X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=2b91ef8a8f9b203f71304c26bc50b420f5a52274;hp=481c17245ddc1978cf4f52fb80fd6261a0484f3e;hb=2d5bdf5bc0e4714d42e5999a4e37553a6bf83575;hpb=3fd11280e82f590eaeda1e3945dafadf82cd8727 diff --git a/src/shared/util.c b/src/shared/util.c index 481c17245..2b91ef8a8 100644 --- a/src/shared/util.c +++ b/src/shared/util.c @@ -61,6 +61,10 @@ #include #undef basename +#ifdef HAVE_SYS_AUXV_H +#include +#endif + #include "macro.h" #include "util.h" #include "ioprio.h" @@ -355,8 +359,23 @@ int safe_atod(const char *s, double *ret_d) { return 0; } +static size_t strcspn_escaped(const char *s, const char *reject) { + bool escaped = false; + size_t n; + + for (n=0; s[n]; n++) { + if (escaped) + escaped = false; + else if (s[n] == '\\') + escaped = true; + else if (strchr(reject, s[n])) + return n; + } + return n; +} + /* Split a string into words. */ -char *split(const char *c, size_t *l, const char *separator, char **state) { +char *split(const char *c, size_t *l, const char *separator, bool quoted, char **state) { char *current; current = *state ? *state : (char*) c; @@ -365,70 +384,19 @@ char *split(const char *c, size_t *l, const char *separator, char **state) { return NULL; current += strspn(current, separator); - *l = strcspn(current, separator); - *state = current+*l; - - return (char*) current; -} - -/* Split a string into words, but consider strings enclosed in '' and - * "" as words even if they include spaces. */ -char *split_quoted(const char *c, size_t *l, char **state) { - const char *current, *e; - bool escaped = false; - - assert(c); - assert(l); - assert(state); - - current = *state ? *state : c; - - current += strspn(current, WHITESPACE); - - if (*current == 0) + if (!*current) return NULL; - else if (*current == '\'') { - current ++; - - for (e = current; *e; e++) { - if (escaped) - escaped = false; - else if (*e == '\\') - escaped = true; - else if (*e == '\'') - break; - } - - *l = e-current; - *state = (char*) (*e == 0 ? e : e+1); - - } else if (*current == '\"') { - current ++; - - for (e = current; *e; e++) { - if (escaped) - escaped = false; - else if (*e == '\\') - escaped = true; - else if (*e == '\"') - break; - } - - *l = e-current; - *state = (char*) (*e == 0 ? e : e+1); - + if (quoted && strchr("\'\"", *current)) { + char quotechar = *(current++); + *l = strcspn_escaped(current, (char[]){quotechar, '\0'}); + *state = current+*l+1; + } else if (quoted) { + *l = strcspn_escaped(current, separator); + *state = current+*l; } else { - for (e = current; *e; e++) { - if (escaped) - escaped = false; - else if (*e == '\\') - escaped = true; - else if (strchr(WHITESPACE, *e)) - break; - } - *l = e-current; - *state = (char*) e; + *l = strcspn(current, separator); + *state = current+*l; } return (char*) current; @@ -436,8 +404,7 @@ char *split_quoted(const char *c, size_t *l, char **state) { int get_parent_of_pid(pid_t pid, pid_t *_ppid) { int r; - _cleanup_fclose_ FILE *f = NULL; - char line[LINE_MAX]; + _cleanup_free_ char *line = NULL; long unsigned ppid; const char *p; @@ -450,14 +417,9 @@ int get_parent_of_pid(pid_t pid, pid_t *_ppid) { } p = procfs_file_alloca(pid, "stat"); - f = fopen(p, "re"); - if (!f) - return -errno; - - if (!fgets(line, sizeof(line), f)) { - r = feof(f) ? -EIO : -errno; + r = read_one_line_file(p, &line); + if (r < 0) return r; - } /* Let's skip the pid and comm fields. The latter is enclosed * in () but does not escape any () in its value, so let's @@ -484,28 +446,17 @@ int get_parent_of_pid(pid_t pid, pid_t *_ppid) { } int get_starttime_of_pid(pid_t pid, unsigned long long *st) { - _cleanup_fclose_ FILE *f = NULL; - char line[LINE_MAX]; + int r; + _cleanup_free_ char *line = NULL; const char *p; assert(pid >= 0); assert(st); - if (pid == 0) - p = "/proc/self/stat"; - else - p = procfs_file_alloca(pid, "stat"); - - f = fopen(p, "re"); - if (!f) - return errno == ENOENT ? -ESRCH : -errno; - - if (!fgets(line, sizeof(line), f)) { - if (ferror(f)) - return -errno; - - return -EIO; - } + p = procfs_file_alloca(pid, "stat"); + r = read_one_line_file(p, &line); + if (r < 0) + return r; /* Let's skip the pid and comm fields. The latter is enclosed * in () but does not escape any () in its value, so let's @@ -569,10 +520,7 @@ int get_process_comm(pid_t pid, char **name) { assert(name); assert(pid >= 0); - if (pid == 0) - p = "/proc/self/comm"; - else - p = procfs_file_alloca(pid, "comm"); + p = procfs_file_alloca(pid, "comm"); r = read_one_line_file(p, name); if (r == -ENOENT) @@ -590,10 +538,7 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * assert(line); assert(pid >= 0); - if (pid == 0) - p = "/proc/self/cmdline"; - else - p = procfs_file_alloca(pid, "cmdline"); + p = procfs_file_alloca(pid, "cmdline"); f = fopen(p, "re"); if (!f) @@ -712,10 +657,7 @@ int get_process_capeff(pid_t pid, char **capeff) { assert(capeff); assert(pid >= 0); - if (pid == 0) - p = "/proc/self/status"; - else - p = procfs_file_alloca(pid, "status"); + p = procfs_file_alloca(pid, "status"); return get_status_field(p, "\nCapEff:", capeff); } @@ -728,10 +670,7 @@ int get_process_exe(pid_t pid, char **name) { assert(pid >= 0); assert(name); - if (pid == 0) - p = "/proc/self/exe"; - else - p = procfs_file_alloca(pid, "exe"); + p = procfs_file_alloca(pid, "exe"); r = readlink_malloc(p, name); if (r < 0) @@ -2098,45 +2037,31 @@ int close_pipe(int p[]) { } ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) { - uint8_t *p; + uint8_t *p = buf; ssize_t n = 0; assert(fd >= 0); assert(buf); - p = buf; - while (nbytes > 0) { ssize_t k; - if ((k = read(fd, p, nbytes)) <= 0) { - - if (k < 0 && errno == EINTR) - continue; - - if (k < 0 && errno == EAGAIN && do_poll) { - struct pollfd pollfd = { - .fd = fd, - .events = POLLIN, - }; + k = read(fd, p, nbytes); + if (k < 0 && errno == EINTR) + continue; - if (poll(&pollfd, 1, -1) < 0) { - if (errno == EINTR) - continue; + if (k < 0 && errno == EAGAIN && do_poll) { - return n > 0 ? n : -errno; - } + /* We knowingly ignore any return value here, + * and expect that any error/EOF is reported + * via read() */ - /* We knowingly ignore the revents value here, - * and expect that any error/EOF is reported - * via read()/write() - */ - - continue; - } + fd_wait_for_event(fd, POLLIN, (usec_t) -1); + continue; + } + if (k <= 0) return n > 0 ? n : (k < 0 ? -errno : 0); - } p += k; nbytes -= k; @@ -2147,46 +2072,31 @@ ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) { } ssize_t loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) { - const uint8_t *p; + const uint8_t *p = buf; ssize_t n = 0; assert(fd >= 0); assert(buf); - p = buf; - while (nbytes > 0) { ssize_t k; k = write(fd, p, nbytes); - if (k <= 0) { - - if (k < 0 && errno == EINTR) - continue; - - if (k < 0 && errno == EAGAIN && do_poll) { - struct pollfd pollfd = { - .fd = fd, - .events = POLLOUT, - }; - - if (poll(&pollfd, 1, -1) < 0) { - if (errno == EINTR) - continue; + if (k < 0 && errno == EINTR) + continue; - return n > 0 ? n : -errno; - } + if (k < 0 && errno == EAGAIN && do_poll) { - /* We knowingly ignore the revents value here, - * and expect that any error/EOF is reported - * via read()/write() - */ + /* We knowingly ignore any return value here, + * and expect