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Thu, 09 Jan 2025 04:57:50 -0800 (PST) X-Google-Smtp-Source: AGHT+IFu96lXCO+UORs1gVNfWtuFsYAbzKUA8ZnIplvJWmDAD0Uz1QY6rHMCjPdIH1zKh3DTDVG9YM9M4nqvtn+11bs= X-Received: by 2002:a17:906:7315:b0:aab:7289:fcd4 with SMTP id a640c23a62f3a-ab2c3d4c486mr274366866b.19.1736427469786; Thu, 09 Jan 2025 04:57:49 -0800 (PST) MIME-Version: 1.0 References: <20250108145811.833308-1-ellorent@redhat.com> <20250109091631.03fefb0e@elisabeth> In-Reply-To: <20250109091631.03fefb0e@elisabeth> From: Enrique Llorente Pastora Date: Thu, 9 Jan 2025 13:57:38 +0100 X-Gm-Features: AbW1kvZSFrgIRtLgLhE2CwOJGThDQWreaXcxmXIYQ3s0YaVllajuoVZ8idshAG8 Message-ID: Subject: Re: [PATCH v7] dhcp, dhcpv6: Add hostname and client fqdn ops To: Stefano Brivio X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: UGpoPBPQfOgRQiKscJa6e9FZfBy8wsxu88DevtG6USM_1736427472 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Message-ID-Hash: Y7HHR2IEPLEKIEXVMK6DM2AY4NM7N72C X-Message-ID-Hash: Y7HHR2IEPLEKIEXVMK6DM2AY4NM7N72C X-MailFrom: ellorent@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: passt-dev@passt.top X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Thu, Jan 9, 2025 at 9:16=E2=80=AFAM Stefano Brivio = wrote: > > Just coding style comments, plus one functional issue, but it should be > relatively contained: > > On Wed, 8 Jan 2025 15:58:11 +0100 > Enrique Llorente wrote: > > > Both DHCPv4 and DHCPv6 has the capability to pass the hostname to > > clients, the DHCPv4 uses option 12 (hostname) while the DHCPv6 uses opt= ion 39 > > (client fqdn), for some virt deployments like kubevirt is expected to > > have the VirtualMachine name as the guest hostname. > > > > This change add the following arguments: > > - -H --hostname NAME to configure the hostname DHCPv4 option(12) > > - --fqdn NAME to configure client fqdn option for both DHCPv4(81) and > > DHCPv6(39) > > > > Signed-off-by: Enrique Llorente > > --- > > conf.c | 20 ++++++++++-- > > dhcp.c | 54 ++++++++++++++++++++++++++---- > > dhcpv6.c | 85 +++++++++++++++++++++++++++++++++++++++--------- > > passt.1 | 10 ++++++ > > passt.h | 5 +++ > > pasta.c | 17 +++++++--- > > test/lib/setup | 10 +++--- > > test/passt.mbuto | 6 ++-- > > test/passt/dhcp | 15 ++++++++- > > util.c | 31 ++++++++++++++++++ > > util.h | 6 ++++ > > 11 files changed, 222 insertions(+), 37 deletions(-) > > > > diff --git a/conf.c b/conf.c > > index df2b016..554e5c3 100644 > > --- a/conf.c > > +++ b/conf.c > > @@ -854,7 +854,9 @@ static void usage(const char *name, FILE *f, int st= atus) > > FPRINTF(f, " default: use addresses from /etc/resolv.c= onf\n"); > > FPRINTF(f, > > " -S, --search LIST Space-separated list, search doma= ins\n" > > - " a single, empty option disables the DNS search list\= n"); > > + " 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")= ; > > if (strstr(name, "pasta")) > > FPRINTF(f, " default: don't use any search list\n"); > > else > > @@ -1313,6 +1315,7 @@ void conf(struct ctx *c, int argc, char **argv) > > {"outbound", required_argument, NULL, '= o' }, > > {"dns", required_argument, NULL, '= D' }, > > {"search", required_argument, NULL, '= S' }, > > + {"hostname", required_argument, NULL, '= H' }, > > {"no-tcp", no_argument, &c->no_tcp, 1= }, > > {"no-udp", no_argument, &c->no_udp, 1= }, > > {"no-icmp", no_argument, &c->no_icmp, 1= }, > > @@ -1357,6 +1360,7 @@ void conf(struct ctx *c, int argc, char **argv) > > /* vhost-user backend program convention */ > > {"print-capabilities", no_argument, NULL, 2= 6 }, > > {"socket-path", required_argument, NULL, '= s' }, > > + {"fqdn", required_argument, NULL, 2= 7 }, > > { 0 }, > > }; > > const char *logname =3D (c->mode =3D=3D MODE_PASTA) ? "pasta" : "= passt"; > > @@ -1379,9 +1383,9 @@ void conf(struct ctx *c, int argc, char **argv) > > if (c->mode =3D=3D MODE_PASTA) { > > c->no_dhcp_dns =3D c->no_dhcp_dns_search =3D 1; > > fwd_default =3D FWD_AUTO; > > - optstring =3D "+dqfel:hF:I:p:P:m:a:n:M:g:i:o:D:S:46t:u:T:= U:"; > > + optstring =3D "+dqfel:hF:I:p:P:m:a:n:M:g:i:o:D:S:H:46t:u:= T:U:"; > > } else { > > - optstring =3D "+dqfel:hs:F:p:P:m:a:n:M:g:i:o:D:S:461t:u:"= ; > > + optstring =3D "+dqfel:hs:F:p:P:m:a:n:M:g:i:o:D:S:H:461t:u= :"; > > } > > > > c->tcp.fwd_in.mode =3D c->tcp.fwd_out.mode =3D FWD_UNSET; > > @@ -1558,6 +1562,11 @@ void conf(struct ctx *c, int argc, char **argv) > > case 26: > > vu_print_capabilities(); > > break; > > + case 27: > > + if (snprintf_check(c->fqdn, PASST_MAXDNAME, > > + "%s", optarg)) > > + die("Invalid FQDN: %s", optarg); > > + break; > > case 'd': > > c->debug =3D 1; > > c->quiet =3D 0; > > @@ -1727,6 +1736,11 @@ void conf(struct ctx *c, int argc, char **argv) > > > > die("Cannot use DNS search domain %s", optarg); > > break; > > + case 'H': > > + if (snprintf_check(c->hostname, PASST_MAXDNAME, > > + = "%s", optarg)) > > Why? This was fine in v6. I'm not sure what happened here. In case your > editor/email client doesn't show this, now it's: > > tab tab tab tab tab tab tab tab tab tab tab tab space "%s", optarg)) > > that is, twelve tabs and one space. See also: > > https://archives.passt.top/passt-dev/20250108145811.833308-1-ellorent@r= edhat.com/#Z31conf.c > > It should be: > > if (snprintf_check(c->hostname, PASST_MAXDNAME, > "%s", optarg)) > > tab tab tab tab tab space space space "%s", optarg)) > > that is, five tabs and three spaces. > Fixed, no clue how I de-formated it. > > + die("Invalid hostname: %s", optarg); > > + break; > > case '4': > > v4_only =3D true; > > v6_only =3D false; > > diff --git a/dhcp.c b/dhcp.c > > index d8515aa..50c220d 100644 > > --- a/dhcp.c > > +++ b/dhcp.c > > @@ -63,6 +63,11 @@ static struct opt opts[255]; > > > > #define OPT_MIN 60 /* RFC 951 */ > > > > +/* Total option size (excluding end option) is 576 (RFC 2131), minus > > + * offset of options (268), minus end option and its length (2). > > + */ > > +#define OPT_MAX 306 > > + > > /** > > * dhcp_init() - Initialise DHCP options > > */ > > @@ -122,7 +127,7 @@ struct msg { > > uint8_t sname[64]; > > uint8_t file[128]; > > uint32_t magic; > > - uint8_t o[308]; > > + uint8_t o[OPT_MAX + 2/*End option and its length*/]; > > Same as my comment to v6: > > "Spaces around /* ... */ wouldn't be bad for readability." > Right, I understood the opposite, fixing. > > } __attribute__((__packed__)); > > > > /** > > @@ -130,15 +135,28 @@ struct msg { > > * @m: Message to fill > > * @o: Option number > > * @offset: Current offset within options field, updated on insertion > > + * > > + * Return: offset for the next option field or -1 if option do not fit > > Same as my comment to v6: > > "doesn't fit" > > It's a bit weird, but harmless, that this function updates 'offset', > and also returns it (unless there's an error). Maybe it saves a bit of > typing in callers, though (I would have just returned offset or -1 at > this point, without passing a pointer). > Make sense to not pass a pointer to offset, I will change it. > > */ > > -static void fill_one(struct msg *m, int o, int *offset) > > +static ssize_t fill_one(struct msg *m, int o, int *offset) > > { > > + size_t slen =3D opts[o].slen; > > + > > + /* If we don't have space to write the option, then just skip */ > > + if (*offset + 1 /* length of option */ + slen > OPT_MAX) > > + return -1; > > + > > m->o[*offset] =3D o; > > - m->o[*offset + 1] =3D opts[o].slen; > > - memcpy(&m->o[*offset + 2], opts[o].s, opts[o].slen); > > + m->o[*offset + 1] =3D slen; > > + > > + /* Move to option */ > > + *offset +=3D 2; > > + > > + memcpy(&m->o[*offset], opts[o].s, slen); > > > > opts[o].sent =3D 1; > > - *offset +=3D 2 + opts[o].slen; > > + *offset +=3D slen; > > + return *offset; > > } > > > > /** > > @@ -171,8 +189,11 @@ static int fill(struct msg *m) > > } > > > > for (o =3D 0; o < 255; o++) { > > - if (opts[o].slen !