/* vi: set sw=4 ts=4: */ /* * Adapted from ash applet code * * This code is derived from software contributed to Berkeley by * Kenneth Almquist. * * Copyright (c) 1989, 1991, 1993, 1994 * The Regents of the University of California. All rights reserved. * * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au> * was re-ported from NetBSD and debianized. * * Copyright (c) 2010 Denys Vlasenko * Split from ash.c * * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ #include "libbb.h" #include "shell_common.h" #include <sys/resource.h> /* getrlimit */ const char defifsvar[] ALIGN1 = "IFS= \t\n"; int FAST_FUNC is_well_formed_var_name(const char *s, char terminator) { if (!s || !(isalpha(*s) || *s == '_')) return 0; do s++; while (isalnum(*s) || *s == '_'); return *s == terminator; } /* read builtin */ /* Needs to be interruptible: shell must handle traps and shell-special signals * while inside read. To implement this, be sure to not loop on EINTR * and return errno == EINTR reliably. */ //TODO: use more efficient setvar() which takes a pointer to malloced "VAR=VAL" //string. hush naturally has it, and ash has setvareq(). //Here we can simply store "VAR=" at buffer start and store read data directly //after "=", then pass buffer to setvar() to consume. const char* FAST_FUNC shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val), char **argv, const char *ifs, int read_flags, const char *opt_n, const char *opt_p, const char *opt_t, const char *opt_u ) { unsigned err; unsigned end_ms; /* -t TIMEOUT */ int fd; /* -u FD */ int nchars; /* -n NUM */ char **pp; char *buffer; struct termios tty, old_tty; const char *retval; int bufpos; /* need to be able to hold -1 */ int startword; smallint backslash; errno = err = 0; pp = argv; while (*pp) { if (!is_well_formed_var_name(*pp, '\0')) { /* Mimic bash message */ bb_error_msg("read: '%s': not a valid identifier", *pp); return (const char *)(uintptr_t)1; } pp++; } nchars = 0; /* if != 0, -n is in effect */ if (opt_n) { nchars = bb_strtou(opt_n, NULL, 10); if (nchars < 0 || errno) return "invalid count"; /* note: "-n 0": off (bash 3.2 does this too) */ } end_ms = 0; if (opt_t) { end_ms = bb_strtou(opt_t, NULL, 10); if (errno || end_ms > UINT_MAX / 2048) return "invalid timeout"; end_ms *= 1000; #if 0 /* even bash has no -t N.NNN support */ ts.tv_sec = bb_strtou(opt_t, &p, 10); ts.tv_usec = 0; /* EINVAL means number is ok, but not terminated by NUL */ if (*p == '.' && errno == EINVAL) { char *p2; if (*++p) { int scale; ts.tv_usec = bb_strtou(p, &p2, 10); if (errno) return "invalid timeout"; scale = p2 - p; /* normalize to usec */ if (scale > 6) return "invalid timeout"; while (scale++ < 6) ts.tv_usec *= 10; } } else if (ts.tv_sec < 0 || errno) { return "invalid timeout"; } if (!(ts.tv_sec | ts.tv_usec)) { /* both are 0? */ return "invalid timeout"; } #endif /* if 0 */ } fd = STDIN_FILENO; if (opt_u) { fd = bb_strtou(opt_u, NULL, 10); if (fd < 0 || errno) return "invalid file descriptor"; } if (opt_p && isatty(fd)) { fputs(opt_p, stderr); fflush_all(); } if (ifs == NULL) ifs = defifs; if (nchars || (read_flags & BUILTIN_READ_SILENT)) { tcgetattr(fd, &tty); old_tty = tty; if (nchars) { tty.c_lflag &= ~ICANON; // Setting it to more than 1 breaks poll(): // it blocks even if there's data. !?? //tty.c_cc[VMIN] = nchars < 256 ? nchars : 255; /* reads would block only if < 1 char is available */ tty.c_cc[VMIN] = 1; /* no timeout (reads block forever) */ tty.c_cc[VTIME] = 0; } if (read_flags & BUILTIN_READ_SILENT) { tty.c_lflag &= ~(ECHO | ECHOK | ECHONL); } /* This forces execution of "restoring" tcgetattr later */ read_flags |= BUILTIN_READ_SILENT; /* if tcgetattr failed, tcsetattr will fail too. * Ignoring, it's harmless. */ tcsetattr(fd, TCSANOW, &tty); } retval = (const char *)(uintptr_t)0; startword = 1; backslash = 0; if (end_ms) /* NB: end_ms stays nonzero: */ end_ms = ((unsigned)monotonic_ms() + end_ms) | 1; buffer = NULL; bufpos = 0; do { char c; struct pollfd pfd[1]; int timeout; if ((bufpos & 0xff) == 0) buffer = xrealloc(buffer, bufpos + 0x101); timeout = -1; if (end_ms) { timeout = end_ms - (unsigned)monotonic_ms(); if (timeout <= 0) { /* already late? */ retval = (const char *)(uintptr_t)1; goto ret; } } /* We must poll even if timeout is -1: * we want to be interrupted if signal arrives, * regardless of SA_RESTART-ness of that signal! */ errno = 0; pfd[0].fd = fd; pfd[0].events = POLLIN; if (poll(pfd, 1, timeout) != 1) { /* timed out, or EINTR */ err = errno; retval = (const char *)(uintptr_t)1; goto ret; } if (read(fd, &buffer[bufpos], 1) != 1) { err = errno; retval = (const char *)(uintptr_t)1; break; } c = buffer[bufpos]; if (c == '\0') continue; if (backslash) { backslash = 0; if (c != '\n') goto put; continue; } if (!(read_flags & BUILTIN_READ_RAW) && c == '\\') { backslash = 1; continue; } if (c == '\n') break; /* $IFS splitting. NOT done if we run "read" * without variable names (bash compat). * Thus, "read" and "read REPLY" are not the same. */ if (argv[0]) { /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05 */ const char *is_ifs = strchr(ifs, c); if (startword && is_ifs) { if (isspace(c)) continue; /* it is a non-space ifs char */ startword--; if (startword == 1) /* first one? */ continue; /* yes, it is not next word yet */ } startword = 0; if (argv[1] != NULL && is_ifs) { buffer[bufpos] = '\0'; bufpos = 0; setvar(*argv, buffer); argv++; /* can we skip one non-space ifs char? (2: yes) */ startword = isspace(c) ? 2 : 1; continue; } } put: bufpos++; } while (--nchars); if (argv[0]) { /* Remove trailing space $IFS chars */ while (--bufpos >= 0 && isspace(buffer[bufpos]) && strchr(ifs, buffer[bufpos]) != NULL) continue; buffer[bufpos + 1] = '\0'; /* Use the remainder as a value for the next variable */ setvar(*argv, buffer); /* Set the rest to "" */ while (*++argv) setvar(*argv, ""); } else { /* Note: no $IFS removal */ buffer[bufpos] = '\0'; setvar("REPLY", buffer); } ret: free(buffer); if (read_flags & BUILTIN_READ_SILENT) tcsetattr(fd, TCSANOW, &old_tty); errno = err; return retval; } /* ulimit builtin */ struct limits { uint8_t cmd; /* RLIMIT_xxx fit into it */ uint8_t factor_shift; /* shift by to get rlim_{cur,max} values */ char option; const char *name; }; static const struct limits limits_tbl[] = { #ifdef RLIMIT_FSIZE { RLIMIT_FSIZE, 9, 'f', "file size (blocks)" }, #endif #ifdef RLIMIT_CPU { RLIMIT_CPU, 0, 't', "cpu time (seconds)" }, #endif #ifdef RLIMIT_DATA { RLIMIT_DATA, 10, 'd', "data seg size (kb)" }, #endif #ifdef RLIMIT_STACK { RLIMIT_STACK, 10, 's', "stack size (kb)" }, #endif #ifdef RLIMIT_CORE { RLIMIT_CORE, 9, 'c', "core file size (blocks)" }, #endif #ifdef RLIMIT_RSS { RLIMIT_RSS, 10, 'm', "resident set size (kb)" }, #endif #ifdef RLIMIT_MEMLOCK { RLIMIT_MEMLOCK, 10, 'l', "locked memory (kb)" }, #endif #ifdef RLIMIT_NPROC { RLIMIT_NPROC, 0, 'p', "processes" }, #endif #ifdef RLIMIT_NOFILE { RLIMIT_NOFILE, 0, 'n', "file descriptors" }, #endif #ifdef RLIMIT_AS { RLIMIT_AS, 10, 'v', "address space (kb)" }, #endif #ifdef RLIMIT_LOCKS { RLIMIT_LOCKS, 0, 'w', "locks" }, #endif #ifdef RLIMIT_NICE { RLIMIT_NICE, 0, 'e', "scheduling priority" }, #endif #ifdef RLIMIT_RTPRIO { RLIMIT_RTPRIO, 0, 'r', "real-time priority" }, #endif }; enum { OPT_hard = (1 << 0), OPT_soft = (1 << 1), }; /* "-": treat args as parameters of option with ASCII code 1 */ static const char ulimit_opt_string[] = "-HSa" #ifdef RLIMIT_FSIZE "f::" #endif #ifdef RLIMIT_CPU "t::" #endif #ifdef RLIMIT_DATA "d::" #endif #ifdef RLIMIT_STACK "s::" #endif #ifdef RLIMIT_CORE "c::" #endif #ifdef RLIMIT_RSS "m::" #endif #ifdef RLIMIT_MEMLOCK "l::" #endif #ifdef RLIMIT_NPROC "p::" #endif #ifdef RLIMIT_NOFILE "n::" #endif #ifdef RLIMIT_AS "v::" #endif #ifdef RLIMIT_LOCKS "w::" #endif #ifdef RLIMIT_NICE "e::" #endif #ifdef RLIMIT_RTPRIO "r::" #endif ; static void printlim(unsigned opts, const struct rlimit *limit, const struct limits *l) { rlim_t val; val = limit->rlim_max; if (!(opts & OPT_hard)) val = limit->rlim_cur; if (val == RLIM_INFINITY) printf("unlimited\n"); else { val >>= l->factor_shift; printf("%llu\n", (long long) val); } } int FAST_FUNC shell_builtin_ulimit(char **argv) { unsigned opts; unsigned argc; /* We can't use getopt32: need to handle commands like * ulimit 123 -c2 -l 456 */ /* In case getopt was already called: * reset the libc getopt() function, which keeps internal state. */ #ifdef __GLIBC__ optind = 0; #else /* BSD style */ optind = 1; /* optreset = 1; */ #endif /* optarg = NULL; opterr = 0; optopt = 0; - do we need this?? */ argc = 1; while (argv[argc]) argc++; opts = 0; while (1) { struct rlimit limit; const struct limits *l; int opt_char = getopt(argc, argv, ulimit_opt_string); if (opt_char == -1) break; if (opt_char == 'H') { opts |= OPT_hard; continue; } if (opt_char == 'S') { opts |= OPT_soft; continue; } if (opt_char == 'a') { for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) { getrlimit(l->cmd, &limit); printf("-%c: %-30s ", l->option, l->name); printlim(opts, &limit, l); } continue; } if (opt_char == 1) opt_char = 'f'; for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) { if (opt_char == l->option) { char *val_str; getrlimit(l->cmd, &limit); val_str = optarg; if (!val_str && argv[optind] && argv[optind][0] != '-') val_str = argv[optind++]; /* ++ skips NN in "-c NN" case */ if (val_str) { rlim_t val; if (strcmp(val_str, "unlimited") == 0) val = RLIM_INFINITY; else { if (sizeof(val) == sizeof(int)) val = bb_strtou(val_str, NULL, 10); else if (sizeof(val) == sizeof(long)) val = bb_strtoul(val_str, NULL, 10); else val = bb_strtoull(val_str, NULL, 10); if (errno) { bb_error_msg("invalid number '%s'", val_str); return EXIT_FAILURE; } val <<= l->factor_shift; } //bb_error_msg("opt %c val_str:'%s' val:%lld", opt_char, val_str, (long long)val); /* from man bash: "If neither -H nor -S * is specified, both the soft and hard * limits are set. */ if (!opts) opts = OPT_hard + OPT_soft; if (opts & OPT_hard) limit.rlim_max = val; if (opts & OPT_soft) limit.rlim_cur = val; //bb_error_msg("setrlimit(%d, %lld, %lld)", l->cmd, (long long)limit.rlim_cur, (long long)limit.rlim_max); if (setrlimit(l->cmd, &limit) < 0) { bb_perror_msg("error setting limit"); return EXIT_FAILURE; } } else { printlim(opts, &limit, l); } break; } } /* for (every possible opt) */ if (l == &limits_tbl[ARRAY_SIZE(limits_tbl)]) { /* bad option. getopt already complained. */ break; } } /* while (there are options) */ return 0; }