that any error/EOF is reported + * via write() */ - continue; - } + fd_wait_for_event(fd, POLLOUT, (usec_t) -1); + continue; + } + if (k <= 0) return n > 0 ? n : (k < 0 ? -errno : 0); - } p += k; nbytes -= k; @@ -2345,42 +2255,60 @@ char* dirname_malloc(const char *path) { return dir; } -unsigned long long random_ull(void) { +int dev_urandom(void *p, size_t n) { _cleanup_close_ int fd; - uint64_t ull; - ssize_t r; + ssize_t k; fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY); if (fd < 0) - goto fallback; - - r = loop_read(fd, &ull, sizeof(ull), true); - if (r != sizeof(ull)) - goto fallback; + return errno == ENOENT ? -ENOSYS : -errno; - return ull; + k = loop_read(fd, p, n, true); + if (k < 0) + return (int) k; + if ((size_t) k != n) + return -EIO; -fallback: - return random() * RAND_MAX + random(); + return 0; } -unsigned random_u(void) { - _cleanup_close_ int fd; - unsigned u; - ssize_t r; +void random_bytes(void *p, size_t n) { + static bool srand_called = false; + uint8_t *q; + int r; - fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY); - if (fd < 0) - goto fallback; + r = dev_urandom(p, n); + if (r >= 0) + return; + + /* If some idiot made /dev/urandom unavailable to us, he'll + * get a PRNG instead. */ - r = loop_read(fd, &u, sizeof(u), true); - if (r != sizeof(u)) - goto fallback; + if (!srand_called) { + unsigned x = 0; - return u; +#ifdef HAVE_SYS_AUXV_H + /* The kernel provides us with a bit of entropy in + * auxv, so let's try to make use of that to seed the + * pseudo-random generator. It's better than + * nothing... */ -fallback: - return random() * RAND_MAX + random(); + void *auxv; + + auxv = (void*) getauxval(AT_RANDOM); + if (auxv) + x ^= *(unsigned*) auxv; +#endif + + x ^= (unsigned) now(CLOCK_REALTIME); + x ^= (unsigned) gettid(); + + srand(x); + srand_called = true; + } + + for (q = p; q < (uint8_t*) p + n; q ++) + *q = rand(); } void rename_process(const char name[8]) { @@ -2532,24 +2460,17 @@ int getttyname_harder(int fd, char **r) { } int get_ctty_devnr(pid_t pid, dev_t *d) { - _cleanup_fclose_ FILE *f = NULL; - char line[LINE_MAX], *p; + int r; + _cleanup_free_ char *line = NULL; + const char *p; unsigned long ttynr; - const char *fn; assert(pid >= 0); - if (pid == 0) - fn = "/proc/self/stat"; - else - fn = procfs_file_alloca(pid, "stat"); - - f = fopen(fn, "re"); - if (!f) - return -errno; - - if (!fgets(line, sizeof(line), f)) - return feof(f) ? -EIO : -errno; + p = procfs_file_alloca(pid, "stat"); + r = read_one_line_file(p, &line); + if (r < 0) + return r; p = strrchr(line, ')'); if (!p) @@ -3914,12 +3835,13 @@ char* hostname_cleanup(char *s, bool lowercase) { } int pipe_eof(int fd) { - int r; struct pollfd pollfd = { .fd = fd, .events = POLLIN|POLLHUP, }; + int r; + r = poll(&pollfd, 1, 0); if (r < 0) return -errno; @@ -3931,13 +3853,16 @@ int pipe_eof(int fd) { } int fd_wait_for_event(int fd, int event, usec_t t) { - int r; + struct pollfd pollfd = { .fd = fd, .events = event, }; - r = poll(&pollfd, 1, t == (usec_t) -1 ? -1 : (int) (t / USEC_PER_MSEC)); + struct timespec ts; + int r; + + r = ppoll(&pollfd, 1, t == (usec_t) -1 ? NULL : timespec_store(&ts, t), NULL); if (r < 0) return -errno; @@ -3968,7 +3893,7 @@ int fopen_temporary(const char *path, FILE **_f, char **_temp_path) { t[k] = '.'; stpcpy(stpcpy(t+k+1, fn), "XXXXXX"); - fd = mkostemp(t, O_WRONLY|O_CLOEXEC); + fd = mkostemp_safe(t, O_WRONLY|O_CLOEXEC); if (fd < 0) { free(t); return -errno; @@ -4137,7 +4062,7 @@ int symlink_atomic(const char *from, const char *to) { _cleanup_free_ char *t; const char *fn; size_t k; - unsigned long long ull; + uint64_t