unsigned buflen) { unsigned i, out, res; if (sizeof(unsigned) != 4) BUG_sizeof_unsigned_not_4(); if (buflen) { out = 0; for (i = 1000000000; i; i /= 10) { res = n / i; if (res || out || i == 1) { if (!--buflen) break; out++; n -= res*i; *buf++ = '0' + res; } } } return buf; } // Convert signed integer to ascii, like utoa_to_buf() char *itoa_to_buf(int n, char *buf, unsigned buflen) { if (buflen && n<0) { n = -n; *buf++ = '-'; buflen--; } return utoa_to_buf((unsigned)n, buf, buflen); } // The following two functions use a static buffer, so calling either one a // second time will overwrite previous results. // // The largest 32 bit integer is -2 billion plus null terminator, or 12 bytes. // Int should always be 32 bits on any remotely Unix-like system, see // http://www.unix.org/whitepapers/64bit.html for the reasons why. static char local_buf[12]; // Convert unsigned integer to ascii using a static buffer (returned). char *utoa(unsigned n) { *(utoa_to_buf(n, local_buf, sizeof(local_buf))) = '\0'; return local_buf; } // Convert signed integer to ascii using a static buffer (returned). char *itoa(int n) { *(itoa_to_buf(n, local_buf, sizeof(local_buf))) = '\0'; return local_buf; } // Emit a string of hex representation of bytes char *bin2hex(char *p, const char *cp, int count) { while (count) { unsigned char c = *cp++; /* put lowercase hex digits */ *p++ = 0x20 | bb_hexdigits_upcase[c >> 4]; *p++ = 0x20 | bb_hexdigits_upcase[c & 0xf]; count--; } return p; } // 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 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 xsetuid(uid_t uid) { if (setuid(uid)) bb_perror_msg_and_die("setuid"); } // Return how long the file at fd is, if there's any way to determine it. off_t fdlength(int fd) { off_t bottom = 0, top = 0, pos; long size; // If the ioctl works for this, return it. if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512; // FIXME: explain why lseek(SEEK_END) is not used here! // If not, do a binary search for the last location we can read. (Some // block devices don't do BLKGETSIZE right.) do { char temp; pos = bottom + (top - bottom) / 2; // If we can read from the current location, it's bigger. if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) { if (bottom == top) bottom = top = (top+1) * 2; else bottom = pos; // If we can't, it's smaller. } else { if (bottom == top) { if (!top) return 0; bottom = top/2; } else top = pos; } } while (bottom + 1 != top); return pos + 1; } // Die with an error message if we can't malloc() enough space and do an // sprintf() into that space. char *xasprintf(const char *format, ...) { va_list p; int r; char *string_ptr; #if 1 // GNU extension va_start(p, format); r = vasprintf(&string_ptr, format, p); va_end(p); #else // Bloat for systems that haven't got the GNU extension. va_start(p, format); r = vsnprintf(NULL, 0, format, p); va_end(p); string_ptr = xmalloc(r+1); va_start(p, format); r = vsnprintf(string_ptr, r+1, format, p); va_end(p); #endif if (r < 0) bb_error_msg_and_die(bb_msg_memory_exhausted); return string_ptr; } #if 0 /* If we will ever meet a libc which hasn't [f]dprintf... */ int fdprintf(int fd, const char *format, ...) { va_list p; int r; char *string_ptr; #if 1 // GNU extension va_start(p, format); r = vasprintf(&string_ptr, format, p); va_end(p); #else // Bloat for systems that haven't got the GNU extension. va_start(p, format); r = vsnprintf(NULL, 0, format, p) + 1; va_end(p); string_ptr = malloc(r); if (string_ptr) { va_start(p, format); r = vsnprintf(string_ptr, r, format, p); va_end(p); } #endif if (r >= 0) { full_write(fd, string_ptr, r); free(string_ptr); } return r; } #endif // Die with an error message if we can't copy an entire FILE * to stdout, then // close that file. void xprint_and_close_file(FILE *file) { fflush(stdout); // copyfd outputs error messages for us. if (bb_copyfd_eof(fileno(file), 1) == -1) xfunc_die(); fclose(file); } // Die if we can't chdir to a new path. void xchdir(const char *path) { if (chdir(path)) bb_perror_msg_and_die("chdir(%s)", path); } // Print a warning message if opendir() fails, but don't die. DIR *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 *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 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"; if (domain == AF_PACKET) s = "PACKET"; if (domain == AF_NETLINK) s = "NETLINK"; USE_FEATURE_IPV6(if (domain == AF_INET6) s = "INET6";) bb_perror_msg_and_die("socket(AF_%s)", s); #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 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 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 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 xstat(const char *name, struct stat *stat_buf) { if (stat(name, stat_buf)) bb_perror_msg_and_die("can't stat '%s'", name); } // selinux_or_die() - die if SELinux is disabled. void 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 } /* It is perfectly ok to pass in a NULL for either width or for * height, in which case that value will not be set. */ int get_terminal_width_height(int fd, int *width, int *height) { struct winsize win = { 0, 0, 0, 0 }; int ret = ioctl(fd, TIOCGWINSZ, &win); if (height) { if (!win.ws_row) { char *s = getenv("LINES"); if (s) win.ws_row = atoi(s); } if (win.ws_row <= 1 || win.ws_row >= 30000) win.ws_row = 24; *height = (int) win.ws_row; } if (width) { if (!win.ws_col) { char *s = getenv("COLUMNS"); if (s) win.ws_col = atoi(s); } if (win.ws_col <= 1 || win.ws_col >= 30000) win.ws_col = 80; *width = (int) win.ws_col; } return ret; } void ioctl_or_perror_and_die(int fd, int request, void *argp, const char *fmt,...) { va_list p; if (ioctl(fd, request, argp) < 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(); } } int ioctl_or_perror(int fd, int 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 bb_ioctl_or_warn(int fd, int request, void *argp, const char *ioctl_name) { int ret; ret = ioctl(fd, request, argp); if (ret < 0) bb_perror_msg("%s", ioctl_name); return ret; } void bb_xioctl(int fd, int request, void *argp, const char *ioctl_name) { if (ioctl(fd, request, argp) < 0) bb_perror_msg_and_die("%s", ioctl_name); } #else int bb_ioctl_or_warn(int fd, int request, void *argp) { int ret; ret = ioctl(fd, request, argp); if (ret < 0) bb_perror_msg("ioctl %#x failed", request); return ret; } void bb_xioctl(int fd, int request, void *argp) { if (ioctl(fd, request, argp) < 0) bb_perror_msg_and_die("ioctl %#x failed", request); } #endif