X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fbasic%2Ffileio.c;h=4ad2acf3bd7d9f5a404c1b04f89fe378f4a0d6f5;hp=f2a8f29e677c7180077959994c0cac76c24c4911;hb=d96290d8fd01ba77eec7f4a5fb493bc1ff80a98b;hpb=66ecc207e203db5434610395cd04c40ae8727b58 diff --git a/src/basic/fileio.c b/src/basic/fileio.c index f2a8f29e6..4ad2acf3b 100644 --- a/src/basic/fileio.c +++ b/src/basic/fileio.c @@ -47,6 +47,8 @@ #include "umask-util.h" #include "utf8.h" +#define READ_FULL_BYTES_MAX (4U*1024U*1024U) + int write_string_stream(FILE *f, const char *line, bool enforce_newline) { assert(f); @@ -230,7 +232,7 @@ int read_full_stream(FILE *f, char **contents, size_t *size) { if (S_ISREG(st.st_mode)) { /* Safety check */ - if (st.st_size > 4*1024*1024) + if (st.st_size > READ_FULL_BYTES_MAX) return -E2BIG; /* Start with the right file size, but be prepared for @@ -245,26 +247,31 @@ int read_full_stream(FILE *f, char **contents, size_t *size) { char *t; size_t k; - t = realloc(buf, n+1); + t = realloc(buf, n + 1); if (!t) return -ENOMEM; buf = t; k = fread(buf + l, 1, n - l, f); + if (k > 0) + l += k; - if (k <= 0) { - if (ferror(f)) - return -errno; + if (ferror(f)) + return -errno; + if (feof(f)) break; - } - l += k; - n *= 2; + /* We aren't expecting fread() to return a short read outside + * of (error && eof), assert buffer is full and enlarge buffer. + */ + assert(l == n); /* Safety check */ - if (n > 4*1024*1024) + if (n >= READ_FULL_BYTES_MAX) return -E2BIG; + + n = MIN(n * 2, READ_FULL_BYTES_MAX); } buf[l] = 0; @@ -352,7 +359,7 @@ static int parse_env_file_internal( case KEY: if (strchr(newline, c)) { state = PRE_KEY; - line ++; + line++; n_key = 0; } else if (c == '=') { state = PRE_VALUE; @@ -376,7 +383,7 @@ static int parse_env_file_internal( case PRE_VALUE: if (strchr(newline, c)) { state = PRE_KEY; - line ++; + line++; key[n_key] = 0; if (value) @@ -416,7 +423,7 @@ static int parse_env_file_internal( case VALUE: if (strchr(newline, c)) { state = PRE_KEY; - line ++; + line++; key[n_key] = 0; @@ -535,7 +542,7 @@ static int parse_env_file_internal( state = COMMENT_ESCAPE; else if (strchr(newline, c)) { state = PRE_KEY; - line ++; + line++; } break; @@ -588,7 +595,7 @@ static int parse_env_file_push( va_list aq, *ap = userdata; if (!utf8_is_valid(key)) { - _cleanup_free_ char *p; + _cleanup_free_ char *p = NULL; p = utf8_escape_invalid(key); log_error("%s:%u: invalid UTF-8 in key '%s', ignoring.", strna(filename), line, p); @@ -596,7 +603,7 @@ static int parse_env_file_push( } if (value && !utf8_is_valid(value)) { - _cleanup_free_ char *p; + _cleanup_free_ char *p = NULL; p = utf8_escape_invalid(value); log_error("%s:%u: invalid UTF-8 value for key %s: '%s', ignoring.", strna(filename), line, key, p); @@ -645,6 +652,7 @@ int parse_env_file( return r < 0 ? r : n_pushed; } +#if 0 /// UNNEEDED by elogind static int load_env_file_push( const char *filename, unsigned line, const char *key, char *value, @@ -700,7 +708,6 @@ int load_env_file(FILE *f, const char *fname, const char *newline, char ***rl) { return 0; } -#if 0 /// UNNEDED by elogind static int load_env_file_push_pairs( const char *filename, unsigned line, const char *key, char *value, @@ -759,7 +766,6 @@ int load_env_file_pairs(FILE *f, const char *fname, const char *newline, char ** *rl = m; return 0; } -#endif // 0 static void write_env_var(FILE *f, const char *v) { const char *p; @@ -821,7 +827,6 @@ int write_env_file(const char *fname, char **l) { return r; } -#if 0 /// UNNEEDED by elogind int executable_is_script(const char *path, char **interpreter) { int r; _cleanup_free_ char *line = NULL; @@ -882,13 +887,13 @@ int get_proc_field(const char *filename, const char *pattern, const char *termin do { t = strstr(t, pattern); - if (!t) - return -ENOENT; + if (!t) + return -ENOENT; /* Check that pattern occurs in beginning of line. */ pattern_ok = (t == status || t[-1] == '\n'); - t += strlen(pattern); + t += strlen(pattern); } while (!pattern_ok); @@ -912,7 +917,7 @@ int get_proc_field(const char *filename, const char *pattern, const char *termin /* Back off one char if there's nothing but whitespace and zeros */ if (!*t || isspace(*t)) - t --; + t--; } len = strcspn(t, terminator); @@ -1041,7 +1046,7 @@ int fopen_temporary(const char *path, FILE **_f, char **_temp_path) { if (r < 0) return r; - fd = mkostemp_safe(t, O_WRONLY|O_CLOEXEC); + fd = mkostemp_safe(t); if (fd < 0) { free(t); return -errno; @@ -1073,48 +1078,22 @@ int fflush_and_check(FILE *f) { return 0; } -/* This is much like like mkostemp() but is subject to umask(). */ -int mkostemp_safe(char *pattern, int flags) { - _cleanup_umask_ mode_t u; +/* This is much like mkostemp() but is subject to umask(). */ +int mkostemp_safe(char *pattern) { + _cleanup_umask_ mode_t u = 0; int fd; assert(pattern); u = umask(077); - fd = mkostemp(pattern, flags); + fd = mkostemp(pattern, O_CLOEXEC); if (fd < 0) return -errno; return fd; } -#if 0 /// UNNEEDED by elogind -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|O_EXCL, S_IRUSR|S_IWUSR); - if (fd >= 0) - return fd; -#endif - - /* Fall back to unguessable name + unlinking */ - p = strjoina(path, "/systemd-tmp-XXXXXX"); - - fd = mkostemp_safe(p, flags); - if (fd < 0) - return fd; - - unlink(p); - return fd; -} -#endif // 0 - int tempfn_xxxxxx(const char *p, const char *extra, char **ret) { const char *fn; char *t; @@ -1147,7 +1126,6 @@ int tempfn_xxxxxx(const char *p, const char *extra, char **ret) { return 0; } -#if 0 /// UNNEEDED by elogind int tempfn_random(const char *p, const char *extra, char **ret) { const char *fn; char *t, *x; @@ -1190,12 +1168,13 @@ int tempfn_random(const char *p, const char *extra, char **ret) { return 0; } +#if 0 /// UNNEEDED by elogind int tempfn_random_child(const char *p, const char *extra, char **ret) { char *t, *x; uint64_t u; unsigned i; + int r; - assert(p); assert(ret); /* Turns this: @@ -1204,6 +1183,12 @@ int tempfn_random_child(const char *p, const char *extra, char **ret) { * /foo/bar/waldo/.#3c2b6219aa75d7d0 */ + if (!p) { + r = tmp_dir(&p); + if (r < 0) + return r; + } + if (!extra) extra = ""; @@ -1287,4 +1272,145 @@ int fputs_with_space(FILE *f, const char *s, const char *separator, bool *space) return fputs(s, f); } + +int open_tmpfile_unlinkable(const char *directory, int flags) { + char *p; + int fd, r; + + if (!directory) { + r = tmp_dir(&directory); + if (r < 0) + return r; + } + + /* Returns an unlinked temporary file that cannot be linked into the file system anymore */ + + /* Try O_TMPFILE first, if it is supported */ + fd = open(directory, flags|O_TMPFILE|O_EXCL, S_IRUSR|S_IWUSR); + if (fd >= 0) + return fd; + + /* Fall back to unguessable name + unlinking */ + p = strjoina(directory, "/systemd-tmp-XXXXXX"); + + fd = mkostemp_safe(p); + if (fd < 0) + return fd; + + (void) unlink(p); + + return fd; +} + +int open_tmpfile_linkable(const char *target, int flags, char **ret_path) { + _cleanup_free_ char *tmp = NULL; + int r, fd; + + assert(target); + assert(ret_path); + + /* Don't allow O_EXCL, as that has a special meaning for O_TMPFILE */ + assert((flags & O_EXCL) == 0); + + /* Creates a temporary file, that shall be renamed to "target" later. If possible, this uses O_TMPFILE – in + * which case "ret_path" will be returned as NULL. If not possible a the tempoary path name used is returned in + * "ret_path". Use link_tmpfile() below to rename the result after writing the file in full. */ + + { + _cleanup_free_ char *dn = NULL; + + dn = dirname_malloc(target); + if (!dn) + return -ENOMEM; + + fd = open(dn, O_TMPFILE|flags, 0640); + if (fd >= 0) { + *ret_path = NULL; + return fd; + } + + log_debug_errno(errno, "Failed to use O_TMPFILE on %s: %m", dn); + } + + r = tempfn_random(target, NULL, &tmp); + if (r < 0) + return r; + + fd = open(tmp, O_CREAT|O_EXCL|O_NOFOLLOW|O_NOCTTY|flags, 0640); + if (fd < 0) + return -errno; + + *ret_path = tmp; + tmp = NULL; + + return fd; +} + +int link_tmpfile(int fd, const char *path, const char *target) { + + assert(fd >= 0); + assert(target); + + /* Moves a temporary file created with open_tmpfile() above into its final place. if "path" is NULL an fd + * created with O_TMPFILE is assumed, and linkat() is used. Otherwise it is assumed O_TMPFILE is not supported + * on the directory, and renameat2() is used instead. + * + * Note that in both cases we will not replace existing files. This is because linkat() does not support this + * operation currently (renameat2() does), and there is no nice way to emulate this. */ + + if (path) { + if (rename_noreplace(AT_FDCWD, path, AT_FDCWD, target) < 0) + return -errno; + } else { + char proc_fd_path[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(fd) + 1]; + + xsprintf(proc_fd_path, "/proc/self/fd/%i", fd); + + if (linkat(AT_FDCWD, proc_fd_path, AT_FDCWD, target, AT_SYMLINK_FOLLOW) < 0) + return -errno; + } + + return 0; +} #endif // 0 + +int read_nul_string(FILE *f, char **ret) { + _cleanup_free_ char *x = NULL; + size_t allocated = 0, n = 0; + + assert(f); + assert(ret); + + /* Reads a NUL-terminated string from the specified file. */ + + for (;;) { + int c; + + if (!GREEDY_REALLOC(x, allocated, n+2)) + return -ENOMEM; + + c = fgetc(f); + if (c == 0) /* Terminate at NUL byte */ + break; + if (c == EOF) { + if (ferror(f)) + return -errno; + break; /* Terminate at EOF */ + } + + x[n++] = (char) c; + } + + if (x) + x[n] = 0; + else { + x = new0(char, 1); + if (!x) + return -ENOMEM; + } + + *ret = x; + x = NULL; + + return 0; +}