=3D -1 && !opts[o].sent) > > - fill_one(m, o, &offset); > > + if (opts[o].slen !=3D -1 && !opts[o].sent) { > > + if (fill_one(m, o, &offset) =3D=3D -1) { > > Curly brackets not needed. > Done. > > + debug("DHCP: skipping option %i", o); > > + } > > + } > > } > > > > m->o[offset++] =3D 255; > > @@ -398,6 +419,25 @@ int dhcp(const struct ctx *c, const struct pool *p= ) > > if (!opts[6].slen) > > opts[6].slen =3D -1; > > > > + opt_len =3D strlen(c->hostname); > > + if (opt_len > 0) { > > + opts[12].slen =3D opt_len; > > + memcpy(opts[12].s, &c->hostname, opt_len); > > + } > > + > > + opt_len =3D strlen(c->fqdn); > > + if (opt_len > 0) { > > + size_t encoded_len; > > + encoded_len =3D encode_domain_name((char *)opts[81].s + 3= , sizeof(opts[81].s) - 3, > > + c->fqdn, opt_len); > > Arguments are aligned properly, but it exceeds 80 columns for no > compelling reason. It should be: > > encoded_len =3D encode_domain_name((char *)opts[81].s + 3= , > sizeof(opts[81].s) - 3, > c->fqdn, opt_len); > Done. > > + if (encoded_len > 0 ) { > > Excess whitespace between 0 and ). > Done. > > + opts[81].s[0] =3D 0x4; /* flags (E) */ > > + opts[81].s[1] =3D 0xff; /* RCODE1 */ > > + opts[81].s[2] =3D 0xff; /* RCODE2 */ > > + opts[81].slen =3D encoded_len + 3; > > + } > > + } > > + > > if (!c->no_dhcp_dns_search) > > opt_set_dns_search(c, sizeof(m->o)); > > > > diff --git a/dhcpv6.c b/dhcpv6.c > > index 0523bba..07ce768 100644 > > --- a/dhcpv6.c > > +++ b/dhcpv6.c > > @@ -48,6 +48,7 @@ struct opt_hdr { > > # define STATUS_NOTONLINK htons_constant(4) > > # define OPT_DNS_SERVERS htons_constant(23) > > # define OPT_DNS_SEARCH htons_constant(24) > > +# define OPT_CLIENT_FQDN htons_constant(39) > > #define STR_NOTONLINK "Prefix not appropriate for link.= " > > > > uint16_t l; > > @@ -58,6 +59,9 @@ struct opt_hdr { > > sizeof(struct opt_hdr)) > > #define OPT_VSIZE(x) (sizeof(struct opt_##x) - \ > > sizeof(struct opt_hdr)) > > +#define OPT_MAX_SIZE IPV6_MIN_MTU - (sizeof(struct ipv6hdr) + = \ > > + sizeof(struct udphdr) + \ > > + sizeof(struct msg_hdr)) > > > > /** > > * struct opt_client_id - DHCPv6 Client Identifier option > > @@ -163,6 +167,18 @@ struct opt_dns_search { > > char list[MAXDNSRCH * NS_MAXDNAME]; > > } __attribute__((packed)); > > > > +/** > > + * struct opt_client_fqdn - Client FQDN option (RFC 4704) > > + * @hdr: Option header > > + * @flags: Flags described by RFC 4704 > > + * @domain_name: Client FQDN > > + */ > > +struct opt_client_fqdn { > > + struct opt_hdr hdr; > > + uint8_t flags; > > + char domain_name[PASST_MAXDNAME]; > > +} __attribute__((packed)); > > + > > /** > > * struct msg_hdr - DHCPv6 client/server message header > > * @type: DHCP message type > > @@ -193,6 +209,7 @@ struct msg_hdr { > > * @client_id: Client Identifier, variable length > > * @dns_servers: DNS Recursive Name Server, here just for storage = size > > * @dns_search: Domain Search List, here just for storage= size > > + * @client_fqdn: Client FQDN, variable length > > */ > > static struct resp_t { > > struct msg_hdr hdr; > > @@ -203,6 +220,7 @@ static struct resp_t { > > struct opt_client_id client_id; > > struct opt_dns_servers dns_servers; > > struct opt_dns_search dns_search; > > + struct opt_client_fqdn client_fqdn; > > } __attribute__((__packed__)) resp =3D { > > { 0 }, > > SERVER_ID, > > @@ -228,6 +246,10 @@ static struct resp_t { > > { { OPT_DNS_SEARCH, 0, }, > > { 0 }, > > }, > > + > > + { { OPT_CLIENT_FQDN, 0, }, > > + 0, { 0 }, > > + }, > > }; > > > > static const struct opt_status_code sc_not_on_link =3D { > > @@ -346,7 +368,6 @@ static size_t dhcpv6_dns_fill(const struct ctx *c, = char *buf, int offset) > > { > > struct opt_dns_servers *srv =3D NULL; > > struct opt_dns_search *srch =3D NULL; > > - char *p =3D NULL; > > int