The new action inheritdsfield copies the field DS of IPv4 and IPv6 packets into skb->priority. This enables later classification of packets based on the DS field.
Original idea by Jamal Hadi Salim <j...@mojatatu.com> Signed-off-by: Qiaobin Fu <qiaob...@bu.edu> Reviewed-by: Michel Machado <mic...@digirati.com.br> --- Note that the motivation for this patch is found in the following discussion: https://www.spinics.net/lists/netdev/msg501061.html --- diff --git a/include/uapi/linux/tc_act/tc_skbedit.h b/include/uapi/linux/tc_act/tc_skbedit.h index fbcfe27..432ad2f 100644 --- a/include/uapi/linux/tc_act/tc_skbedit.h +++ b/include/uapi/linux/tc_act/tc_skbedit.h @@ -30,9 +30,11 @@ #define SKBEDIT_F_MARK 0x4 #define SKBEDIT_F_PTYPE 0x8 #define SKBEDIT_F_MASK 0x10 +#define SKBEDIT_F_INHERITDSFIELD 0x20 struct tc_skbedit { tc_gen; + __u64 flags; }; enum { diff --git a/tc/m_skbedit.c b/tc/m_skbedit.c index db5c64c..7553a40 100644 --- a/tc/m_skbedit.c +++ b/tc/m_skbedit.c @@ -30,16 +30,18 @@ static void explain(void) { - fprintf(stderr, "Usage: ... skbedit <[QM] [PM] [MM] [PT]>\n" + fprintf(stderr, "Usage: ... skbedit <[QM] [PM] [MM] [PT] [IF]>\n" "QM = queue_mapping QUEUE_MAPPING\n" "PM = priority PRIORITY\n" "MM = mark MARK\n" "PT = ptype PACKETYPE\n" + "IF = inheritdsfield\n" "PACKETYPE = is one of:\n" " host, otherhost, broadcast, multicast\n" "QUEUE_MAPPING = device transmit queue to use\n" "PRIORITY = classID to assign to priority field\n" - "MARK = firewall mark to set\n"); + "MARK = firewall mark to set\n" + "note: inheritdsfield maps DS field to skb->priority\n"); } static void @@ -59,7 +61,7 @@ parse_skbedit(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, struct rtattr *tail; unsigned int tmp; __u16 queue_mapping, ptype; - __u32 flags = 0, priority, mark; + __u32 priority, mark; struct tc_skbedit sel = { 0 }; if (matches(*argv, "skbedit") != 0) @@ -69,7 +71,7 @@ parse_skbedit(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, while (argc > 0) { if (matches(*argv, "queue_mapping") == 0) { - flags |= SKBEDIT_F_QUEUE_MAPPING; + sel.flags |= SKBEDIT_F_QUEUE_MAPPING; NEXT_ARG(); if (get_unsigned(&tmp, *argv, 10) || tmp > 65535) { fprintf(stderr, "Illegal queue_mapping\n"); @@ -78,7 +80,7 @@ parse_skbedit(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, queue_mapping = tmp; ok++; } else if (matches(*argv, "priority") == 0) { - flags |= SKBEDIT_F_PRIORITY; + sel.flags |= SKBEDIT_F_PRIORITY; NEXT_ARG(); if (get_tc_classid(&priority, *argv)) { fprintf(stderr, "Illegal priority\n"); @@ -86,7 +88,7 @@ parse_skbedit(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, } ok++; } else if (matches(*argv, "mark") == 0) { - flags |= SKBEDIT_F_MARK; + sel.flags |= SKBEDIT_F_MARK; NEXT_ARG(); if (get_u32(&mark, *argv, 0)) { fprintf(stderr, "Illegal mark\n"); @@ -109,7 +111,10 @@ parse_skbedit(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, *argv); return -1; } - flags |= SKBEDIT_F_PTYPE; + sel.flags |= SKBEDIT_F_PTYPE; + ok++; + } else if (matches(*argv, "inheritdsfield") == 0) { + sel.flags |= SKBEDIT_F_INHERITDSFIELD; ok++; } else if (matches(*argv, "help") == 0) { usage(); @@ -144,16 +149,16 @@ parse_skbedit(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, tail = addattr_nest(n, MAX_MSG, tca_id); addattr_l(n, MAX_MSG, TCA_SKBEDIT_PARMS, &sel, sizeof(sel)); - if (flags & SKBEDIT_F_QUEUE_MAPPING) + if (sel.flags & SKBEDIT_F_QUEUE_MAPPING) addattr_l(n, MAX_MSG, TCA_SKBEDIT_QUEUE_MAPPING, &queue_mapping, sizeof(queue_mapping)); - if (flags & SKBEDIT_F_PRIORITY) + if (sel.flags & SKBEDIT_F_PRIORITY) addattr_l(n, MAX_MSG, TCA_SKBEDIT_PRIORITY, &priority, sizeof(priority)); - if (flags & SKBEDIT_F_MARK) + if (sel.flags & SKBEDIT_F_MARK) addattr_l(n, MAX_MSG, TCA_SKBEDIT_MARK, &mark, sizeof(mark)); - if (flags & SKBEDIT_F_PTYPE) + if (sel.flags & SKBEDIT_F_PTYPE) addattr_l(n, MAX_MSG, TCA_SKBEDIT_PTYPE, &ptype, sizeof(ptype)); addattr_nest_end(n, tail); @@ -211,6 +216,8 @@ static int print_skbedit(struct action_util *au, FILE *f, struct rtattr *arg) else fprintf(f, " ptype %d", *ptype); } + if (p->flags & SKBEDIT_F_INHERITDSFIELD) + fprintf(f, "inherit DS field "); print_action_control(f, " ", p->action, "");
