X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=285a263cdbe5cc13a8946bc6c699e6e92fb88e43;hp=945f1525a266d73e70b4b188d3aac2da0bf27792;hb=840292befd6ad78e018f5ea16bec80e83d910071;hpb=7d5dd5e0cf2f0f2af39d72b1ee65651731bf0129

diff --git a/src/shared/util.c b/src/shared/util.c
index 945f1525a..285a263cd 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -58,6 +58,7 @@
 #include <limits.h>
 #include <langinfo.h>
 #include <locale.h>
+#include <sys/personality.h>
 #include <libgen.h>
 #undef basename
 
@@ -513,6 +514,31 @@ char *truncate_nl(char *s) {
         return s;
 }
 
+int get_process_state(pid_t pid) {
+        const char *p;
+        char state;
+        int r;
+        _cleanup_free_ char *line = NULL;
+
+        assert(pid >= 0);
+
+        p = procfs_file_alloca(pid, "stat");
+        r = read_one_line_file(p, &line);
+        if (r < 0)
+                return r;
+
+        p = strrchr(line, ')');
+        if (!p)
+                return -EIO;
+
+        p++;
+
+        if (sscanf(p, " %c", &state) != 1)
+                return -EIO;
+
+        return (unsigned char) state;
+}
+
 int get_process_comm(pid_t pid, char **name) {
         const char *p;
         int r;
@@ -761,28 +787,31 @@ char *strappend(const char *s, const char *suffix) {
         return strnappend(s, suffix, suffix ? strlen(suffix) : 0);
 }
 
-int readlink_malloc(const char *p, char **r) {
+int readlink_malloc(const char *p, char **ret) {
         size_t l = 100;
+        int r;
 
         assert(p);
-        assert(r);
+        assert(ret);
 
         for (;;) {
                 char *c;
                 ssize_t n;
 
-                if (!(c = new(char, l)))
+                c = new(char, l);
+                if (!c)
                         return -ENOMEM;
 
-                if ((n = readlink(p, c, l-1)) < 0) {
-                        int ret = -errno;
+                n = readlink(p, c, l-1);
+                if (n < 0) {
+                        r = -errno;
                         free(c);
-                        return ret;
+                        return r;
                 }
 
                 if ((size_t) n < l-1) {
                         c[n] = 0;
-                        *r = c;
+                        *ret = c;
                         return 0;
                 }
 
@@ -2106,30 +2135,71 @@ ssize_t loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
         return n;
 }
 
-int parse_bytes(const char *t, off_t *bytes) {
-        static const struct {
+int parse_size(const char *t, off_t base, off_t *size) {
+
+        /* Soo, sometimes we want to parse IEC binary suffxies, and
+         * sometimes SI decimal suffixes. This function can parse
+         * both. Which one is the right way depends on the
+         * context. Wikipedia suggests that SI is customary for
+         * hardrware metrics and network speeds, while IEC is
+         * customary for most data sizes used by software and volatile
+         * (RAM) memory. Hence be careful which one you pick!
+         *
+         * In either case we use just K, M, G as suffix, and not Ki,
+         * Mi, Gi or so (as IEC would suggest). That's because that's
+         * frickin' ugly. But this means you really need to make sure
+         * to document which base you are parsing when you use this
+         * call. */
+
+        struct table {
                 const char *suffix;
                 unsigned long long factor;
-        } table[] = {
-                { "B", 1 },
-                { "K", 1024ULL },
-                { "M", 1024ULL*1024ULL },
-                { "G", 1024ULL*1024ULL*1024ULL },
-                { "T", 1024ULL*1024ULL*1024ULL*1024ULL },
-                { "P", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
+        };
+
+        static const struct table iec[] = {
                 { "E", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
+                { "P", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
+                { "T", 1024ULL*1024ULL*1024ULL*1024ULL },
+                { "G", 1024ULL*1024ULL*1024ULL },
+                { "M", 1024ULL*1024ULL },
+                { "K", 1024ULL },
+                { "B", 1 },
                 { "", 1 },
         };
 
+        static const struct table si[] = {
+                { "E", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
+                { "P", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
+                { "T", 1000ULL*1000ULL*1000ULL*1000ULL },
+                { "G", 1000ULL*1000ULL*1000ULL },
+                { "M", 1000ULL*1000ULL },
+                { "K", 1000ULL },
+                { "B", 1 },
+                { "", 1 },
+        };
+
+        const struct table *table;
         const char *p;
         unsigned long long r = 0;
+        unsigned n_entries, start_pos = 0;
 
         assert(t);
-        assert(bytes);
+        assert(base == 1000 || base == 1024);
+        assert(size);
+
+        if (base == 1000) {
+                table = si;
+                n_entries = ELEMENTSOF(si);
+        } else {
+                table = iec;
+                n_entries = ELEMENTSOF(iec);
+        }
 
         p = t;
         do {
                 long long l;
+                unsigned long long l2;
+                double frac = 0;
                 char *e;
                 unsigned i;
 
