On Wed, Jul 01, 2026 at 02:07:50AM +0200, Stefano Brivio wrote: > On Fri, 26 Jun 2026 17:10:01 +1000 > David Gibson wrote: > > > The -a command line option can take either an address prefix, or a bare > > address. Current parsing of this is pretty awkward, using the special > > purpose helper inany_prefix_pton(). With the new incremental parsing > > helpers this can be done more naturally. Rework it to use them. > > > > This does requiring extending parse_inany() to parse_inany_() which also > > reports the format of the address as parse, as opposed to the family of > > the resulting address. This is so that ::ffff:192.0.1.1/112 will be > > correctly interpreted the same as 192.0.1.1/16, rather than the > > nonsensical 192.0.0.1/112. > > By the way, as far as I know, ::ffff:192.0.1.1/112 is not a valid > address, because IPv4-mapped addresses must always have /96 as prefix > length (see RFC 6890, Table 20). AFAICT the /96 there is just indicating the size of the v4-mapped block, not saying you can't have longer prefixes within that block. > RFC 6052 adds some madness (e.g. 2001:db8:122:344::192.0.2.33 from > Table 1) on top, but as far as I understand you can't use that for > prefixes. > > > > > Cc: Jon Maloy > > > > Signed-off-by: David Gibson > > --- > > Makefile | 1 - > > conf.c | 63 +++++++++++++++++++++++++++++++++++--------------------- > > inany.c | 50 -------------------------------------------- > > inany.h | 2 -- > > parse.c | 17 ++++++++++++--- > > parse.h | 5 ++++- > > 6 files changed, 58 insertions(+), 80 deletions(-) > > > > diff --git a/Makefile b/Makefile > > index e2b22ddf..5757aeff 100644 > > --- a/Makefile > > +++ b/Makefile > > @@ -223,7 +223,6 @@ passt-repair.cppcheck: $(PASST_REPAIR_SRCS) $(PASST_REPAIR_HEADERS) seccomp_repa > > pesto.cppcheck: BASE_CPPFLAGS += -DPESTO > > pesto.cppcheck: CPPCHECK_FLAGS += --suppress=unusedFunction:bitmap.c > > pesto.cppcheck: CPPCHECK_FLAGS += --suppress=unusedFunction:inany.h > > -pesto.cppcheck: CPPCHECK_FLAGS += --suppress=unusedFunction:inany.c > > pesto.cppcheck: CPPCHECK_FLAGS += --suppress=unusedFunction:ip.h > > pesto.cppcheck: CPPCHECK_FLAGS += --suppress=unusedFunction:serialise.c > > pesto.cppcheck: CPPCHECK_FLAGS += --suppress=staticFunction:fwd_rule.c > > diff --git a/conf.c b/conf.c > > index 3614776c..ff7ca5c7 100644 > > --- a/conf.c > > +++ b/conf.c > > @@ -1176,43 +1176,60 @@ int conf_tap_fd(const char *arg) > > */ > > static bool conf_addr(struct ctx *c, char *arg, uint8_t opt_n) > > { > > + unsigned long prefix_len; > > + const struct in_addr *a4; > > union inany_addr addr; > > + sa_family_t parseaf; > > I think parse_af would be more readable (and also more consistent with > e.g. prefix_len). Sure. > > const char *p = arg; > > - uint8_t prefix_len; > > bool is_prefix; > > > > - is_prefix = inany_prefix_pton(arg, &addr, &prefix_len); > > - > > - if (is_prefix && opt_n) > > - die("Redundant prefix length specification"); > > - > > - if (!is_prefix && > > - !(parse_inany(&p, &addr) && parse_eoi(p))) > > - die("Invalid address: %s", arg); > > - > > - if (opt_n && inany_v4(&addr)) > > - prefix_len = opt_n; > > - else if (!is_prefix) > > - prefix_len = inany_default_prefix_len(&addr); > > + if (!parse_inany_(&p, &addr, &parseaf)) > > ...just call it af? It doesn't matter so much in the following code > where that comes from. Starting from here, we know it's the address > family we're using. Eh.. I don't like that, because just "af" suggests it's the address family of the address itself. That's not the case - it's very specifically the address family of the *string* not the resulting address. > > + goto bad; > > + a4 = inany_v4(&addr); > > + > > + if ((is_prefix = parse_literal(&p, "/"))) { > > The current return convention makes more sense here, but I wouldn't > find: > > is_prefix = !parse_literal(&p, "/") > > outrageous, either. > > > + /* Prefix length included in -a option */ > > + if (!parse_unsigned(&p, 10, &prefix_len)) > > + goto bad; > > + if (opt_n) > > + die("Redundant prefix length specification"); > > + if (parseaf == AF_INET) { > > + if (prefix_len > 32) > > + goto bad_prefix; > > + prefix_len += 96; > > + } else if (prefix_len > 128) { > > + goto bad_prefix; > > + } > > + } else { > > + /* Get prefix length from elsewhere */ > > + if (opt_n && a4) > > + prefix_len = opt_n; > > + else > > + prefix_len = inany_default_prefix_len(&addr); > > + } > > > > - if (inany_is_unspecified(&addr) || inany_is_multicast(&addr) || > > - inany_is_loopback(&addr) || IN6_IS_ADDR_V4COMPAT(&addr.a6)) > > - die("Invalid address: %s", arg); > > + if (!parse_eoi(p) || > > Note: with *p instead of !parse_eoi(), this would fit on one line. > > > + !inany_is_unicast(&addr) || > > + inany_is_loopback(&addr)) > > + goto bad; > > > > - if (inany_v4(&addr)) { > > - c->ip4.addr = *inany_v4(&addr); > > + if (a4) { > > + c->ip4.addr = *a4; > > c->ip4.prefix_len = prefix_len - 96; > > c->ip4.addr_fixed = true; > > - if (c->mode == MODE_PASTA) > > Why does this (and the same condition just below) go away here? I mean, > it's not fundamental in any case, but changing it here makes it look > like it has something to do with this change (and I guess it's not the > case). Good point, that's an unrelated change. I split it into its own patch. > > > - c->ip4.no_copy_addrs = true; > > + c->ip4.no_copy_addrs = true; > > } else { > > c->ip6.addr = addr.a6; > > c->ip6.addr_fixed = true; > > - if (c->mode == MODE_PASTA) > > - c->ip6.no_copy_addrs = true; > > + c->ip6.no_copy_addrs = true; > > } > > > > return is_prefix; > > + > > +bad_prefix: > > + die("Invalid prefix length: %s", arg); > > +bad: > > + die("Invalid guest address: %s", arg); > > } > > > > /** > > diff --git a/inany.c b/inany.c > > index 154f08b5..120c9387 100644 > > --- a/inany.c > > +++ b/inany.c > > @@ -70,53 +70,3 @@ const char *inany_ntop(const union inany_addr *src, char *dst, socklen_t size) > > > > return inet_ntop(AF_INET6, &src->a6, dst, size); > > } > > - > > -/** > > - * inany_prefix_pton() - Parse an IPv[46] address with prefix length > > - * @src: IPv[46] address and prefix length string in CIDR format > > - * @dst: Output buffer, filled with parsed address > > - * @prefix_len: Prefix length, to be filled in IPv6 format > > - * > > - * Return: 1 on success, 0 if no parseable address or prefix is found > > - */ > > -int inany_prefix_pton(const char *src, union inany_addr *dst, > > - uint8_t *prefix_len) > > -{ > > - char astr[INANY_ADDRSTRLEN] = { 0 }; > > - size_t alen = strcspn(src, "/"); > > - const char *pstr = &src[alen + 1]; > > - const char *p = astr; > > - unsigned long plen; > > - char *end; > > - > > - if (alen >= INANY_ADDRSTRLEN) > > - return 0; > > - > > - if (src[alen] != '/') > > - return 0; > > - > > - strncpy(astr, src, alen); > > - > > - /* Read prefix length */ > > - errno = 0; > > - plen = strtoul(pstr, &end, 10); > > - if (errno || *end || plen > 128) > > - return 0; > > - > > - /* Read address */ > > - if (inet_pton(AF_INET6, astr, dst)) { > > - if (inany_v4(dst) && plen < 96) > > - return 0; > > - *prefix_len = plen; > > - return 1; > > - } > > - > > - if (parse_inany(&p, dst) && parse_eoi(p)) { > > - if (plen > 32) > > - return 0; > > - *prefix_len = plen + 96; > > - return 1; > > - } > > - > > - return 0; > > -} > > diff --git a/inany.h b/inany.h > > index 93d98368..5b176ccf 100644 > > --- a/inany.h > > +++ b/inany.h > > @@ -303,7 +303,5 @@ static inline int inany_from_sockaddr(union inany_addr *dst, in_port_t *port, > > > > bool inany_matches(const union inany_addr *a, const union inany_addr *b); > > const char *inany_ntop(const union inany_addr *src, char *dst, socklen_t size); > > -int inany_prefix_pton(const char *src, union inany_addr *dst, > > - uint8_t *prefix_len); > > > > #endif /* INANY_H */ > > diff --git a/parse.c b/parse.c > > index 0349c5dc..3e0dbd45 100644 > > --- a/parse.c > > +++ b/parse.c > > @@ -184,18 +184,29 @@ static bool parse_ipv6(const char **cursor, struct in6_addr *abuf) > > } > > > > /** > > - * parse_inany() - Parse an IPv4 or IPv6 address from a string > > + * parse_inany_() - Parse an IPv4 or IPv6 address from a string > > * @addr: On success, updated with parsed address > > + * @parseaf: On success, updated with the format of the parsed address > > + * > > + * @parseaf is updated to reflect the string format, not the final address > > + * family. So "::ffff:192.0.1.1", will set @parseaf to AF_INET6, despite being > > + * a IPv4-mapped address. > > */ > > -bool parse_inany(const char **cursor, union inany_addr *addr) > > +bool parse_inany_(const char **cursor, union inany_addr *addr, > > + sa_family_t *parseaf) > > { > > struct in_addr a4; > > > > - if (parse_ipv6(cursor, &addr->a6)) > > + if (parse_ipv6(cursor, &addr->a6)) { > > + if (parseaf) > > + *parseaf = AF_INET6; > > return true; > > + } > > > > if (parse_ipv4(cursor, &a4)) { > > *addr = inany_from_v4(a4); > > + if (parseaf) > > + *parseaf = AF_INET; > > return true; > > } > > > > diff --git a/parse.h b/parse.h > > index 2820a065..08b038cf 100644 > > --- a/parse.h > > +++ b/parse.h > > @@ -27,6 +27,9 @@ bool parse_eoi(const char *cursor); > > bool parse_unsigned(const char **cursor, int base, unsigned long *valp); > > bool parse_port_range(const char **cursor, struct port_range *range); > > bool parse_ipv4(const char **cursor, struct in_addr *abuf); > > -bool parse_inany(const char **cursor, union inany_addr *addr); > > +bool parse_inany_(const char **cursor, union inany_addr *addr, > > + sa_family_t *parseaf); > > + > > +#define parse_inany(cursor, addr) parse_inany_((cursor), (addr), NULL) > > > > #endif /* _PARSE_H */ > > -- > Stefano > -- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson