1 files changed, 119 insertions, 0 deletions
diff --git a/src/misc/mntent.c b/src/misc/mntent.c
new file mode 100644
index 0000000..78bf0cd
--- /dev/null
+++ b/src/misc/mntent.c
@@ -0,0 +1,119 @@
+#include <stdio.h>
+#include <string.h>
+#include <mntent.h>
+#include <errno.h>
+#include <limits.h>
+
+static char *internal_buf;
+static size_t internal_bufsize;
+
+#define SENTINEL (char *)&internal_buf
+
+FILE *setmntent(const char *name, const char *mode)
+{
+	return fopen(name, mode);
+}
+
+int endmntent(FILE *f)
+{
+	if (f) fclose(f);
+	return 1;
+}
+
+static char *unescape_ent(char *beg)
+{
+	char *dest = beg;
+	const char *src = beg;
+	while (*src) {
+		const char *val;
+		unsigned char cval = 0;
+		if (*src != '\\') {
+			*dest++ = *src++;
+			continue;
+		}
+		if (src[1] == '\\') {
+			++src;
+			*dest++ = *src++;
+			continue;
+		}
+		val = src + 1;
+		for (int i = 0; i < 3; ++i) {
+			if (*val >= '0' && *val <= '7') {
+				cval <<= 3;
+				cval += *val++ - '0';
+			} else {
+				break;
+			}
+		}
+		if (cval) {
+			*dest++ = cval;
+			src = val;
+		} else {
+			*dest++ = *src++;
+		}
+	}
+	*dest = 0;
+	return beg;
+}
+
+struct mntent *getmntent_r(FILE *f, struct mntent *mnt, char *linebuf, int buflen)
+{
+	int n[8], use_internal = (linebuf == SENTINEL);
+	size_t len, i;
+
+	mnt->mnt_freq = 0;
+	mnt->mnt_passno = 0;
+
+	do {
+		if (use_internal) {
+			getline(&internal_buf, &internal_bufsize, f);
+			linebuf = internal_buf;
+		} else {
+			fgets(linebuf, buflen, f);
+		}
+		if (feof(f) || ferror(f)) return 0;
+		if (!strchr(linebuf, '\n')) {
+			fscanf(f, "%*[^\n]%*[\n]");
+			errno = ERANGE;
+			return 0;
+		}
+
+		len = strlen(linebuf);
+		if (len > INT_MAX) continue;
+		for (i = 0; i < sizeof n / sizeof *n; i++) n[i] = len;
+		sscanf(linebuf, " %n%*[^ \t]%n %n%*[^ \t]%n %n%*[^ \t]%n %n%*[^ \t]%n %d %d",
+			n, n+1, n+2, n+3, n+4, n+5, n+6, n+7,
+			&mnt->mnt_freq, &mnt->mnt_passno);
+	} while (linebuf[n[0]] == '#' || n[1]==len);
+
+	linebuf[n[1]] = 0;
+	linebuf[n[3]] = 0;
+	linebuf[n[5]] = 0;
+	linebuf[n[7]] = 0;
+
+	mnt->mnt_fsname = unescape_ent(linebuf+n[0]);
+	mnt->mnt_dir = unescape_ent(linebuf+n[2]);
+	mnt->mnt_type = unescape_ent(linebuf+n[4]);
+	mnt->mnt_opts = unescape_ent(linebuf+n[6]);
+
+	return mnt;
+}
+
+struct mntent *getmntent(FILE *f)
+{
+	static struct mntent mnt;
+	return getmntent_r(f, &mnt, SENTINEL, 0);
+}
+
+int addmntent(FILE *f, const struct mntent *mnt)
+{
+	if (fseek(f, 0, SEEK_END)) return 1;
+	return fprintf(f, "%s\t%s\t%s\t%s\t%d\t%d\n",
+		mnt->mnt_fsname, mnt->mnt_dir, mnt->mnt_type, mnt->mnt_opts,
+		mnt->mnt_freq, mnt->mnt_passno) < 0;
+}
+
+char *hasmntopt(const struct mntent *mnt, const char *opt)
+{
+	return strstr(mnt->mnt_opts, opt);
+}