@@ -2145,14 +2215,32 @@ int parse_bytes(const char *t, off_t *bytes) {
                 if (e == p)
                         return -EINVAL;
 
+                if (*e == '.') {
+                        e++;
+                        if (*e >= '0' && *e <= '9') {
+                                char *e2;
+
+                                /* strotoull itself would accept space/+/- */
+                                l2 = strtoull(e, &e2, 10);
+
+                                if (errno == ERANGE)
+                                        return -errno;
+
+                                /* Ignore failure. E.g. 10.M is valid */
+                                frac = l2;
+                                for (; e < e2; e++)
+                                        frac /= 10;
+                        }
+                }
+
                 e += strspn(e, WHITESPACE);
 
-                for (i = 0; i < ELEMENTSOF(table); i++)
+                for (i = start_pos; i < n_entries; i++)
                         if (startswith(e, table[i].suffix)) {
                                 unsigned long long tmp;
-                                if ((unsigned long long) l > ULLONG_MAX / table[i].factor)
+                                if ((unsigned long long) l + (frac > 0) > ULLONG_MAX / table[i].factor)
                                         return -ERANGE;
-                                tmp = l * table[i].factor;
+                                tmp = l * table[i].factor + (unsigned long long) (frac * table[i].factor);
                                 if (tmp > ULLONG_MAX - r)
                                         return -ERANGE;
 
@@ -2161,15 +2249,17 @@ int parse_bytes(const char *t, off_t *bytes) {
                                         return -ERANGE;
 
                                 p = e + strlen(table[i].suffix);
+
+                                start_pos = i + 1;
                                 break;
                         }
 
-                if (i >= ELEMENTSOF(table))
+                if (i >= n_entries)
                         return -EINVAL;
 
         } while (*p);
 
-        *bytes = r;
+        *size = r;
 
         return 0;
 }
@@ -2255,25 +2345,37 @@ char* dirname_malloc(const char *path) {
         return dir;
 }
 
-void random_bytes(void *p, size_t n) {
-        static bool srand_called = false;
+int dev_urandom(void *p, size_t n) {
         _cleanup_close_ int fd;
         ssize_t k;
-        uint8_t *q;
 
         fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
         if (fd < 0)
-                goto fallback;
+                return errno == ENOENT ? -ENOSYS : -errno;
 
         k = loop_read(fd, p, n, true);
-        if (k < 0 || (size_t) k != n)
-                goto fallback;
+        if (k < 0)
+                return (int) k;
+        if ((size_t) k != n)
+                return -EIO;
+
+        return 0;
+}
 
-        return;
+void random_bytes(void *p, size_t n) {
+        static bool srand_called = false;
+        uint8_t *q;
+        int r;
 
-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. */
 
         if (!srand_called) {
+                unsigned x = 0;
 
 #ifdef HAVE_SYS_AUXV_H
                 /* The kernel provides us with a bit of entropy in
@@ -2285,16 +2387,16 @@ fallback:
 
                 auxv = (void*) getauxval(AT_RANDOM);
                 if (auxv)
-                        srand(*(unsigned*) auxv);
-                else
+                        x ^= *(unsigned*) auxv;
 #endif
-                        srand(time(NULL) + gettid());
 
+                x ^= (unsigned) now(CLOCK_REALTIME);
+                x ^= (unsigned) gettid();
+
+                srand(x);
                 srand_called = true;
         }
 
-        /* If some idiot made /dev/urandom unavailable to us, he'll
-         * get a PRNG instead. */
         for (q = p; q < (uint8_t*) p + n; q ++)
                 *q = rand();
 }
@@ -2325,7 +2427,7 @@ void rename_process(const char name[8]) {
                         if (!saved_argv[i])
                                 break;
 
-                        memset(saved_argv[i], 0, strlen(saved_argv[i]));
+                        memzero(saved_argv[i], strlen(saved_argv[i]));
                 }
         }
 }
@@ -2485,9 +2587,11 @@ int get_ctty_devnr(pid_t pid, dev_t *d) {
 }
 
 int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
-        int k;
-        char fn[sizeof("/dev/char/")-1 + 2*DECIMAL_STR_MAX(unsigned) + 1 + 1], *s, *b, *p;
+        char fn[sizeof("/dev/char/")-1 + 2*DECIMAL_STR_MAX(unsigned) + 1 + 1], *b = NULL;
+        _cleanup_free_ char *s = NULL;
+        const char *p;
         dev_t devnr;
+        int k;
 
         assert(r);
 