i; > > > > if (c->no_dhcp_dns) > > @@ -373,6 +394,7 @@ search: > > return offset; > > > > for (i =3D 0; *c->dns_search[i].n; i++) { > > + size_t encoded_name_len; > > size_t name_len =3D strlen(c->dns_search[i].n); > > > > /* We already append separators, don't duplicate if prese= nt */ > > @@ -388,29 +410,61 @@ search: > > offset +=3D sizeof(struct opt_hdr); > > srch->hdr.t =3D OPT_DNS_SEARCH; > > srch->hdr.l =3D 0; > > - p =3D srch->list; > > } > > > > - *p =3D '.'; > > - p =3D stpncpy(p + 1, c->dns_search[i].n, name_len); > > - p++; > > - srch->hdr.l +=3D name_len + 2; > > - offset +=3D name_len + 2; > > + encoded_name_len =3D encode_domain_name(srch->list, NS_MA= XDNAME, > > + c->dns_search[i].n, > > + name_len); > > + srch->hdr.l +=3D encoded_name_len; > > ...not if encoded_name_len is -1. In that case, you could also have an > integer overflow, other than broken functionality. > Right, I will check -1 and skip on that case. Also I have to move the list buffer or I will be storing it at the first element. encoded_name_len =3D encode_domain_name(srch->list + srch->hdr.l, NS_MAXDNAME, c->dns_search[i].n, name_len); > > + offset +=3D encoded_name_len; > > } > > > > - if (srch) { > > - for (i =3D 0; i < srch->hdr.l; i++) { > > - if (srch->list[i] =3D=3D '.') { > > - srch->list[i] =3D strcspn(srch->list + i = + 1, > > - "."); > > - } > > - } > > + if (srch) > > srch->hdr.l =3D htons(srch->hdr.l); > > - } > > > > return offset; > > } > > > > +/** > > + * dhcpv6_client_fqdn_fill() - Fill in client FQDN option > > + * @c: Execution context > > + * @buf: Response message buffer where options will be appended > > + * @offset: Offset in message buffer for new options > > + * > > + * Return: updated length of response message buffer. > > + */ > > +static size_t dhcpv6_client_fqdn_fill(const struct pool *p, const stru= ct ctx *c, > > + char *buf, int offset) > > + > > +{ > > + ssize_t opt_len; > > + struct opt_client_fqdn *o; > > + struct opt_client_fqdn const *req_opt; > > Same as my comment to v6: > > "These should go from longest to shortest." > Done. > > + > > + opt_len =3D MIN(PASST_MAXDNAME, OPT_MAX_SIZE - (offset + sizeof(s= truct opt_hdr) + 1/*flags*/)); > > This should be PASST_MAXDNAME + 1, otherwise: > > ./passt -d -f --fqdn thirtytwocharactersforeachlabel.thirtytwocharactersf= oreachlabel.thirtytwocharactersforeachlabel.thirtytwocharactersforeachlabel= .thirtytwocharactersforeachlabel.thirtytwocharactersforeachlabel.thirtytwoc= haractersforeachlabel.and_get_to_252_with_this_one > > 19.4621: DHCPv6: received REQUEST/RENEW/CONFIRM, sending REPLY > 19.4621: DHCPv6: client FQDN option does not fit, skipping > Make sense I will change it > ...but that domain name is 252 characters, and it's accepted > (longer domains are not accepted, which makes me think: should > PASST_MAXDNAME be 254 instead, as it includes the terminator?). > We are also using that const for validation (and on that case we don't count the terminator) so we cannot modify it if (snprintf_check(c->fqdn, PASST_MAXDNAME, "%s", optarg)) die("Invalid FQDN: %s", optarg); > If it's one byte shorter, then it works (254 bytes option > size, 253 bytes of encoded domain, 251 of original domain). > > Once this is fixed, this reveals an issue in encode_domain_name(), more > on that below. > > By the way, this exceeds 80 columns for no particular reason, and > "+ 1 /* flags */" is probably a bit more readable. > > > + > > + o =3D (struct opt_client_fqdn *)(buf + offset); > > + opt_len =3D encode_domain_name(o->domain_name, opt_len, c->fqdn, = strlen(c->fqdn)); > > This now exceeds 80 columns. > Done. > > + if (opt_len =3D=3D -1) { > > + debug("DHCPv6: client FQDN option does not fit, skipping"= ); > > + return offset; > > + } > > + > > + req_opt =3D (struct opt_client_fqdn *)dhcpv6_opt(p, &(size_t){ 0 = }, > > + OPT_CLIENT_FQDN); > > + if (req_opt && req_opt->flags & 0x01 /* S flag */) > > + o->flags =3D 0x02 /* O flag */; > > + else > > + o->flags =3D 0x00; > > + > > + opt_len++; > > + > > + o->hdr.t =3D OPT_CLIENT_FQDN; > > + o->hdr.l =3D htons(opt_len); > > It's much easier to follow now, I think. > > > + > > + return offset + sizeof(struct opt_hdr) + opt_len; > > +} > > + > > /** > > * dhcpv6() - Check if this is a DHCPv6 message, reply as needed > > * @c: Execution context > > @@ -544,6 +598,7 @@ int dhcpv6(struct ctx *c, const struct pool *p, > > n =3D offsetof(struct resp_t, client_id) + > > sizeof(struct opt_hdr) + ntohs(client_id->l); > > n =3D dhcpv6_dns_fill(c, (char *)&resp, n); > > + n =3D dhcpv6_client_fqdn_fill(p, c, (char *)&resp, n); > > > > resp.hdr.xid =3D mh->xid; > > > > diff --git a/passt.1 b/passt.1 > > index d9cd33e..7051fc4 100644 > > --- a/passt.1 > > +++ b/passt.1 > > @@ -401,6 +401,16 @@ Enable IPv6-only operation. IPv4 traffic will be i= gnored. > > By default, IPv4 operation is enabled as long as at least an IPv4 rout= e and an > > interface address are configured on a given host interface. > > > > +.TP > > +.BR \-H ", " \-\-hostname " " \fIname > > +Hostname to configure the client with. > > +Send \fIname\fR as DHCP option 12 (hostname). > > + > > +.TP > > +.BR \-\-fqdn " " \fIname > > +FQDN to configure the client with. > > +Send \fIname\fR as Client FQDN: DHCP option 81 and DHCPv6 option 39. > > + > > .SS \fBpasst\fR-only options > > > > .TP > > diff --git a/passt.h b/passt.h > > index 0dd4efa..f3151f0 100644 > > --- a/passt.h > > +++ b/passt.h > > @@ -209,6 +209,8 @@ struct ip6_ctx { > > * @ifi4: Template interface for IPv4, -1: none, 0: IPv4 di= sabled > > * @ip: IPv4 configuration > > * @dns_search: DNS search list > > + * @hostname: Guest hostname > > + * @fqdn: Guest FQDN > > * @ifi6: Template interface for IPv6, -1: none, 0: IPv6 di= sabled > > * @ip6: IPv6 configuration > > * @pasta_ifn: Name of namespace interface for pasta > > @@ -269,6 +271,9 @@ struct ctx { > > > > struct fqdn dns_search[MAXDNSRCH]; > > > > + char hostname[PASST_MAXDNAME]; > > + char fqdn[PASST_MAXDNAME]; > > + > > int ifi6; > > struct ip6_ctx ip6; > > > > diff --git a/pasta.c b/pasta.c > > index ff41c95..f3b4cae 100644 > > --- a/pasta.c > > +++ b/pasta.c > > @@ -169,10 +169,12 @@ void pasta_open_ns(struct ctx *c, const char *net= ns) > > * struct pasta_spawn_cmd_arg - Argument for pasta_spawn_cmd() > > * @exe: Executable to run > > * @argv: Command and arguments to run > > + * @ctx: Context to read config from > > */ > > struct pasta_spawn_cmd_arg { > > const char *exe; > > char *const *argv; > > + struct ctx *c; > > }; > > > > /** > > @@ -186,6 +188,7 @@ static int pasta_spawn_cmd(void *arg) > > { > > char hostname[HOST_NAME_MAX + 1] =3D HOSTNAME_PREFIX; > > const struct pasta_spawn_cmd_arg *a; > > + size_t conf_hostname_len; > > sigset_t set; > > > > /* We run in a detached PID and mount namespace: mount /proc over= */ > > @@ -195,9 +198,15 @@ static int pasta_spawn_cmd(void *arg) > > if (write_file("/proc/sys/net/ipv4/ping_group_range", "0 0")) > > warn("Cannot set ping_group_range, ICMP requests might fa= il"); > > > > - if (!gethostname(hostname + sizeof(HOSTNAME_PREFIX) - 1, > > - HOST_NAME_MAX + 1 - sizeof(HOSTNAME_PREFIX)) || > > - errno =3D=3D ENAMETOOLONG) { > > + a =3D (const struct pasta_spawn_cmd_arg *)arg; > > + > > + conf_hostname_len =3D strlen(a->c->hostname); > > + if (conf_hostname_len > 0) { > > + if (sethostname(a->c->hostname, conf_hostname_len)) > > + warn("Unable to set configured hostname"); > > + } else if (!gethostname(hostname + sizeof(HOSTNAME_PREFIX) - 1, > > + HOST_NAME_MAX + 1 - sizeof(HOSTNAME_PREFIX)) || > > + errno =3D=3D ENAMETOOLONG) { > > Same as my comment to v6, which was the same as my comment to v5...: > > "Same as for v5: this is an argument to gethostname(), so