[PATCH v4 4/4] conf: Add --dhcp-boot command-line option

[Anshu Kumari <anskuma@redhat.com>]

Add a convenience shorthand --dhcp-boot FILE that sets the boot file
name (DHCP option 67) for network boot.  This is equivalent to
--dhcp-opt 67,FILE.

Link: https://bugs.passt.top/show_bug.cgi?id=192
Signed-off-by: Anshu Kumari <anskuma@redhat.com>
---
v4:
  - Changed argument name from URL to FILE in usage and man page.
  - Fixed UEFI HTTP boot wording in man page

v3:
  - case 32 now calls dhcp_add_option(c, 67, optarg).
  - Handles duplicate codes: --dhcp-boot and --dhcp-opt 67 coexist
    correctly, last value wins.

v2:
  - Removed separate dhcp_boot[PATH_MAX] field — --dhcp-boot foo now stores into custom_opts[] as code 67 (same as --dhcp-opt 67,foo)

---
 conf.c  | 5 +++++
 passt.1 | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/conf.c b/conf.c
index 836b297..f100e0b 100644
--- a/conf.c
+++ b/conf.c
@@ -618,6 +618,7 @@ static void usage(const char *name, FILE *f, int status)
 		"    a single, empty option disables the DNS search list\n"
 		"  -H, --hostname NAME 	Hostname to configure client with\n"
 		"  --fqdn NAME		FQDN to configure client with\n"
+		"  --dhcp-boot FILE	Boot file name for network boot\n"
 		"  --dhcp-opt CODE,VAL	Set DHCP option CODE to VAL\n");
 	if (strstr(name, "pasta"))
 		FPRINTF(f, "    default: don't use any search list\n");
@@ -1258,6 +1259,7 @@ void conf(struct ctx *c, int argc, char **argv)
 		{"migrate-no-linger", no_argument,	NULL,		30 },
 		{"stats", required_argument,		NULL,		31 },
 		{"conf-path",	required_argument,	NULL,		'c' },
+		{"dhcp-boot", required_argument,	NULL,		33 },
 		{"dhcp-opt", required_argument,		NULL,		34 },
 		{ 0 },
 	};
@@ -1496,6 +1498,9 @@ void conf(struct ctx *c, int argc, char **argv)
 				die("Can't display statistics if not running in foreground");
 			c->stats = strtol(optarg, NULL, 0);
 			break;
+		case 33:
+			conf_dhcp_option(c, 67, optarg);
+			break;
 		case 34:
 			comma = strchr(optarg, ',');
 			if (!comma)
diff --git a/passt.1 b/passt.1
index ccdcbb2..f2341ef 100644
--- a/passt.1
+++ b/passt.1
@@ -430,6 +430,13 @@ Send \fIname\fR as DHCP option 12 (hostname).
 FQDN to configure the client with.
 Send \fIname\fR as Client FQDN: DHCP option 81 and DHCPv6 option 39.
 
+.TP
+.BR \-\-dhcp-boot " " \fIfile
+Convenience shorthand for \fB\-\-dhcp-opt\fR 67,\fIfile\fR.
+Sets the boot file name (DHCP option 67) for network boot.
+For UEFI HTTP boot, the vendor class identifier also needs to be set using
+\fB\-\-dhcp-opt\fR 60,HTTPClient.
+
 .TP
 .BR \-\-dhcp-opt " " \fICODE\fR,\fIVALUE\fR
 Set DHCP option \fICODE\fR (1\-254) to \fIVALUE\fR. The value format depends
-- 
2.54.0