@@ -2505,14 +2609,8 @@ int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
 
                 /* This is an ugly hack */
                 if (major(devnr) == 136) {
-                        if (asprintf(&b, "pts/%lu", (unsigned long) minor(devnr)) < 0)
-                                return -ENOMEM;
-
-                        *r = b;
-                        if (_devnr)
-                                *_devnr = devnr;
-
-                        return 0;
+                        asprintf(&b, "pts/%lu", (unsigned long) minor(devnr));
+                        goto finish;
                 }
 
                 /* Probably something like the ptys which have no
@@ -2520,14 +2618,7 @@ int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
                  * vaguely useful. */
 
                 b = strdup(fn + 5);
-                if (!b)
-                        return -ENOMEM;
-
-                *r = b;
-                if (_devnr)
-                        *_devnr = devnr;
-
-                return 0;
+                goto finish;
         }
 
         if (startswith(s, "/dev/"))
@@ -2538,8 +2629,8 @@ int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
                 p = s;
 
         b = strdup(p);
-        free(s);
 
+finish:
         if (!b)
                 return -ENOMEM;
 
@@ -2888,24 +2979,6 @@ int status_printf(const char *status, bool ellipse, bool ephemeral, const char *
         return r;
 }
 
-int status_welcome(void) {
-        _cleanup_free_ char *pretty_name = NULL, *ansi_color = NULL;
-        int r;
-
-        r = parse_env_file("/etc/os-release", NEWLINE,
-                           "PRETTY_NAME", &pretty_name,
-                           "ANSI_COLOR", &ansi_color,
-                           NULL);
-
-        if (r < 0 && r != -ENOENT)
-                log_warning("Failed to read /etc/os-release: %s", strerror(-r));
-
-        return status_printf(NULL, false, false,
-                             "\nWelcome to \x1B[%sm%s\x1B[0m!\n",
-                             isempty(ansi_color) ? "1" : ansi_color,
-                             isempty(pretty_name) ? "Linux" : pretty_name);
-}
-
 char *replace_env(const char *format, char **env) {
         enum {
                 WORD,
@@ -3823,12 +3896,13 @@ 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;
@@ -3880,7 +3954,7 @@ 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;
@@ -5597,7 +5671,7 @@ static int search_and_fopen_internal(const char *path, const char *mode, char **
         assert(mode);
         assert(_f);
 
-        if (!path_strv_canonicalize_uniq(search))
+        if (!path_strv_canonicalize_absolute_uniq(search, NULL))
                 return -ENOMEM;
 
         STRV_FOREACH(i, search) {
@@ -5779,7 +5853,7 @@ void* greedy_realloc0(void **p, size_t *allocated, size_t need) {
                 return NULL;
 
         if (*allocated > prev)
-                memset(&q[prev], 0, *allocated - prev);
+                memzero(&q[prev], *allocated - prev);
 
         return q;
 }
@@ -5825,20 +5899,6 @@ bool id128_is_valid(const char *s) {
         return true;
 }
 
-void parse_user_at_host(char *arg, char **user, char **host) {
-        assert(arg);
-        assert(user);
-        assert(host);
-
-        *host = strchr(arg, '@');
-        if (*host == NULL)
-                *host = arg;
-        else {
-                *host[0]++ = '\0';
-                *user = arg;
-        }
-}
-
 int split_pair(const char *s, const char *sep, char **l, char **r) {
         char *x, *a, *b;
 
@@ -5893,7 +5953,7 @@ int proc_cmdline(char **ret) {
         int r;
 
         if (detect_container(NULL) > 0) {
-                char *buf, *p;
+                char *buf = NULL, *p;
                 size_t sz = 0;
 
                 r = read_full_file("/proc/1/cmdline", &buf, &sz);
@@ -5916,6 +5976,35 @@ int proc_cmdline(char **ret) {
         return 1;
 }
 
+int parse_proc_cmdline(int (*parse_word)(const char *word)) {
+        _cleanup_free_ char *line = NULL;
+        char *w, *state;
+        size_t l;
+        int r;
+
+        r = proc_cmdline(&line);
+        if (r < 0)
+                log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
+        if (r <= 0)
+                return 0;
+
+        FOREACH_WORD_QUOTED(w, l, line, state) {
+                _cleanup_free_ char *word;
+
+                word = strndup(w, l);
+                if (!word)
+                        return log_oom();
+
+                r = parse_word(word);
+                if (r < 0) {
+                        log_error("Failed on cmdline argument %s: %s", word, strerror(-r));
+                        return r;
+                }
+        }
+
+        return 0;
+}
+
 int container_get_leader(const char *machine, pid_t *pid) {
         _cleanup_free_ char *s = NULL, *class = NULL;
         const char *p;
@@ -6007,7 +6096,9 @@ int namespace_enter(int pidns_fd, int mntns_fd, int root_fd) {
         return 0;
 }
 