u; unsigned i; int r; @@ -4154,10 +4079,10 @@ int symlink_atomic(const char *from, const char *to) { t[k] = '.'; x = stpcpy(t+k+1, fn); - ull = random_ull(); + u = random_u64(); for (i = 0; i < 16; i++) { - *(x++) = hexchar(ull & 0xF); - ull >>= 4; + *(x++) = hexchar(u & 0xF); + u >>= 4; } *x = 0; @@ -5085,10 +5010,7 @@ int getenv_for_pid(pid_t pid, const char *field, char **_value) { assert(field); assert(_value); - if (pid == 0) - path = "/proc/self/environ"; - else - path = procfs_file_alloca(pid, "environ"); + path = procfs_file_alloca(pid, "environ"); f = fopen(path, "re"); if (!f) @@ -5984,8 +5906,20 @@ int proc_cmdline(char **ret) { int r; if (detect_container(NULL) > 0) { - *ret = NULL; - return 0; + char *buf, *p; + size_t sz = 0; + + r = read_full_file("/proc/1/cmdline", &buf, &sz); + if (r < 0) + return r; + + for (p = buf; p + 1 < buf + sz; p++) + if (*p == 0) + *p = ' '; + + *p = 0; + *ret = buf; + return 1; } r = read_one_line_file("/proc/cmdline", ret); @@ -6095,3 +6029,147 @@ bool pid_valid(pid_t pid) { return errno != ESRCH; } + +int getpeercred(int fd, struct ucred *ucred) { + socklen_t n = sizeof(struct ucred); + struct ucred u; + int r; + + assert(fd >= 0); + assert(ucred); + + r = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &u, &n); + if (r < 0) + return -errno; + + if (n != sizeof(struct ucred)) + return -EIO; + + /* Check if the data is actually useful and not suppressed due + * to namespacing issues */ + if (u.pid <= 0) + return -ENODATA; + + *ucred = u; + return 0; +} + +int getpeersec(int fd, char **ret) { + socklen_t n = 64; + char *s; + int r; + + assert(fd >= 0); + assert(ret); + + s = new0(char, n); + if (!s) + return -ENOMEM; + + r = getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n); + if (r < 0) { + free(s); + + if (errno != ERANGE) + return -errno; + + s = new0(char, n); + if (!s) + return -ENOMEM; + + r = getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n); + if (r < 0) { + free(s); + return -errno; + } + } + + if (isempty(s)) { + free(s); + return -ENOTSUP; + } + + *ret = s; + return 0; +} + +int writev_safe(int fd, const struct iovec *w, int j) { + for (int i = 0; i < j; i++) { + size_t written = 0; + + while (written < w[i].iov_len) { + ssize_t r; + + r = write(fd, (char*) w[i].iov_base + written, w[i].iov_len - written); + if (r < 0 && errno != -EINTR) + return -errno; + + written += r; + } + } + + return 0; +} + +int mkostemp_safe(char *pattern, int flags) { + unsigned long tries = TMP_MAX; + char *s; + int r; + _cleanup_umask_ mode_t u; + + assert(pattern); + + u = umask(077); + + /* This is much like like mkostemp() but avoids using any + * static variables, thus is async signal safe. Also, it's not + * subject to umask(). */ + + s = endswith(pattern, "XXXXXX"); + if (!s) + return -EINVAL; + + while (tries--) { + unsigned i; + int fd; + + r = dev_urandom(s, 6); + if (r < 0) + return r; + + for (i = 0; i < 6; i++) + s[i] = ALPHANUMERICAL[(unsigned) s[i] % (sizeof(ALPHANUMERICAL)-1)]; + + fd = open(pattern, flags|O_EXCL|O_CREAT|O_NOCTTY|O_NOFOLLOW, S_IRUSR|S_IWUSR); + if (fd >= 0) + return fd; + if (!IN_SET(errno, EEXIST, EINTR)) + return -errno; + } + + return -EEXIST; +} + +int open_tmpfile(const char *path, int flags) { + char *p; + int fd; + + assert(path); + +#ifdef O_TMPFILE + /* Try O_TMPFILE first, if it is supported */ + fd = open(path, flags|O_TMPFILE, S_IRUSR|S_IWUSR); + if (fd >= 0) + return fd; +#endif + + /* Fall back to unguessable name + unlinking */ + p = strappenda(path, "/systemd-tmp-XXXXXX"); + + fd = mkostemp_safe(p, flags); + if (fd < 0) + return fd; + + unlink(p); + return fd; +}