it should be > aligned accordingly. ! is a unary operator, it doesn't take two operands. > > That is: > > } else if (!gethostname(hostname + sizeof(HOSTNAME_PREFIX) - 1, > HOST_NAME_MAX + 1 - sizeof(HOSTNAME_PREFI= X)) || > > see also the version without your patch." > > > hostname[HOST_NAME_MAX] =3D '\0'; > > if (sethostname(hostname, strlen(hostname))) > > warn("Unable to set pasta-prefixed hostname"); Done. > > @@ -208,7 +217,6 @@ static int pasta_spawn_cmd(void *arg) > > sigaddset(&set, SIGUSR1); > > sigwaitinfo(&set, NULL); > > > > - a =3D (const struct pasta_spawn_cmd_arg *)arg; > > execvp(a->exe, a->argv); > > > > die_perror("Failed to start command or shell"); > > @@ -230,6 +238,7 @@ void pasta_start_ns(struct ctx *c, uid_t uid, gid_t= gid, > > struct pasta_spawn_cmd_arg arg =3D { > > .exe =3D argv[0], > > .argv =3D argv, > > + .c =3D c, > > }; > > char uidmap[BUFSIZ], gidmap[BUFSIZ]; > > char *sh_argv[] =3D { NULL, NULL }; > > diff --git a/test/lib/setup b/test/lib/setup > > index 580825f..ee67152 100755 > > --- a/test/lib/setup > > +++ b/test/lib/setup > > @@ -49,7 +49,7 @@ setup_passt() { > > > > context_run passt "make clean" > > context_run passt "make valgrind" > > - context_run_bg passt "valgrind --max-stackframe=3D$((4 * 1024 * 1= 024)) --trace-children=3Dyes --vgdb=3Dno --error-exitcode=3D1 --suppression= s=3Dtest/valgrind.supp ./passt ${__opts} -s ${STATESETUP}/passt.socket -f -= t 10001 -u 10001 -P ${STATESETUP}/passt.pid" > > + context_run_bg passt "valgrind --max-stackframe=3D$((4 * 1024 * 1= 024)) --trace-children=3Dyes --vgdb=3Dno --error-exitcode=3D1 --suppression= s=3Dtest/valgrind.supp ./passt ${__opts} -s ${STATESETUP}/passt.socket -f -= t 10001 -u 10001 -H hostname1 --fqdn fqdn1.passt.test -P ${STATESETUP}/pass= t.pid" > > > > # pidfile isn't created until passt is listening > > wait_for [ -f "${STATESETUP}/passt.pid" ] > > @@ -160,11 +160,11 @@ setup_passt_in_ns() { > > if [ ${VALGRIND} -eq 1 ]; then > > context_run passt "make clean" > > context_run passt "make valgrind" > > - context_run_bg passt "valgrind --max-stackframe=3D$((4 * = 1024 * 1024)) --trace-children=3Dyes --vgdb=3Dno --error-exitcode=3D1 --sup= pressions=3Dtest/valgrind.supp ./passt -f ${__opts} -s ${STATESETUP}/passt.= socket -t 10001,10011,10021,10031 -u 10001,10011,10021,10031 -P ${STATESETU= P}/passt.pid --map-host-loopback ${__map_ns4} --map-host-loopback ${__map_n= s6}" > > + context_run_bg passt "valgrind --max-stackframe=3D$((4 * = 1024 * 1024)) --trace-children=3Dyes --vgdb=3Dno --error-exitcode=3D1 --sup= pressions=3Dtest/valgrind.supp ./passt -f ${__opts} -s ${STATESETUP}/passt.= socket -H hostname1 --fqdn fqdn1.passt.test -t 10001,10011,10021,10031 -u 1= 0001,10011,10021,10031 -P ${STATESETUP}/passt.pid --map-host-loopback ${__m= ap_ns4} --map-host-loopback ${__map_ns6}" > > else > > context_run passt "make clean" > > context_run passt "make" > > - context_run_bg passt "./passt -f ${__opts} -s ${STATESETU= P}/passt.socket -t 10001,10011,10021,10031 -u 10001,10011,10021,10031 -P ${= STATESETUP}/passt.pid --map-host-loopback ${__map_ns4} --map-host-loopback = ${__map_ns6}" > > + context_run_bg passt "./passt -f ${__opts} -s ${STATESETU= P}/passt.socket -H hostname1 --fqdn fqdn1.passt.test -t 10001,10011,10021,1= 0031 -u 10001,10011,10021,10031 -P ${STATESETUP}/passt.pid --map-host-loopb= ack ${__map_ns4} --map-host-loopback ${__map_ns6}" > > fi > > wait_for [ -f "${STATESETUP}/passt.pid" ] > > > > @@ -243,7 +243,7 @@ setup_two_guests() { > > [ ${TRACE} -eq 1 ] && __opts=3D"${__opts} --trace" > > [ ${VHOST_USER} -eq 1 ] && __opts=3D"${__opts} --vhost-user" > > > > - context_run_bg passt_1 "./passt -s ${STATESETUP}/passt_1.socket -= P ${STATESETUP}/passt_1.pid -f ${__opts} -t 10001 -u 10001" > > + context_run_bg passt_1 "./passt -s ${STATESETUP}/passt_1.socket -= P ${STATESETUP}/passt_1.pid -f ${__opts} --fqdn fqdn1.passt.test -H hostnam= e1 -t 10001 -u 10001" > > wait_for [ -f "${STATESETUP}/passt_1.pid" ] > > > > __opts=3D > > @@ -252,7 +252,7 @@ setup_two_guests() { > > [ ${TRACE} -eq 1 ] && __opts=3D"${__opts} --trace" > > [ ${VHOST_USER} -eq 1 ] && __opts=3D"${__opts} --vhost-user" > > > > - context_run_bg passt_2 "./passt -s ${STATESETUP}/passt_2.socket -= P ${STATESETUP}/passt_2.pid -f ${__opts} -t 10004 -u 10004" > > + context_run_bg passt_2 "./passt -s ${STATESETUP}/passt_2.socket -= P ${STATESETUP}/passt_2.pid -f ${__opts} --hostname hostname2 --fqdn fqdn2 = -t 10004 -u 10004" > > wait_for [ -f "${STATESETUP}/passt_2.pid" ] > > > > __vmem=3D"$((${MEM_KIB} / 1024 / 4))" > > diff --git a/test/passt.mbuto b/test/passt.mbuto > > index 138d365..1e07693 100755 > > --- a/test/passt.mbuto > > +++ b/test/passt.mbuto > > @@ -13,7 +13,7 @@ > > PROGS=3D"${PROGS:-ash,dash,bash ip mount ls insmod mkdir ln cat chmod = lsmod > > modprobe find grep mknod mv rm umount jq iperf3 dhclient hostna= me > > sed tr chown sipcalc cut socat dd strace ping tail killall slee= p sysctl > > - nproc tcp_rr tcp_crr udp_rr which tee seq bc sshd ssh-keygen cm= p}" > > + nproc tcp_rr tcp_crr udp_rr which tee seq bc sshd ssh-keygen cm= p env}" > > > > # OpenSSH 9.8 introduced split binaries, with sshd being the daemon, a= nd > > # sshd-session the per-session program. We need the latter as well, an= d the path > > @@ -41,6 +41,7 @@ FIXUP=3D"${FIXUP}"' > > #!/bin/sh > > LOG=3D/var/log/dhclient-script.log > > echo \${reason} \${interface} >> \$LOG > > +env >> \$LOG > > set >> \$LOG > > > > [ -n "\${new_interface_mtu}" ] && ip link set dev \${interface} = mtu \${new_interface_mtu} > > @@ -54,7 +55,8 @@ set >> \$LOG > > [ -n "\${new_ip6_address}" ] && ip addr add \${new_ip6_address= }/\${new_ip6_prefixlen} dev \${interface} > > [ -n "\${new_dhcp6_name_servers}" ] && for d in \${new_dhcp6_name_ser= vers}; do echo "nameserver \${d}%\${interface}" >> /etc/resolv.conf; done > > [ -n "\${new_dhcp6_domain_search}" ] && (printf "search"; for d in \${= new_dhcp6_domain_search}; do printf " %s" "\${d}"; done; printf "\n") >> /e= tc/resolv.conf > > -[ -n "\${new_host_name}" ] && hostname "\${new_host_name}" > > +[ -n "\${new_host_name}" ] && echo "\${new_host_name}" > /tm= p/new_host_name > > +[ -n "\${new_fqdn_fqdn}" ] && echo "\${new_fqdn_fqdn}" > /tm= p/new_fqdn_fqdn > > exit 0 > > EOF > > chmod 755 /sbin/dhclient-script > > diff --git a/test/passt/dhcp b/test/passt/dhcp > > index 9925ab9..145f1ba 100644 > > --- a/test/passt/dhcp > > +++ b/test/passt/dhcp > > @@ -11,7 +11,7 @@ > > # Copyright (c) 2021 Red Hat GmbH > > # Author: Stefano Brivio > > > > -gtools ip jq dhclient sed tr > > +gtools ip jq dhclient sed tr hostname > > htools ip jq sed tr head > > > > test Interface name > > @@ -47,7 +47,16 @@ gout SEARCH sed 's/\. / /g' /etc/resolv.conf |= sed 's/\.$//g' | sed -n 's/^searc > > hout HOST_SEARCH sed 's/\. / /g' /etc/resolv.conf | sed 's/\.$//g' | s= ed -n 's/^search \(.*\)/\1/p' | tr ' \n' ',' | sed 's/,$//;s/$/\n/' > > check [ "__SEARCH__" =3D "__HOST_SEARCH__" ] > > > > +test DHCP: Hostname > > +gout NEW_HOST_NAME cat /tmp/new_host_name > > +check [ "__NEW_HOST_NAME__" =3D "hostname1" ] > > + > > +test DHCP: Client FQDN > > +gout NEW_FQDN_FQDN cat /tmp/new_fqdn_fqdn > > +check [ "__NEW_FQDN_FQDN__" =3D "fqdn1.passt.test" ] > > + > > test DHCPv6: address > > +guest rm /tmp/new_fqdn_fqdn > > guest /sbin/dhclient -6 __IFNAME__ > > # Wait for DAD to complete > > guest while ip -j -6 addr show tentative | jq -e '.[].addr_info= '; do sleep 0.1; done > > @@ -70,3 +79,7 @@ test DHCPv6: search list > > gout SEARCH6 sed 's/\. / /g' /etc/resolv.conf | sed 's/\.$//g' | sed -= n 's/^search \(.*\)/\1/p' | tr ' \n' ',' | sed 's/,$//;s/$/\n/' > > hout HOST_SEARCH6 sed 's/\. / /g' /etc/resolv.conf | sed 's/\.$//g' | = sed -n 's/^search \(.*\)/\1/p' | tr ' \n' ',' | sed 's/,$//;s/$/\n/' > > check [ "__SEARCH6__" =3D "__HOST_SEARCH6__" ] > > + > > +test DHCPv6: Hostname > > +gout NEW_FQDN_FQDN cat /tmp/new_fqdn_fqdn > > +check [ "__NEW_FQDN_FQDN__" =3D "fqdn1.passt.test" ] > > diff --git a/util.c b/util.c > > index 11973c4..ba876ea 100644 > > --- a/util.c > > +++ b/util.c > > @@ -837,3 +837,34 @@ void raw_random(void *buf, size_t buflen) > > if (random_read < buflen) > > die("Unexpected EOF on random data source"); > > } > > +/** > > + * encode_domain_name() - Encode domain name according to RFC 1035, se= ction 3.1 > > + * @buf: Buffer to fill in with encoded domain name > > + * @len Buffer length > > @len: > Done. > > + * @domain_name: Input domain name > > + * @domain_name_len Domain name length > > @domain_name_len: > Done. > > + * > > + * Return: encoded domain name length or -1 if it do not fit at buffer > > "doesn't" > > "fit in the buffer" (or simply "doesn't fit") > Done. > > + */ > > +ssize_t encode_domain_name(char *buf, size_t len, const char *domain_n= ame, size_t domain_name_len) > > This now exceeds 80 columns for no compelling reason. > Done. > > +{ > > + char *p; > > + size_t i; > > These should go from longest to shortest. > Done. > > + > > + if (domain_name_len + 2 > len) > > + return -1; > > + > > + buf[0] =3D strcspn(domain_name, "."); > > + p =3D buf + 1; > > + for (i =3D 0; i < len; i++) { > > + if (domain_name[i] =3D=3D '.') > > This overflows the *input* buffer, if len > domain_name_len (which is > the intended usage). > > I understand that if you limit len in the caller (<=3D PASST_MAXDNAME), > then you avoid the overflow, but this looks extremely fragile (the > restriction in the caller is buggy anyway), and it would leak host > memory into the guest. > > I still think that v6 plus my suggestion (ensure adequate buffer size > in the caller) would be a bit simpler. > > If you really want to add a check on the output buffer size here, I > would suggest that you iterate over the *input* bytes anyway, and then > at every byte check that you're not exceeding the output buffer. > So your suggestion is at the caller limiting|check buffer size and not pass domain_name len, so function will be: size_t encode_domain_name(char* buf, const char *domain_name) That means that the caller has to know that the encoded len is len (without terminator) + 2, is that fine ? The idea for v7 was encapsulating the size check at the function so we don't have to repeat len + 2 check at all the callers, but maybe is plain overengineering stuff. > > + p[i] =3D strcspn(domain_name + i + 1, "."); > > + else > > + p[i] =3D domain_name[i]; > > + } > > + > > + /* domain name is terminated by a length byte of zero */ > > + p[len + 1] =3D 0x00; > > + > > + return domain_name_len + 2; > > +} > > diff --git a/util.h b/util.h > > index 3fa1d12..b7d5b91 100644 > > --- a/util.h > > +++ b/util.h > > @@ -40,6 +40,9 @@ > > #ifndef IP_MAX_MTU > > #define IP_MAX_MTU USHRT_MAX > > #endif > > +#ifndef IPV6_MIN_MTU > > +#define IPV6_MIN_MTU 1280 > > This would need tabs instead of spaces (even better: align it with the > other values above, so that it becomes some kind of table). > Done. > > +#endif > > > > #ifndef MIN > > #define MIN(x, y) (((x) < (y)) ? (x) : (y)) > > @@ -346,4 +349,7 @@ static inline int wrap_accept4(int sockfd, struct s= ockaddr *addr, > > #define accept4(s, addr, addrlen, flags) \ > > wrap_accept4((s), (addr), (addrlen), (flags)) > > > > +#define PASST_MAXDNAME 253 /* RFC 1035 */ > > +ssize_t encode_domain_name(char *buf, size_t len, const char *domain_n= ame, size_t domain_name_len); > > This exceeds 80 columns and can conveniently be wrapped. > > > + > > #endif /* UTIL_H */ > > -- > Stefano > -- Quique Llorente CNV networking Senior Software Engineer Red Hat EMEA ellorent@redhat.com @RedHat Red Hat Red Hat