-bool pid_valid(pid_t pid) {
+bool pid_is_unwaited(pid_t pid) {
+        /* Checks whether a PID is still valid at all, including a zombie */
+
         if (pid <= 0)
                 return false;
 
@@ -6017,6 +6108,21 @@ bool pid_valid(pid_t pid) {
         return errno != ESRCH;
 }
 
+bool pid_is_alive(pid_t pid) {
+        int r;
+
+        /* Checks whether a PID is still valid and not a zombie */
+
+        if (pid <= 0)
+                return false;
+
+        r = get_process_state(pid);
+        if (r == -ENOENT || r == 'Z')
+                return false;
+
+        return true;
+}
+
 int getpeercred(int fd, struct ucred *ucred) {
         socklen_t n = sizeof(struct ucred);
         struct ucred u;
@@ -6080,68 +6186,108 @@ int getpeersec(int fd, char **ret) {
         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;
-}
-
+/* This is much like like mkostemp() but is subject to umask(). */
 int mkostemp_safe(char *pattern, int flags) {
-        char *s = pattern + strlen(pattern) - 6;
-        uint64_t tries = TMP_MAX;
-        int randfd, fd, i;
-
-        assert(streq(s, "XXXXXX"));
-
-        randfd = open("/dev/urandom", O_RDONLY);
-        if (randfd < 0)
-                return -ENOSYS;
+        _cleanup_umask_ mode_t u;
+        int fd;
 
-        while (tries--) {
-                fd = read(randfd, s, 6);
-                if (fd == 0)
-                        return -ENOSYS;
+        assert(pattern);
 
-                for (i = 0; i < 6; i++)
-                        s[i] = ALPHANUMERICAL[(unsigned) s[i] % strlen(ALPHANUMERICAL)];
+        u = umask(077);
 
-                fd = open(pattern, flags|O_EXCL|O_CREAT, S_IRUSR|S_IWUSR);
-                if (fd >= 0)
-                        return fd;
-                if (!IN_SET(errno, EEXIST, EINTR))
-                        return -errno;
-        }
+        fd = mkostemp(pattern, flags);
+        if (fd < 0)
+                return -errno;
 
-        return -EEXIST;
+        return fd;
 }
 
 int open_tmpfile(const char *path, int flags) {
-        int fd;
         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, O_RDWR|O_CLOEXEC);
+        fd = mkostemp_safe(p, flags);
         if (fd < 0)
                 return fd;
 
         unlink(p);
         return fd;
 }
+
+int fd_warn_permissions(const char *path, int fd) {
+        struct stat st;
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        if (st.st_mode & 0111)
+                log_warning("Configuration file %s is marked executable. Please remove executable permission bits. Proceeding anyway.", path);
+
+        if (st.st_mode & 0002)
+                log_warning("Configuration file %s is marked world-writable. Please remove world writability permission bits. Proceeding anyway.", path);
+
+        if (getpid() == 1 && (st.st_mode & 0044) != 0044)
+                log_warning("Configuration file %s is marked world-inaccessible. This has no effect as configuration data is accessible via APIs without restrictions. Proceeding anyway.", path);
+
+        return 0;
+}
+
+unsigned long personality_from_string(const char *p) {
+
+        /* Parse a personality specifier. We introduce our own
+         * identifiers that indicate specific ABIs, rather than just
+         * hints regarding the register size, since we want to keep
+         * things open for multiple locally supported ABIs for the
+         * same register size. We try to reuse the ABI identifiers
+         * used by libseccomp. */
+
+#if defined(__x86_64__)
+
+        if (streq(p, "x86"))
+                return PER_LINUX32;
+
+        if (streq(p, "x86-64"))
+                return PER_LINUX;
+
+#elif defined(__i386__)
+
+        if (streq(p, "x86"))
+                return PER_LINUX;
+#endif
+
+        /* personality(7) documents that 0xffffffffUL is used for
+         * querying the current personality, hence let's use that here
+         * as error indicator. */
+        return 0xffffffffUL;
+}
+
+const char* personality_to_string(unsigned long p) {
+
+#if defined(__x86_64__)
+
+        if (p == PER_LINUX32)
+                return "x86";
+
+        if (p == PER_LINUX)
+                return "x86-64";
+
+#elif defined(__i386__)
+
+        if (p == PER_LINUX)
+                return "x86";
+#endif
+
+        return NULL;
+}