GopherProxy

	Improve tokenization for m- and v-flag parsing - quark - quark web server
	git clone git://git.suckless.org/quark
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	---
	commit 33def953e9d216036ad921ac26052a5b0fa790dc
	parent 065394cb64395ed9a6e7cc57e2519ee8f754ce3e
	Author: Laslo Hunhold <[email protected]>
	Date: Sun, 24 Feb 2019 21:50:39 +0100

	Improve tokenization for m- and v-flag parsing

	I wasn't happy with the tokenizer for the m- and v-flags, because it
	was handling space-separated input and there was no way to have spaces
	within the tokens themselves. This is a fine detail, but I didn't want
	to impose this restriction where it could be solved (path prefixes or
	folder names can very well contain spaces).

	Given it's a bit quirky to handle multiple arguments to a single flag
	in the command line, especially when parameters are optional, this
	alternative wasn't further considered and I instead implemented a
	tokenizer that allows escaping spaces with '\'.

	While at it, I clarified the manual regarding this point.

	Signed-off-by: Laslo Hunhold <[email protected]>

	Diffstat:
	M main.c \| 106 ++++++++++++++++++++++++-----…
	M quark.1 \| 6 ++++--

	2 files changed, 88 insertions(+), 24 deletions(-)
	---
	diff --git a/main.c b/main.c
	@@ -90,6 +90,77 @@ handlesignals(void(*hdl)(int))
	sigaction(SIGQUIT, &sa, NULL);
	}

	+static int
	+spacetok(const char s, char *t, size_t tlen)
	+{
	+ const char *tok;
	+ size_t i, j, toki, spaces;
	+
	+ /* fill token-array with NULL-pointers */
	+ for (i = 0; i < tlen; i++) {
	+ t[i] = NULL;
	+ }
	+ toki = 0;
	+
	+ /* don't allow NULL string or leading spaces */
	+ if (!s \|\| *s == ' ') {
	+ return 1;
	+ }
	+start:
	+ /* skip spaces */
	+ for (; *s == ' '; s++)
	+ ;
	+
	+ /* don't allow trailing spaces */
	+ if (*s == '\0') {
	+ goto err;
	+ }
	+
	+ /* consume token */
	+ for (tok = s, spaces = 0; ; s++) {
	+ if (s == '\\' && (s + 1) == ' ') {
	+ spaces++;
	+ s++;
	+ continue;
	+ } else if (*s == ' ') {
	+ /* end of token */
	+ goto token;
	+ } else if (*s == '\0') {
	+ /* end of string */
	+ goto token;
	+ }
	+ }
	+token:
	+ if (toki >= tlen) {
	+ goto err;
	+ }
	+ if (!(t[toki] = malloc(s - tok - spaces + 1))) {
	+ die("malloc:");
	+ }
	+ for (i = 0, j = 0; j < s - tok - spaces + 1; i++, j++) {
	+ if (tok[i] == '\\' && tok[i + 1] == ' ') {
	+ i++;
	+ }
	+ t[toki][j] = tok[i];
	+ }
	+ t[toki][s - tok - spaces] = '\0';
	+ toki++;
	+
	+ if (*s == ' ') {
	+ s++;
	+ goto start;
	+ }
	+
	+ return 0;
	+err:
	+ for (i = 0; i < tlen; i++) {
	+ free(t[i]);
	+ t[i] = NULL;
	+ }
	+
	+ return 1;
	+}
	+
	static void
	usage(void)
	{
	@@ -113,7 +184,7 @@ main(int argc, char *argv[])
	socklen_t in_sa_len;
	int insock, status = 0, infd;
	const char *err;
	- char *tok;
	+ char *tok[4];

	/* defaults */
	int maxnprocs = 512;
	@@ -148,21 +219,16 @@ main(int argc, char *argv[])
	s.listdirs = 1;
	break;
	case 'm':
	- if (!(tok = strdup(EARGF(usage())))) {
	- die("strdup:");
	+ if (spacetok(EARGF(usage()), tok, 3) \|\| !tok[0] \|\| !tok[1]) {
	+ usage();
	}
	if (!(s.map = reallocarray(s.map, ++s.map_len,
	sizeof(struct map)))) {
	die("reallocarray:");
	}
	- if (!(s.map[s.map_len - 1].from = strtok(tok, " ")) \|\|
	- !(s.map[s.map_len - 1].to = strtok(NULL, " "))) {
	- usage();
	- }
	- s.map[s.map_len - 1].chost = strtok(NULL, " ");
	- if (strtok(NULL, "")) {
	- usage();
	- }
	+ s.map[s.map_len - 1].from = tok[0];
	+ s.map[s.map_len - 1].to = tok[1];
	+ s.map[s.map_len - 1].chost = tok[2];
	break;
	case 'n':
	maxnprocs = strtonum(EARGF(usage()), 1, INT_MAX, &err);
	@@ -180,22 +246,18 @@ main(int argc, char *argv[])
	user = EARGF(usage());
	break;
	case 'v':
	- if (!(tok = strdup(EARGF(usage())))) {
	- die("strdup:");
	+ if (spacetok(EARGF(usage()), tok, 4) \|\| !tok[0] \|\| !tok[1] \|\|
	+ !tok[2]) {
	+ usage();
	}
	if (!(s.vhost = reallocarray(s.vhost, ++s.vhost_len,
	sizeof(struct vhost)))) {
	die("reallocarray:");
	}
	- if (!(s.vhost[s.vhost_len - 1].chost = strtok(tok, " ")) \|\|
	- !(s.vhost[s.vhost_len - 1].regex = strtok(NULL, " ")) \|\|
	- !(s.vhost[s.vhost_len - 1].dir = strtok(NULL, " "))) {
	- usage();
	- }
	- s.vhost[s.vhost_len - 1].prefix = strtok(NULL, " ");
	- if (strtok(NULL, "")) {
	- usage();
	- }
	+ s.vhost[s.vhost_len - 1].chost = tok[0];
	+ s.vhost[s.vhost_len - 1].regex = tok[1];
	+ s.vhost[s.vhost_len - 1].dir = tok[2];
	+ s.vhost[s.vhost_len - 1].prefix = tok[3];
	break;
	default:
	usage();
	diff --git a/quark.1 b/quark.1
	@@ -58,7 +58,8 @@ Add the target prefix mapping rule specified by
	.Ar map ,
	which has the form
	.Qq Pa from to [chost] ,
	-where each element is separated with whitespace.
	+where each element is separated with spaces (0x20) that can be
	+escaped with '\\'.
	.Pp
	The prefix
	.Pa from
	@@ -96,7 +97,8 @@ Add the virtual host specified by
	.Ar vhost ,
	which has the form
	.Qq Pa chost regex dir [prefix] ,
	-where each element is separated with whitespace.
	+where each element is separated with spaces (0x20) that can be
	+escaped with '\\'.
	.Pp
	A request matching the virtual host regular expression
	.Pa regex